Category Archives: dermatology

Biotin: the lack of science behind its use as a hair supplement

Continuing my hair care series, I thought this topic is definitely worth writing about. Biotin (vitamin B7) supplements has been widely popularised for the treatment of hair fall and thinning hair. It’s promised to help grow long, thick, luscious hair and for healthy nails as well.

But is there a rational scientific evidence behind this popular trend?

I’m here to discuss the science (or more like the lack of it) behind the use of biotin supplements for hair loss.

What is biotin?

Biotin is a water soluble vitamin, and functions as a co-factor for various enzymes responsible for energy production in our body. Being water soluble means it does not get stored in the body and is excreted in the urine via the kidneys. So chances of toxicity from over consumption of biotin is minimal and so far there has not been any adverse effects from biotin supplementation. This being said, biotin supplementations for general well being or for healthy nails and hair is still not justified!!

The recommended daily allowance of biotin is 30 µg per day.

And we meet this requirement adequately from our diet.

If less is good, is more better?
from my dermatology text book

My answer to this question when it comes to nutrients for our body, is NO!! More is definitely not better and more is actually un necessary.

So why is biotin heavily popularised?

Few reported cases of biotinase (an enzyme required for recycling biotin in our body) deficiency was reported in infants and children who inherited the disease due to genetic mutations. It was noted that few of these cases had alopecia (hair loss) with or without brittle nails. Biotin helped improve the hair and nail changes in these cases.

Thus stemmed the popular trend of biotin supplements for hair fall or nail disorders.There is no regulation on vitamin supplementation production, hence pharmaceutical companies take advantage of this and advertise and market biotin supplements as a saviour for hair loss.

Note: in these cases describes above, biotin was a treatment of choice because they lacked biotin in their body.

Biotin deficiency in general population is very rare as we get adequate amounts from our diet. Supplementation of high doses (500-1000 µg/ day when the required amount is only ~ 30 µg/ day) is highly unjustified.

The few rare instances when a person can develop biotin deficiency are:

So does biotin also improve hair loss in healthy individuals without its deficiency?

There has never been any scientific study on the effectiveness of biotin for the treatment of hair loss in healthy individuals.

A study on 541 women with hair loss, showed that only 38% of these individuals had biotin deficiency of which 11% had histories on being on long term medications that can cause biotin deficiency and 35% of these women also had co-existing skin condition called seborrheic dermatitis, which shows that in individuals with hair loss, majority had normal levels of biotin and supplementation was un-necessary.

Even lab studies found that the differentiation and proliferation (growth) of the follicular keratinocytes (cells in the hair follicle) was unaffected by the level of biotin.

Biotin supplementation is not the treatment for hair loss/ hair thinning nor does its intake help aid other scientifically proven treatments for hair loss

Can biotin supplements do any harm?

Like I’ve mentioned earlier, there are no known toxicities reported so far as a result of biotin supplementation.

However, excessive amount of biotin in the blood can interfere with many of the laboratory investigations such as thyroid function tests, other hormonal profiles as well as levels of troponin in the blood (which is an indicator of a heart attack).

Many lab tests rely on a biotin-streptavidin reaction as part of the test procedure. The low amount of biotin we obtain from our diet does not affect these tests however biotin level > 1 mg/ day (Biotin supplements available in the market contains around 10mg of biotin) can result in false positive or false negative test results.

FDA issued a warning to help educate about the possible interaction between high biotin levels in the blood and troponin level ( a biomarker which helps physicians diagnose a heart attack for patients presenting with chest pain). This could be dangerous as a heart attack requires immediate treatment and an early diagnosis could potentially be missed.

My take on this topic

Biotin supplements are not required for the treatment of hair loss.
If you are on long term supplements, remember to mention it to your treating physician especially if you are getting evaluated for hormonal issues, thyroid function or for a chest pain.
Follow the general hair grooming measures available on a post on my instagram feed.
Get the hair loss evaluated by a dermatologist to get to the cause of it as different types of hair loss requires different form of treatment.
Instead of wasting your money on buying these vitamin supplements, spend it on products that have actually proven to work such as minoxidil, or well formulated shampoos and conditioners instead.

Prickly heat : Another nuisance of the summers

Leave a reply

Summer is here is various parts of India!!! Its hot, its humid, we’re sweating and for the unlucky few, the skin is actually itching and pricking.

Stay ahead of the summer…

Miliaria also called “prickly heat”, “sweat rash”, “heat rash” “ñiang shit” (in my mother tongue) is a common dermatological condition occurring mostly in hot, humid summers. Infants ( <1 year) are more susceptible as their sweat glands have not well developed.

But this does not mean adults are spared, it can occur in adults as well, both males and females

So how and why does it occur?

Miliaria is caused due to blockage of the sweat glands ( eccrine glands) which may be due to excessive colonisation of a bacteria in our skin ( don’t worry its mostly the bacteria which normally resides in our skin. Yes! we have bacteria and yeast, a small little world living in out skin :p).

Sometimes these sweat glands can be occluded by debris (i.e dirt)

Sweating is therefore a risk factor, and activities or febrile illness (infection/medical conditions that causes fever) that could increase sweating are high risk factors for developing miliaria.

Source : https://www.ncbi.nlm.nih.gov/books/NBK537176/

Levels of occlusion of the sweat duct and its resulting clinical presentation

Sometimes the duct ruptures causing inflammation around the area, seen clinically as red bumps, itching, pricking sensation.

How does it present?

Occlusion of these sweat glands result in sweat not being able to leave the surface of the skin, & instead gets pushed back into the different layers of the skin forming small sweat filled lesions.

Depending on where the blockage occurs, the presentation can be different clinically.

Miliaria crystallina

Miliaria crystallina : Sweat filled blisters with “Dew drops” appearance
See the resemblance?

Blockage occurs at the superficial part of the skin (epidermis). Presents with these asymptomatic (no itching /pain/burning sensation) clear fluid filled lesions (vesicles) over normal looking skin.They are referred to as “dew drops” .
The fluid collected is actually sweat!!

2. Miliaria rubra

Most common form, presents with multiple red raised lesions (papules). (“Rubra”= Red in Latin). Individuals also experience an uncomfortable pricking/itching sensation in their skin. Pustules (pus filled lesion) may also be present and its referred to “miliaria pustulosa”.

3. Miliaria profunda

Least common form. Mostly seen in individuals who suffer from repeated episodes of miliaria rubra. Seen as large deeper lesions either skin colored or red. May be itchy.

Is this condition dangerous?

Apart from being a nuisance, miliaria normally resolves once the factors causing the sweating is removed.

In very rare occasions when the involvement is extensive or in infants with poorly developed sweat glands, it can be threatening.

Normally, sweating is a defence mechanism to increasing body temperatures, which cools the body down as the sweat evaporates from our skin. As the sweat glands are blocked this process is not able to take place and individuals may then be at risk of hyperthermia.

Signs to look out for:

Fever, muscle cramps, headache, fainting, increase heart rate, dizziness.

How to prevent and treat it?

As the condition is cause by heat and sweating, the main measures are to reduce exposure to such environmental conditions as much as possible.

General measures

Staying indoors in air conditioned , well aerated rooms/offices.
Avoid strenuous exercise which is a potential risk factor.
Wear loose fitting, cotton clothing
Avoid tight fitting clothing ( jeans, jeggings, treggings and all the likes) , un-necessary bandaging as friction can lead of excess distension of the sweat duct causing its rupture.
Avoid wrapping your baby in layers of clothing.
Take frequent showers with cool water and mild pH balanced soaps (such as dove, or other syndet soaps) to help remove debris from the skin. You do not need to use a soap for every bath you take in a day, using a soap once a day is adequate.
Cool compressed with a damp towel helps calms the skin
If you don’t have the luxury of travelling in air conditioned cars/buses, try carrying a face towel with you which you can damp with cold water for regular compressions on your face, chest, neck etc.
Change clothes such as gym wear, uniforms and hop into a cold shower immediately once the activity is over.
Avoid use of occlusive moisturisers/ointments.

Specific treatment options

Powders/Sprays formulated with menthol (for cooling and anti-itch action), anti-bacterial (boric acid), anti-septic (zinc oxide) are easily available in the market. Note that, without the general cooling measures mentioned above, this form of treatment would not be effective on its own.
Seek a dermatologist opinion if the rash gets too uncomfortable, as a course of mild steroid to help reduce the inflammation my be required. ( I stress on the term “mild steroid” as there are various classes of steroids with various potency and we do not want you to be given the wrong form of such creams/ointments as they do come with their own set of complications)
A course of antibiotic cream may be needed if pustules are present and extensive.

Heat rash usually subsides spontaneously even without treatment if the above general cooling measures are followed and treatment is usually un necessary.

Miliaria crystallina, usually subsides within 24 hours of removal of the predisposing factors. And the good news is that miliaria heal without scarring.

featured image: Photo by Hans Reniers on Unsplash

A dermatologist’s take on DIY skincare

Leave a reply

As a dermatologist, I’m a firm believer in evidence based medicine. We study dermatological issues and their treatment options throughout our training. We study molecules used in skin or hair care products religiously, reading the research available on them, which active ingredient works, how they work, the dosage, their benefits and side effects and how effective they can be for a particular condition.

Therefore, I personally do not advised nor can I validate the popular culture of “DIY” (do it yourself) or home remedies for skin or hair care.

Yes, dermatologist keep saying that the basics to skin care are ABC (Vitamin A, Vitamin B, Vitamin C), and many of the active ingredients used in skincare are plant derived, this can be confusing to many of us. One can find the “ABC’s” easily in one’s kitchen, pantry, or garden so why shed your money buying expensive products containing the same?

Let me break it down for you in simple terms:

The skin has three layer, the epidermis (uppermost), the dermis (middle) and the subcutaneous tissue (fat and lowermost). the diagram on the right is the epidermis, which is composed of several layers.

The upper layer of the skin (epidermis) is described as resembling a ***“brick and mortar”*** structure.

The main function of the skin is acting as a barrier, protecting our body from various environmental substances and it does a pretty good job at it too.

This means many of the DIY’s of tomato paste, lemon juice, etc may not even be able to reach the inside of your skin through that “brick wall” to perform the functions you are expecting them to do.

This is why we have well formulated creams, ointments, serums etc because they contain other agents that help deliver the desired active ingredient (be it vitamin A, B or C etc) to cells in the skin.

Secondly, vitamins are present in various forms, for example for vitamin A we have beta carotene, retinol, retinal, and the most active form retinoic acid. Retinoic acid is the one that binds to receptors present in the cells of our skin to bring about beneficial changes such as anti ageing, anti acne etc.

Simply applying a paste of vitamin A rich fruits such as papaya does not achieve the same result, because vitamin A in fruits & vegetables are in the form of beta carotene.

Thirdly, DIY,s could potentially be doing more harm than good. A common example is a condition called “PHYTOPHOTODERMATITIS” where patients develop an irritant dermatitis when the skin is exposed to certain plants/citrus fruits and sunlight.

Patients develop a red rash on areas of exposure, burning sensation and may develop fluid filled lesions as well. The rash would then heal with pigmentation.

Left image is also called “Margarita burn” -phytophotodermatitis due to the limes present in a margarita cocktail followed by sun exposure. Right image– pigmentation left behind when the irritation subsides.

Just because DIY/Home remedies are all natural does not necessarily mean they are completely harmless and safe

Lastly, even though some skin care products use active ingredients such as various forms of vitamin A, B or C, they have been extensively researched in the labs, animal and human studies. Scientists study the active form of these vitamins, the strength at which these ingredients that have been proven to be effective to produce a desired effect (eg: niacinamide- vit B3, strength of at least 4 % works to reduce pigmentation, repair skin barrier, vitamin C of 20% works as an anti-oxidant, anti ageing, salicylic acid of at least 2% helps unclog pores and so on and so forth).

Simply grinding vegetables, or whisking eggs making a paste for your skin, is not going to achieve the same result
How does one know the strength of the vitamin present in that paste?

Yes, Cleopatra may have bathed in milk to maintain a beautiful youthful skin. We now know that milk has lactic acid which helps in exfoliation of the skin, and we have products designed particularly for that now with or without lactic acid, so people wont have to be bathing in milk for a glowing youthful skin.

Photo by ian dooley on Unsplash

The only time dermatologist advised on using ingredients available at home is for coconut oil. We advised coconut oil application for patients with conditions causing dryness of their skin, who are not able to afford regular moisturisers.

Consuming fruits and vegetables provides you with more nutrients that can be beneficial for skin & hair rather than external application of various DIY concoctions of eggs/lemons/mango etc

A taste of Coffee for your skin and hair

Leave a reply

Coffee and tea has become the key to a great day. Majority of us start our day with either a cup of coffee or a cup of tea. Recently there has been a surge in the availability of caffeine based skin and hair care products. There are caffeine based eye creams, coffee scrubs, serums and the lists goes on.

So is there a logical scientific explanation to this trend or is it just false advertising exploiting consumers using the magic term “natural ingredient” for your skin and hair?

I have just completed a three year course in dermatology and I never read or studied these active ingredients during my tenure as a junior resident. This is because we have a huge syllabus to cover most of which are related to medical conditions and we are less focussed on less studied ingredients used in skin care. So when patients asks me their opinion on these caffeine or tea based products, I was not 100% sure if there is actual scientific evidence to back up the claims of these products.

What I found from digging around for studies on caffeine and its role in our skin

Lets take a look at the science behind caffeine based skin care products

Animal studies has shown that caffeine (coffee) consumption was associated with decrease risk of skin cancers (melanomas, basal cell carcinomas, squamous cell carcinomas). Human studies have also confirmed this negative association. People who consume >3 cups of coffee/ day have decrease risk of skin cancers. Caffeine present in tea, chocolates also reduced the risk of skin cancers. Decaffeinated coffee was not found to have similar negative association which means caffeine in coffee is the important active ingredient that could prevent skin malignancies.

An increase in coffee consumption of one cup per day was associated with a 3% reduction in melanoma risk
Another study found that daily intake of coffee ( >6 cups) caused a 30% reduction in the prevalence of non-melanoma skin cancer in Caucasian women

As great as the the results look, merely increasing coffee consumption does not guarantee an absolute protection from skin cancers. Sun protection is still the first line defence against any skin malignancies.

Are topical applications of caffeine based products beneficial to our skin?

For any active ingredient to work when applied topically, the agent has to be able to penetrate the skin barrier. Laboratory studies both in mice and human skin have show that caffeine can effectively penetrate the skin if formulated in an aqueous base or as microspheres. So, if the caffeine based creams, scrubs etc are well formulated, topical application of about 3-5% caffeine can be beneficial to our skin.

Caffeine as anti cellulite

Cellulite also referred to the “orange peel” appearance of the skin which is due to abnormal localised deposition of fat cells which bulge into the dermis (middle layer of skin) and is seen in the buttocks and thighs of mostly females.

Few studies using animal model to study the effectiveness of caffeine for cellulite, showed that daily caffeine gel application combined with ultrasound improved the appearance of the orange peel skin.

Image courtesy

Caffeine gels, creams, scrubs can temporarily help improve the appearance of cellulite by increasing fat breakdown (lipolysis) and improves blood circulation in the skin.

Caffeine for dark circles and puffy eyes.

Caffeine acts as a stimulant, thats why most of us (including me) need a cup of coffee to start the day. Caffeine improves microcirculation (blood flow) in the skin. As the main reason for dark circles is due to increase fragility of the blood vessels in the skin below the eyes which when they break cause haemoglobin to leak into the skin and breaks down forming a pigment. Another important reason for dark circles is poor circulation (blood flow) which results in pooling of deoxygenated blood under the skin giving the area a bluish purplish appearance (note- oxygenated blood is red while deoxygenated blood is bluish in colour). Topical application of caffeine to the under eyes can improve blood flow and help deliver oxygenated blood to the area which makes the skin look more fresh, hydrated, more elastic with less dark circles.

Caffeine also help in the proper lymph drainage in the skin, therefore can reduce collection of tissue fluid in the area as well, thereby helps reduce puffy eyes.

So theoretically caffeine is a great ingredient for tackling dark circle and puffy eyes. But in reality, this is far from true. Studies using human patients did not show significant improvement in the appearance of dark circles. This could be explained by understanding that the reasons behind dark circles are multifactorial, with genetics,stress and facial bone structure also attributing to the cause and caffeine by itself cannot completely reverse the condition.

With that said, caffeine based skin products can help improve the appearance of dark circles and puffy eyes in certain individuals and its important to remember that the results are not permanent.

The ordinary has a serum containing **5% caffeine** and **EGCG** ( active component in green tea, will talk more on this in subsequent posts).

Caffeine for UV protection

Multiple laboratory studies on mice skin have shown that both oral intake and topical application of coffee enhances the apoptosis (death) of UV induced mutated cells which would otherwise divide and cause skin cancers. Therefore if caffeine is incorporated in sunscreens it can provide additional sun protection benefits. Thus stemmed the marketing strategies of “caffeinated sunscreens”.

However detailed well controlled human studies to test this theory is not available yet. A study using 12 human volunteers to test the benefits of addition of caffeine to sunscreens showed that 2.5% caffeinated sunscreens provided a higher spf value than a non caffeinated sunscreens.

Few sunscreens which also contain caffeine as one of the ingredients

Caffeine for hair growth

Angrogenic alopecia (AGA) is a common cause of baldness especially in males. AGA is due to the increase sensitivity of the hair follicles in the scalp to a hormone called dihydrotestosterone-DHT (an active form of testosterone). DHT causes the hair to enter the telogen phase (resting phase) of the hair cycle which eventually causes the hair to become thin and fine and ultimately falls off.

How caffeine helps combat this hair loss?

In vitro studies, have shown that caffeine inhibits the enzyme 5 alpha reductase which is responsible for converting the inactive testosterone to its active form DTH.
As mentioned earlier, caffeine helps improve microcirculation in the skin. This means caffeine application can increase blood flow to the hair follicles which can then receive more nutrients required for hair growth.

Caffeine based hair products in today’s market

A study comparing the effectiveness of 0.2% caffeine liquid lotion to the standard FDA approved antihypertensive drug (drug for lowering blood pressure) – 5% Minoxidil solution in the treatment of androgenic alopecia showed that both were equally effective at the end of a 6 month observation period. This study highlighted the potential of caffeine for treating hair loss.

So would I personally recommend treating your hair loss with some coffee?

I would have to answer NO. I would not recommend caffeine as mono therapy for hair loss.

There are various types of hair loss, and the science behind caffeine for hair loss is stressed on a specific type of hair loss call Androgenetic alopecia (see the pictures above) and even for this condition, not many well controlled human studies are available yet to support the use of caffeine for hair loss. Though dermatologist also see and treat many hair issues, hair loss is one of the commonest reason why patients seek dermatologists consultations. Hair loss could be of various causes, and a proper evaluation about the potential etiology is necessary prior to the start of any treatment.

Many other well documented treatment options are available now for the treatment of hair loss such as Minoxidil lotions, Finasteride, Platelet rich plasma etc. Incorporating caffeine based shampoos could add as an adjunctive therapy to the above.

Take home message

Some of these studies make caffeine look like a star ingredient for your skin and hair. These hair and skin products are based on in vitro (laboratory tests done in well controlled environment which is far from the reality), and few animal studies and well designed human studies are still lacking. So keep this in mind when you buy these products in the market with these huge claims and promises such as “cure for your hair loss” etc.

Note that a certain % of caffeine is necessary to achieve the desired results mentioned above and this has to be formulated in a bases that enables the caffeine to penetrate into the skin. Therefore DIY coffee scrubs, creams may not beneficial to your skin or hair at all as the % of caffeine maybe too less or worst if its too much, unwanted side effects may occur.

In fact, scrubbing your skin with coffee may be too harsh on your skin especially if you have sensitive skin or are using various other active ingredients such as retinoids, glycolic or salicyclic acid etc.

Controversies regarding sunscreens

Leave a reply

This is in continuation the my “All About Sunscreens” post. There are a few controversies relating sunscreens that we are worth mentioning.

1. Does regular use of sunscreens causes deficiency of Vitamin D?

SUNLIGHT IS REQUIRED FOR OUR BODY TO PRODUCE VITAMIN D

Multiple studies have shown that consumers do not use the adequate recommended amount of sunscreen on a daily basis to prevent vitamin D synthesis in our body. Vitamin D can also be obtained from our diet and many fortified food products such as milk fortified with Vitamin D which can compensate for the lack of Vitamin D synthesis via sunlight.

UVB is responsible for Vitamin D synthesis. Adequate amount of Vitamin D can be produced in our body in just under 15 mins of sun exposure to the mid day sun. This process can take longer for darker skinned individuals since they have a natural protection against the sun. Regular daily use of even adequate amount of sunscreens does not lead to Vitamin D deficiency as there are always some parts of our body that are always left unprotected such as our feet or neck or even hands through which UVB can penetrate and initiate the process of vitamin D production in our skin. A recent study showed that:

Regular daily use of adequate amount of sunscreens with high SPF (SPF 50) even in Indian patients with (FST III ,IV) did not cause any vitamin D deficiency in these individuals.

2. Are chemicals used in sunscreens killing our coral reefs?

Few articles were published claiming that chemicals used in sunscreens were toxic to coral reefs and caused bleaching of the reefs. Based on these reports, many beaches in Hawaii and in Florida banned the public use of sunscreens at their beaches. This however was unjustified and potentially risky, exposing beach goers to the increase risks of sunburns and skin cancers.

Several other articles followed debunking this controversy. They highlighted that the earlier reports on the toxic effect of sunscreens on coral reefs were based on experimental studies in laboratories where the reefs placed in plastic bags and were exposed to higher amounts of the chemicals than that present in sunscreen products. This caused bleaching of the reefs. It was then pointed out that the results of these experiments did not translate to real life. The amount of chemicals dispersing from human’s skin into sea water was barely detectable. Since longterm,detailed, well studied scientific evidence regarding this claim is not available yet, banning sunscreens which could prevent skin cancers is unjustified.

It is more important to stress on the fact that rising water temperatures as a result of global warming is more responsible for destroying our coral reefs than sunscreens.

3. Chemical sunscreens are absorbed systemically (into our blood stream) at high concentration. Should we be concerned?

A study published in the Journal of American Association (JAMA) in May 2019 shed new light on the systemic absorption of topically applied sunscreens. The study concluded that active ingredients used in chemical sunscreens such as avobenzone, oxybenzone, octocrylene, ecamsule were all absorbed systemically (into the blood stream) after topical application at significant concentration ( >0.5 ng/ml). According to the Food and Drug Administration (FDA) any ingredient which is absorbed into the system at such concentrations needs further evaluation into the safety and significance of such ingredients in our body. It also means that manufacturers of over the counter sunscreens must produce scientific data on the absorption and safety profile of their sunscreens.

The study concluded that, consumers must not neglect the use of sunscreens that can prevent various types of skin cancers based on this results, since the presence of such chemicals in our blood does not necessarily mean they are toxic or harmful.

For those concerned about this can always opt for mineral (physical) sunscreens.

4. Sunscreens used by adults are not safe for kids?

The incidence of skin cancers are increasing over the years and a unprotected sun exposure during childhood further increases the risks of such cancers in adulthood. Therefore sun protection is especially valuable for children, as it not only decreases the chances of sunburns but also decreases the risks of skin cancers in adulthood.

Regular use of sunscreen during childhood has been estimated to reduce lifetime skin cancer risk by up to 80%

There is no actual difference between sunscreens marketed for adults and for children, nor is it more harmful for children to be using sunscreens formulated for adults. Children are known to have more delicate skin and can be sensitised to various components in the sunscreen products, therefore most sunscreens marketed exclusively for children have less components (fragrance and paraben free) and are mostly mineral based containing zinc or titanium oxide which does not result in sensitisation and allergic reactions.

It is important to note that, the FDA does not approve the use of sunscreens in children less than 6 months of age. Physical sun protection such as wide brim hats, using strollers with proper shade, long sleeves clothing and avoiding exposing babies to sunlight between 10-16:00 hours is the recommended sun protection measures for such age groups.

My personal advice is, if your child is not allergic to any components of the sunscreen and is above 6 months of age, there is no reason to buy a separate sunscreen marketed exclusively for kids.

If you have heard or more controversies regarding sunscreens and want me to discuss about it, drop in a comment below.

All about sunscreens

2 Replies

Sunscreens are the number one skin care product every dermatologist swears by. In the Western countries, where the incidence of sunburns and skin cancers are high among Caucasians, sunscreen is life saving. In a country like India, where the individual’s skin type (FST IV and V) predisposes them to pigmentation disorders (melasma, post inflammatory hyperpigmentation -PIH), sunscreens are the first armour to fight against pigmentation.

Lets recap a little on solar radiation, so as to understand what exactly a sunscreen does.

UVA– 98-99% of the solar radiation reaching the earth’s surface. UVA is the spectrum of UV radiation that can penetrate the dermis and is responsible for immediate tanning, photoaging, pigmentary disorders, photodermatoses such as polymorphous light eruption etc

UVB– 1-2% of UVR reaching the earth’s surface. UVB is highly energetic but does not penetrate beyond the epidermis (superficial layer of skin) and is responsible for sunburns, skin cancers and delayed tanning. UVB is also required for Vitamin D synthesis in our body.

UVC– filtered out by the ozone layer and does not reach the earth’s surface.

How sunscreens work?

There are two types of sunscreen :

Physical or inorganic sunscreens

They contain titanium dioxide, zinc oxide, iron oxide, or calamine, and functions by forming a coat on the skin that reflects, scatter or absorb the UVR. Physical sunscreens are ideal for patients with sensitive skin as the ingredients do not interact with the proteins and lipids in the skin, and they can protect against both UVA and UVB radiation but they bear the disadvantage of leaving a white cast on the skin. The newer physical sunscreens are relatively more expensive as well.

Micronised & ultrafine particles of zinc or titanuim oxide are generally considered more acceptable cosmetically. Multiple positive reviews on elta MD and LRP physical sunscreen, consumers remarked that these sunscreens do not leave white cast and blends easily.

Neutrogena and kiehl’s have mixed reviews. They seems to be well suited for fair skin individuals and not very aesthetically pleasing to individuals with darker skin tone.

Chemical or organic sunscreen

Most sunscreens available in the market are chemical sunscreens. They contain ingredients that can absorb UVR and converts it to heat energy which then dissipates into the environment. They do not leave a white cast on the skin and hence considered more cosmetically acceptable.

Chemical sunscreens are most commonly found in the market. Bioderma photoderm max has a combination of both physical and chemical sunscreen and no white cast on application.

Active ingredients in chemical sunscreens

It is not uncommon to find a mixture of both physical and chemical sunscreen as well. The disadvantage of a chemical sunscreen is that the active ingredients can react with components in the skin such as proteins and lipids which then may result in wanted production of reactive oxygen species causing irritation to the skin. Susceptible individuals may be sensitized to these components in the sunscreen which will manifest as contact allergic dermatitis (red, itchy skin). For this reason physical sunscreens are preferred for patients with sensitive skin.

What does SPF and PA factor mean?

SPF stands for sunburn protection factor which is a measure of protection against UVB induced sunburn. Sunscreen which only mentions SPF means they only provide protection against UVB and not UVA ( the spectrum which is responsible for pigmentation, photoaging). The grading of SPF is as follows:

Low: SPF 2 – 15
Medium: SPF 15 – 30
High: SPF 30 – 50
Highest: SPF >50

An SPF of 15 blocks 93% and an SPF of 30 blocks 95% of the UVB radiation. Note that double the SPF does not mean double the protection. Sunscreens with higher SPF contains more active ingredients which may make the product less pleasing to use to some individuals.

PA factor measures the protection against UVA. It measures the Persistent pigment darkening (PPD) or tanning after UVA exposure.

PA + : some protection from UVA
PA ++: moderate protection
PA +++: best protection
PA ++++: highest protection : rare to find this in products

How to use a sunscreen?

A given sunburn protection factor in a sunscreen can be obtained only when the right amount of sunscreen is used. Studies use 2mg/cm2 when testing for SPF in a sunscreen, however in reality we tend to use a lesser amount which will then result in a lower SPF than what is labelled in the sunscreen. Therefore dermatologist recommend a higher SPF (SPF>30) to help compensate for the inadequate application.

Dermatologist use the “teaspoon rule” to determine the correct amount of sunscreen needed.

3 mL (slightly more than half a teaspoon)- 3 mL for each arm and 3 mL for the face and neck
6 mL (slightly more than a teaspoon)- 6 mL for each leg, 6 mL of the chest and 6 mL for the back

Apply a sunscreen at least 20 mins prior to outdoor exposure so as the ingredients can form a uniform layer on the skin. It is also ideal to wait 20 mins before putting on clothes otherwise a significant amount of sunscreen will be wiped away during the contact with clothing. The best way to do this is to apply a sunscreen right after a shower or washing your face in the morning and not wait until its time you get dressed for work.

When to re-apply a sunscreen?

We are all familiar with the golden rule of “re-application of sunscreens” which states that a sunscreen must be re-applied every 2 hours as physical activities like touching your face, sweating, friction from contact with sand at the beach can remove some amount of sunscreen from your skin. Reapplication is also recommended after activities in water.

So does this rule apply to modern water-resistant sunscreens which can bind effectively to the skin and retains its said SPF even after 40-80 mins immersion in water?? Recent studies have shown that reapplication helps compensate for the under application of sunscreens. Reapplication after 20 mins also provides better protection against sunburn than delayed reapplication i.e after 2 hours. Therefore early reapplication of a sunscreen is preferred, ideally within the first hour of the first application.

Gentle application is better for sunscreens with gel, or creams consistency. Rubbing it immediately on the skin is recommended for spray sunscreens.

Always search for a broad spectrum sunscreen (UVA & UVB protection) and a water resistant sunscreen.

White cast of physical sunscreens.

The white cast blends with the skin in 30-40 secs of gentle rubbing.

Aesthetics of chemical sunscreens

No white cast, no excuse. Wear sunscreen.

Scientific evidence of the effectiveness of sunscreens for melasma in Indian patients.

A recently published study in the Indian journal of dermatology which studied the efficacy of two different sunscreens on skin pigmentation. A total of 230 patients were recruited in the study. One group was given a sunscreen with an SPF of 50 with PA +++ and the other group a sunscreen of SPF 19 and PA +++. At the end of 12 weeks of twice daily usage, a significant improvement in the form of decrease density of pigmentation and better radiance was noted in both groups. The conclusion is that:

Regular use of a sunscreen with high UVA protection (PA+++) highly effective in improving the skin radiance and in decreasing the skin pigmentation.

So my advised is always look for a sunscreen with PA+++ if you have pigmentation issues, and if you are also prone to sunburns, then get one with an SPF of at least 30.

Hope this was helpful. And stay tune to my next posts on “Controversies regarding sunscreens”.

To pee or not to pee? The tale of the Jellyfish sting.

2 Replies

Summer is here and the beach is on our mind! Sunburns and sun safety are not the only things we need to be cautious about. ‘Tis the time to prepare ourselves for another beach health hazard, the dreaded “jellyfish sting”.

Jellyfish are present in all oceans but are more prevalent in warm tropical waters of the Indian and Pacific oceans surrounding Australia. Incidence of jellyfish sting has dramatically increased over the years owing to the influx of thousands of jellyfishes to the sea shore. Scientists believe global warming is responsible for such a trend. Warmer waters provides a favorable habitat for these marine creatures. It has been reported that 150 million jellyfish stings occurs each year. A recent event of a large number jellyfish sting that occurred in Hawaii, reported more than 900 beach goers stunk by Box jellyfish.

The influx of jellyfish into the shores has an effect not only on public health but on tourism as well. (Credit)

Google search for the treatment of jellyfish stings yields various conflicting results such as “peeing on the sting site”, “pouring vinegar”, “rinsing with alcohol”, “ice packs”, etc. So which is the correct first aid method for a jellyfish sting? Before we go into the treatment for a jellyfish sting, lets see how these stings occurs.

How a jellyfish stings you?

Jellyfish are equipped with stinging structures in their tentacles call “Cnidocyte” which discharges nematocyts, a cell containing venom responsible for the ill effects of a jellyfish sting on their prey. Evenomation (discharge of nematocyts) is triggered by mechanical stimuli, fresh water, and other chemical stimuli. The potency of the venom depends on the species of the jellyfish: Box jellyfish and Portugese man of war being the most dangerous types of jellyfish.

This entire process happens in a fraction of a second, making a jellyfish sting the most rapid mechanical event in nature. This is why first aid management of jellyfish sting is very critical.

Symptoms of jellyfish sting

Following a jellyfish sting, symptoms may be immediate or delayed. Stings can occur while you’re in the water or even when the skin comes in contact with a jellyfish washed up to the shore. Immediate symptoms include intense pain, redness, swelling and/or itching at the sting site. Wheals that follow the pattern of the tentacles may also be seen.

Delayed symptoms are similar to any contact dermatitis and therefore are usually diagnosed as a simple contact allergic dermatitis if the history of sea water exposure or visit to the beach is missed. It usually presents 3-5 days later as an erythematous (red), papular, itchy painless rash.

How to treat a jellyfish sting?

Jellyfish stings are mostly reported from beaches in Australia, or The Philippines. During my residency training in Goa, I did encounter a number of jelly fish sting, all of which were local dermatitis and pain, and I never personally encountered a case of anaphylaxis (severe allergic reaction) or fatal cardiac problems because of a jellyfish sting. I remember being asked by my professor about “Portugese man of war”, and I had no idea what this was at that time. Google search on this showed an article on the Times of India reporting sightings of this type of jellyfish in the beaches of Goa in 2018. So yes, though not as common as jellyfish stings in the waters of beaches like Australia or Malaysia, it can still occur in Indian beaches particularly the beaches of Goa.

Lets get down to the treatment part. Since there are thousands of different types of species responsible for the stings with different potency of the venom capable of causing various types of symptoms, there is still no one defined method to treat a jellyfish sting. The good news is that a majority of these stings are mild and self limited (subsides even without treatment).

The main aim of the treatment is to remove the tentacle from the skin and alleviate the pain caused by the venom released by the nematocyst during the sting.

Effective methods (backed up by scientific research)

Sea water soaks or flushing the area with sea water, helps removing the tentacles attached to the skin.

Local application of vinegar (4-6% acetic acid) though a common practice as a first aid method for jellyfish sting in various beaches around the world, laboratory studies have shown that vinegar can potentiate the release of nematocyts from certain multi tentacle species that frequent the waters of Australia. Vinegar is also contraindicated in stings caused by a ceratin species of jelly fish commonly referred to as “Lion’s mane” which are commonly found in the waters of Australia and Norway. Vinegar application is still adopted as a good method to relief pain from such stings in beaches away from Australia where such multi tentacle species are rare. Pouring of vinegar for approximately 30 secs to the affected area still forms the mainstay treatment for box jellyfish sting.

Vinegar provided at the beach as a first aid for jellyfish stings. (Credit)

Vinegar is a good method, for jellyfish stings at beaches other than beaches of Australia and the Norwegian coasts. Always follow treatment protocol of the beach in concern as the type of jellyfish found at different beaches varies.

Mechanical removal of the tentacles using a tweezer or gloved hands can also be done for the tentacles that fail to be removed using sea water or vinegar.

Hot water (45°C) immersion or hot water showers has shown to provide faster pain relieve than ice pack application. Studies have shown that hot water can neutralize the lethal venom of box jellyfish as well.

Local anaesthetic, is indicated if the above measures fail to relief the pain adequately.

Anti venom, produced in sheep to neutralize the venom of the box jellyfish (C. fleckeri ) is also available and is reserved for life threatening reactions such cardiovascular collapse.

Things to avoid

Fresh water, can alter the osmotic pressure which will favor the discharging of the nematocysts.

Urinating on the affected area, is a common mis concept that was even portrayed in the popular series “Friends, when Chandler peed on Monica after she was stunk by a jellyfish at the beach”. Urea, ammonia present in the urine has been shown to cause discharge of nematocysts from the tentacles which can release more venom and increase the pain.

Alcohol (spirits, ethanol), also increases the discharge of the nematocysts.

Mechanical trauma, such as rubbing the area will only stimulate the further release of the nematocysts

Do not rub the stung area while treating it. Gentle immersion or pouring of vinegar are the methods to be adopted

Pressure bandaging is also to be avoided.

Avoid manual removal of the stings using bare hands as secondary stings to the hands may occur.

Preventive measures

It is important to remember that “Prevention is better than cure”.

Avoid hanging out at the beach if there have been local reports of jellyfish sightings. It is important to note that the tentacles of even dead dehydrated jellyfish that has washed up to shore can still release nematocyts with potent venom.

Wearing protective equipment such as full body Lycra suits are advisable for swimmers and divers especially in high risk beaches such as beaches of Australia.

Skin inhibitor cream such as Safe Seaformulated with a water resistant sunscreen are commercially available as Anti jellyfish sting which can prevent the nematocyst from discharging when it comes into contact with human skin.

When to visit the hospital?

For local reaction, such as pain, redness or swelling of the stung site, the above measures are adequate to control the symptoms.

For severe systemic reactions which can present as dizziness, fainting, low or high blood pressure, abdominal pains, difficulty in breathing etc, immediate medical attention is necessary.

It is important to remember that though a common occurrence, jellyfish sting are rarely fatal.

Now that we’re fully prepared for those beach days, lets take a break, step out and enjoy the sun and sand, armed with the knowledge of how to deal with the sting of these marine beauties.

Vitamin C for skin care

5 Replies

When I first read the chapter on “Nutrition in Dermatology” during my course of residency, I came across this quote before the start of the section on Vitamins which grabbed my attention “If less is good, is more better?”

As we all know, vitamins are micronutrients (they are required in small amounts for the normal bodily functioning). With this knowledge, misconceptions of vitamin supplementations sprang up for various health benefits most of which are vague and commercialised for improvement of our general “well being”. The only indication medically for vitamin supplementation is for proven deficiencies of a certain vitamin.

In dermatology, only Vitamin A (retinoid) and Vitamin D are approved by the Food and Drug Administration (FDA) for specific diseases; Vitamin A for acne, psoriasis, cutaneous T cell lymphomas and Vitamin D for psoriasis. I will get into the details of these in later posts.

Let’s go back to the subject at hand: Vitamin C is a water soluble vitamin derived from our diet. Bell peppers, broccoli, spinach, tomatoes, citrus fruits such as oranges, lemons are its richest source. Vitamin C deficiency can cause a condition called “Scurvy” which presents with bleeding gums, fragile skin and hair abnormalities. This use to be a common disease for sailors around the fifteen century, since there were no refrigerators to keep fruits and vegetables fresh during long journey at sea at that time. The famous Portuguese explorer Vasco da Gama, the first European who opened the sea route to India reportedly lost hundreds of his sailors to scurvy.

Can you see any oranges? Neither did the sailors on board this ship.

The recommended daily allowance (RDA) of vitamin C is around 60mg per day and if you’re wondering how much that actually means think of the weight of a single grain of wheat. This can be obtained from both vegetable and fruit we consume daily. So unless you’re not eating your vegetables or fruits you’re unlikely to be deficient in vitamin C.

What research says about the role of Vitamin C in our skin?

From the observation that Vitamin C deficiency can cause fragile skin which would bruise easily with minor trauma and poor wound healing, it was obvious it has a definite role in the normal functioning of the skin.

Vitamin C plays an important part in formation of collagen which is the main structural component of the dermis responsible for the tensile strength of our skin (the ability of the skin to resists breakage under tension). Studies have shown that Vitamin C actively accumulates in the superficial layer of the skin (epidermis) however the level of Vitamin C in the skin does not increase beyond the maximum level reached in the blood; which means supplementing oral vitamin C is unlikely to have any additional effect on the skin.

Vitamin C is an anti oxidant. It helps removes the reactive oxidative species (ROS) from the epidermis (superficial most layer of the skin). These ROS are produced by various biological reactions that occurs in the skin from environmental exposure to Ultra Violet (UV) radiation, pollutants or smoking. ROS are thought to be responsible for accelerating the ageing process evident on the skin as dry, wrinkled skin with loss of elasticity. It has been shown in some studies that the concentration of Vitamin C is lower in ageing skin. The anti oxidant property of Vitamin C has been extensively researched, which led to the emergence of the use of this vitamin as an anti ageing ingredients in your skin care products.

As an antioxidant, it has been shown that Vitamin C can protect against both UVA and UVB induced sun damage. Therefore it has been incorporated in certain sunscreens either alone or with Vitamin E.

Another benefit of Vitamin C is its ability to decrease melanin (brown/black pigment) production by inhibiting the enzyme called tyrosinase required for melanin synthesis. Therefore it has been marketed in skin care products as an “anti blemish” , “glow enhancer”, “glow boosting” must have product for that clear, pigmentation free skin.

With such juicy beneficial effects of vitamin C on the skin, boomed the common practice of applying self made home remedies consisting of various concoctions of lemon or tomato juice in the name of science. This however is the biggest mistakes people make. And yes I was one of those people who would try all sorts of home remedies for my skin. It took me almost 9 years and two degrees to open my eyes to such nonsense. But I did learn from my mistakes. I’m hoping you guys would learn earlier from such posts.

Not only are these home made remedies ineffective, they also have potential side effects. Just because they are obtained naturally and are “chemical free” does not mean it is without any risks. These home made or do it yourself (diy) concoction contains various other components apart from vitamin C. And for some individuals, these may lead to allergic or irritant dermatitis. I’ve seen a patient during my residency walk in to the clinic with red inflamed cheeks after topical application of tomato paste to her face as a “diy face mask”.

“Nothing is more dangerous than incomplete knowledge”
Image source:Photo by Apostolos Vamvouras on Unsplash

Do commercially available Vitamin C products work?

For vitamin C to be able to perform all the above function in the skin, Vitamin C in skin care products has to be carefully and accurately formulated to deliver the active and stable form of Vitamin C at a pH of <3.5 which enables the molecule to be absorbed through the layers of the epidermis (superficial most layer of the skin). The efficacy of a vitamin C product also depends on the concentration, with higher concentration being more effective, the minimum concentration being 8% with a maximum of 20%. Concentration >20% are not more effective and are likely to cause more irritation instead. The entire process can be tricky. Vitamin C is highly unstable and gets easily oxidised on exposure to air which is indicated by the yellow brown discolouration of the product when its completely oxidised. The product will be ineffective at this point. Also as Vitamin C works synergistically with Vitamin E to perform the same function as an antioxidant, most research has been focussed on this combination.

Therefore with such strict parameters to put in mind, the development of Vitamin C for topical use is not an easy or cheap process and not all companies are able to deliver this in their skin care products.

Vitamin C is available commercially as creams, serums, scrubs. Creams contain various other components called vehicle in which the active ingredient and in this case vitamin C is suspended. Vehicles are usually preservatives, and other ingredients which helps in moisturising. The problem with this type of formulation is that the release of the active form of vitamin C that can be absorbed into the skin is uncertain. Also creams, scrubs so not contain adequate concentration of vitamin C. Research has shown that a concentration of at least 8% is required for topical vitamin C to work. Such a concentration are available as serums which are the newest form of skin care product that contain large and adequate amount of the active ingredients with very minimal additional components.

When and how to incorporate Vitamin C to your skin care regimen

Lets recap the benefits of Vitamin C for our skin. First, it protects against UV (UVA and UVB) induced sun damage. Secondly, it acts as an antioxidant and helps in collagen formation which will help reduce signs of ageing. And lastly, it can be use as a depigmenting agent hence beneficial for post acne pigmentation, sunspots, melasma and other pigmentary disorders.

So if you’re looking for something that can perform the above function for your skin, Vitamin C is worth a try. Years of research on topical Vitamin C serum shows that long term daily use of a topical vitamin C serum, does provide great results such as decrease in the number of fine lines, a more even skin tone with decrease in pigmentation.

So when buying a Vitamin C containing product remember that not every product available in the market actually does what it claims.

Do not jump at the sight of “Vitamin C” label, check for the concentration of Vitamin C, preferably go for the one with at least 10% concentration. Always opt for a serum instead of a cream. Research about the company, read the reviews before buying because a legit Vitamin C serum will burn a hole in your pocket.

Vitamin C serums are to be applied daily once in the morning after cleansing your face followed by a moisturiser 5 mins later. The amount will depend on the company’s instruction, usually 3-4 drops is the recommended. But I would advise to start slow, with a lower concentration or fewer drops and work up to the number of drops recommended as it can cause some mild irritation and dryness initially.

Conclusion

Vitamin C like other vitamins are vital for life and are required in very small concentration. Our body receives the perfect amount of vitamins from our diet. So when it comes to vitamins

“Less is definitely good, but more does not equate to better. In fact, more is unnecessary.”

Vitamin C can be beneficial for your skin when applied topically with a correctly formulated products that delivers the right type and amount of Vitamin C and for indications like anti-ageing, photoaged skin where levels of vitamin C in the skin has been shown to be lower than younger skin. Oral Vitamin C supplementation is not indicated except for the treatment of Scurvy (Vitamin C deficiency disorder). And homemade Vitamin C remedies does not deliver the same effect as one expects when reading about the benefits of vitamin C on the skin.

Featured image courtesy:Photo by Noah Buscher on Unsplash

Do we need to fear the sun?

2 Replies

There is nothing like a bright sunny summer day to lighten up your mood. The sun is an essential component in the process of vitamin D synthesis in our skin, required for normal development and functioning of the bones. Yet exposure to the sun is not without any consequences.

Before talking about the risks associated with sun exposure, let’s have a look at the general principles of ultraviolet radiation (UVR) for a better understanding of what we will be discussing next.

The sun emits UVR which is of three different forms depending on the wavelength: UVA, UVB and UVC.

fig. the longer the wavelength of the UVR the deeper the penetration.

Although UVA is less harmful than UVB in its ability to cause cancers, the high amount of UVA that reaches the earth’s atmosphere and the ability of UVA to penetrate deeper into the skin makes protection against UVA it as important as protection against UVB.

How our skin protects us against the harmful UVR?

Besides the ozone layer which absorbs the harmful UVR and preventing it from reaching the earth’s surface, our skin also plays an important role in protecting our body against the UVR.

Our skin acts an effective barrier preventing the penetration of the UVR beyond the dermis (deeper layer of skin) and into the internal organs. Our skin is also equipped with various defence mechanisms such as enzymes and antioxidants which help repair the damage to the cells produced by UV exposure.

But in the process of protecting us from the UVR, certain light absorbing substances (called chromophore) undergoes a photo-chemical reaction that results in damage to the skin cells which results in sunburn, allergic reactions to the sun and if the body fails to repair the damage, the mutations can lead to skin cancers. Therefore the skins bears the maximum detrimental effect of the sun.

So, do we need to fear the sun?

My answer is “YES”, especially if you’re person with Fitzpatrick skin type I-II, who have the maximum risk of UV induced skin cancers (see the previous blog post: “Do you know your skin type?“). Sun protection in these individuals is necessary from a very young age as risk of melanoma (a malignant cancer of the skin) is more with intense intermittent sun exposure from a very young age.

Sun protection is also necessary to prevent early signs of ageing and for individuals with pigmentation disorders or individuals with photodermatosis ( skin diseases caused solely due to the body’s abnormal response to the UVR) or genetic disorders such as xeroderma pigmentosa (inherited disease caused by a mutation that affects the ability of the body to repair the DNA damage produced by the sun).

That being said, fearing the sun does not mean you live under a rock and never see the sunlight again. As I did mention we need the sun for Vitamin D synthesis, and a few minutes of sun exposure two times a week is adequate for this normal process to occur. My advice is for you to understand when and where the danger lies and how to minimise it.

When and where is the sun’s UVR the maximum?

Areas near the equator receives maximum UVR.

fig. the red band represents where earth receives maximum UVR.

Higher the altitude more the UVR (Shimla, Jammu and Kashmir etc), even though these places are relatively colder, sun protection is still a must due to the shorter UVR path.

The time of the day when the sun is directly overhead i.e around noon time (9am- 3pm) is the time when sun protection has to be at its maximum. Early morning and late afternoon sun’s rays are directed at an angle to the earth’s surface and are mostly absorbed.

What if it is cloudy outside?

Clouds can reduce (though not by a great amount) the UVR reaching the earth but in days with scattered clouds, the UVR may even be more as most of the radiation are scattered. So my fellow Meghalayians (people hailing from a state in India call Meghalaya), you still need that sunscreen even if you live in a state whose name literally translates to the “Abode of clouds”

Abode of the Clouds (CC BY 2.0: Rajesh Dutta)

And what if its snowing outside?

Snow and sand, sea, are a good reflector of UVR which can double the risk of UV exposure.

In future posts we will explore the ways of proper sun protections. In the meantime remember that packing a sunscreen for your skiing trip at the Alps is as important as packing your sunscreen for a day at the beach.

Do you know your Skin Type?

2 Replies

Dermatologist used a scale called Fitzpatrick scale or Fitzpatrick skin type (FST) to classify the various types of skin tone based on the response of the skin to ultra-violet radiation (UVR). According to this scale there are 6 skin types.

fig. Fitzpatrick skin types in Westeros.

What determines your skin type?

The skin is composed of several layers of cells. The melanocytes, which are cells present in the epidermis (the superficial layer of the skin), are responsible for the variation in the skin colour of human race. Note that it is not the number of melanocytes but the size of the melanosomes and the type of pigment produced by these cells (also called the activity of the melanocytes) that determine the skin colour of an individual.

One melanocyte is associated with 30-40 (1:36) surrounding keratinocytes, which are the fundamental cells of skins. The keratinocytes engulf the melanosome containing melanin (pigment responsible for skin color) which results in the skin pigmentation.

fig. layers of epidermis showing melanocytes and keratinocytes

Effect of the sun on skin pigmentation

A single exposure to UVR increases the size of the melanocyte with increase in the activity of the enzyme required for melanin synthesis (tyrosinase). Repeated UVR exposure leads to increase in the number of highly active melanosomes as well as increase transfer of melanosomes to the neighbouring keratinocyte which results in tanning (see the little brown dots in the above diagram).

What is the role of tanning?

You can think of tanning as a way the skins naturally defends itself against the oxidative stress produced by the sun exposure. Tanning is physiological protective response to UVR. Melanin acts as a natural antioxidant which quenches the harmful oxidative radicals produced by the chemical reaction which takes place on UV exposure.

Melanin provides a natural sun protection factor (SPF) of 13.4 in black individuals and only 3.4 in pale skin individuals.

Individuals with FST I, II who do not tan with sun exposure are at higher risk of developing skin cancers.

Influence of fashion

The fashion trend influences pale skin individual to desire a darker skin tone which leads them to go through extensive lengths to obtain that “perfect tan” either by prolonged sunbathing at the beach or by artificial tanning machines without considering the risk they impose on their health in the name of “beauty”.

On the other hand darker skin individuals with relatively lesser risk of cutaneous cancers from UVR ironically hide from the sun as society has made them believe that fairer skin is synonymous with beauty.

Fun fact: FST also forms the basis for the variation in skin colour in emojis with FST I & II merged together.

Why do you need to know your skin type?

Knowing your skin type helps you understand the risk of developing skin cancers with UV exposure. Individuals with FST I, II need to strictly adhere to proper sun protection in the form of broad spectrum high SPF sunscreen and protective clothing especially if they are living in tropical countries.

Disorders of pigmentation like melasma, or pigmentation that can occur from either disorders such as acne, or as a complication of procedures such as LASERS, or chemical peels, etc. are more common in individuals with darker skin tone (FST III,IV,V VI). Therefore caution must be taken while carrying out procedures in such individuals.

Consumers must also understand that some studies on the efficacy of certain active ingredients for a particular disorder are performed solely in individuals of lighter skin tone and the same results may not reflect in their skin type. Therefore referring to studies done on individuals of same ethnicity holds more value. For example you should search for studies done on Indian population if you are Indian.