Prickly heat : Another nuisance of the summers

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.

  1. Miliaria crystallina

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”.

Miliaria rubra

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