Heat rash, also known by the name prickly heat, summer rash, or wildfire rash, is common and can be very uncomfortable to deal with.
The medical term for heat rash is miliaria. It happens when sweat gets trapped due to a blockage in sweat glands in the deeper layers of the skin.
Inflammation, redness, and blister-like lesions can be the outcome. Sometimes, an infection can also develop.
People who are overweight and people who sweat easily are very much likely to get prickly heat. Also, babies and children are more prone to rash as their sweat glands are still developing.
Symptoms of heat rash
- small bumps or spots, called papules.
- an itching or prickling sensation
- mild swelling
- On white skin, spots are red.
On darker skin, they can be hard to see, but if a doctor uses dermoscopy — a form of lighted microscope for skin examination — the spots may show up as white globules under the skin with darker halos around them.
Heat rash often impacts areas where excessive sweating is likely more, including the:
- under the breasts
- under the scrotum
- skin folds and areas where the skin gets rubbed with clothing
If bacteria enter the clogged sweat glands, it can cause inflammation and infection.
Treatment for Heat Rash in Summer
Heat rash usually goes away on its own within around 24 hours.
To resolve it, move to a cooler area with low humidity, if possible, and remove any clothing and other things that may increase sweating.
Other tips include:
- Wear light and loose cotton clothing.
- When exercising, select a cool place or a cooler time of the day.
- Use showers, fans, and air conditioning to lower the body’s temperature.
- Avoid any irritants like synthetic fabrics that make symptoms worse.
- Avoid staying in wet clothes.
- Apply a cool compress to the rash for about 20 minutes at a time.
- Use light bedding.
- Drink plenty of fluids, especially water.
- If the rash is itchy, tap or pat it rather than scratching it.
Some OTC preparations can help soothe and resolve continuous heat rash. They include:
Topical preparations — such as calamine, menthol, and camphor-based creams or ointments which can help calm the itching. Use an emollient with calamine, however, as it can even dry the skin.
Steroid creams can minimise itching and inflammation in people aged above 10 years.
Antibacterial products can help manage or prevent the infection.
Causes of heat rash
Heat rash, or miliaria, usually happens when sweat gland ducts get blocked.
This may be due to:
- sweat glands still developing, as in the case of newborns
- a hot and humid environment
- physical activity
- a fever
- wearing tight synthetic fabrics
- wearing a nonporous bandage
- prolonged bed rest
- the use of certain medications, especially those that reduce sweating
- radiation therapy
- certain health conditions, such as toxic epidermal necrolysis
When to see a doctor?
Heat rash usually gets disappears without any treatment. However, see a professional doctor provider if:
- the rash persists for longer or becomes more severe
- signs of an infection, like open blisters or pustular lesions
- signs of heat exhaustion
- Many illnesses cause rashes, which may appear very similar to heat rash. A doctor can get to know the underlying cause
Heat rashes are not usually dangerous, but if symptoms last longer than a few days or symptoms of infection appear, see a professional healthcare provider.
They will closely examine the rash, possibly using dermoscopy for a better inspection.
If required, they may also take a skin punch biopsy or use imaging technology to know the better reason for the rash.
Certain changes in the skin are a common symptom of many conditions. Heat rash can also sometimes resemble other health issues, like:
- viral infections, like chickenpox or measles
- bacterial infections, such as impetigo
- fungal skin infections, such as candidiasis
- insect bites
- folliculitis, due to clogged hair follicles
- acute HIV
- a response to HIV treatment
If any of the following symptoms occur, they may indicate the reason for the rash is more serious:
- a fever
- a cough
- a runny nose
- enlarged lymph nodes
- muscle aches
To lower the risk of heat rash, try to:
- Avoid locations or activities that increase sweating.
- Use a fan or air conditioner if possible.
- Wearing light clothing made of natural fibres, like cotton.
- Minimise exposure to hot and humid weather conditions.
- Gently exfoliate the skin to get rid of dead skin cells and sebum that may clog the sweat glands.
- Take frequent cool showers and be sure to pat the skin dry properly.
Heat rash is generally very common, especially among babies and anyone in hot, humid climate conditions.
It usually goes away on its own without any treatment, although home remedies can even help to ease the rash and relieve any discomfort.
If heat rash appears to be involved deeper layers of skin, if there are certain signs of infection, such as blisters, or if it is lasting for more than a few days, seek medical attention.
Many health conditions can cause rashes that resemble heat rash, so if a person has other symptoms, such as a fever, it is vital to get a diagnosis.