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Heat Rash or Prickly Heat

Heat rash is a condition in which red tiny spots appear on skin. It is usually seen when intensity of heat increases resulting in excess of sweat production and blockage of sweat gland followed by itching and redness.


When summer arrives, along with it also brings hot, humid weather. Due to increase in temperature we tend to sweat a lot as well as to avoid sun tan or sun burn we try to cover our body parts with layers of clothes. As a result, our sweat ducts sometimes get blocked and also swell. Consequently, red or pink rashes start developing in area covered by clothes which causes lots of discomforts and itching. These small bumps are known as heat rash and even sometimes appear as blisters. There are different types of heat rash on one of them is also known as prickly heat which occurs very commonly and thus heat rash is very commonly also referred as prickly heat. It develops when an individual is dressed too much warmly irrespective of weather, as well as also seen in case of adults during hot, humid weather.

Heat Rash Symptoms

Heat rash or prickly heat can occur anywhere in body but usually seen on back, chest, neck, thighs, sometimes on face, under the arms, under the breasts, elbows etc. On the skin surface when friction gets created, heat rash develops. They appear as small red or pink spots and the surrounding area becomes red and on close examination, it may also show mild swelling. These spots so formed cause lots of discomfort as irritating skin causes constant itching and prickling sensation. They are usually harmless. Irritation so developed is due to the rubbing of clothes over heat rash or even by scratching them. In some cases, excess of irritation may give rise to secondary skin infection.

Causes of Heat Rash

During summer, an individual sweats profusely. Sweat produced should get on the surface of the skin. This will facilitate evaporation and this is body's natural mechanism to cool down. However, sometimes these sweat glands get blocked and as a result sweat that is produced gets trapped underneath skin. This causes formation of tiny red bumps and inflammation of surrounding area. This is known as heat rash or prickly heat. It usually occurs on covered areas of the body and areas which are not covered only develops heat rash if an individual sweats profusely from those areas.

Individuals at Risk of Heat Rash

Heat rash is a very common discomfort faced almost by everyone during summers. However, certain individuals are at high risk of facing it like the ones wearing too much layers of clothes and also synthetic clothing rather than wearing cotton fabrics. It is not necessary that heat rash only occurs in summers. Even it may be seen in winters, in case of individuals who sweat profusely but wear too much of clothing and do not allow their skin to breathe properly. Too much exposure to heat, sun or fire can also lead to formation of heat rash. Individuals who are suffering from illness or due to some reason are immobile and thus they have to spend most of their times in bed are also at high risk, particularly if they are using warm bedding. All those individuals who sweat a lot are at very high risk and profuse sweating may be due to some illness or may be due to over weight. Also, babies are also at high risk of suffering form prickly heat. This is because in their case sweat glands do not get fully developed as well as they are dressed up in too much clothing most of the times. Individuals who do intense exercises with improper clothing which does not facilitate proper air circulation also develops severe heat rash. Individuals who use heavy creams or lotions in summers which contain excess amount of oil will become prone to occurrence of heat rash as their sweat glands will get blocked due to oil present in these products. Some medicines like clonidine exerts side-effects like heat rash and individuals who regularly take these medicines are at high risk of developing it.

Diagnosis of Heat Rash

Since heat rash is a very common discomfort, it usually do not require any special medical diagnosis. An individual itself can diagnose it by its appearance as well as symptoms. Usually it disappears within 3 to 4 days, however if it does not and symptoms if are seen getting more worse then medical diagnosis and treatment should be taken. Sometimes, it may get infected and in this case medical diagnosis is essential. Look for the signs of infection like the affected area which was a little red, if starts showing increased redness or swelling then it is a sure sign of infection. Infected area will show increase in both temperature and pain. Sometimes pus is seen coming out of these heat rashes. Extension of red streaks from affected area is another sign and lastly an individual will also display high fever and chills.

Types of Heat Rash

There are different types of heat rash differing from one another in appearance as well as severity. Miliaria crystallina is commonly occurring heat rash and when it comes to severity, it is mildest of all. It appears as small bumps which may be clear or filled with white fluid, often bursting own their own. It is more commonly seen in babies and as it is mild in severity, it does not cause itching and is rarely painful. Prickly heat or miliaria rubra is very commonly seen in adults and relatively less in babies and children. It causes red bumps, itching, swelling, redness, inflammation and occurs quite deep in epidermis. Sometimes, it does get filled with pus and then it is called as miliaria pustulosa. There is another rare type of heat rash that develops which is known as miliaria profunda occurring in dermis. Large, flesh-colored bumps appear and usually occurs due to intense physical activity which leads to excess of sweat production.

Treatment of Heat Rash

Heat rash disappears itself in 3-4 days and the resulting symptoms so caused like bumps, inflammation, itchy skin, redness, irritation all seem to disappear. If it does not disappear then it is better to seek medical help and check with doctor as soon as possible, especially if the conditions are seen to be further worsening. We can follow few steps or precautions which will help in healing of heat rash. Wear loose light weight and breathable fabric which facilitates evaporation well. Avoid heavy consistency creams or lotions containing lots of oil as they tend to block sweat glands. After bathing or washing of face let the skin dry on its own instead of using towels. This will avoid friction which is created by rubbing of towel on affected area and also reduce risk of infection. Affected area should be kept cool as well as dry. Frequent cool showers or bath will help body to remain cool. Preferably, stay in air-conditioned room or else under the fan. If one cannot avoid going out in sun then try as much as possible to spend most of the time in shade or else in cool area and also carry small fan which will keep body temperature normal. Drink plenty of water and other fluids to bring down body temperature. To treat affected skin, calamine lotion and hydrocortisone creams can be applied. Antihistamine tablets intake will help in heat rash but only take it under prescription of doctor. Prickly heat powders are available in market which will not only keep affected skin dry but also provide some cooling effect. Cold compress if desired for 15-20 minutes can be applied on body to bring down the temperature. Most important rule in never to scratch heat rash. If sweat glands have become infected then doctor may prescribe certain antibiotics.

Prevention of Heat Rash

Prevention is always better than cure. If we follow certain precautions then we can completely avoid all the pain going through it. We need to avoid blockage of sweat glands and allow our body to come in contact with air so that sweat produced by it gets evaporated easily. For this, we need to remain in cool temperature like under a fan, shade or use air-conditioning. Avoid going out in sun or working near heat as much as possible. Exercise should not be very intense during summers and especially should be avoided under the sun. Wear light and breathable fabrics like cotton. Take frequent cool water baths and apply cold compress. Dress up in as few layers as possible. Skin should always be kept cool and dry, especially while sleeping. Do not wear very tight clothes that prevent breathing of skin. Do not use lotions or thick creams during summers. See that soaps used are not drying out skin. Avoid going out in sun and if it becomes necessary then try to remain in cool place and also carry portable small fan. Hydrate body enough so that dehydration do not take place and body always maintains its temperature well.

Prognosis of Heat Rash

Heat rash is self-limiting. It appears when the conditions are made worse like body sweating profusely and sweat glands getting blocked. These favorable conditions for heat rash help it to recur as soon as summers arrive. However, conditions when made unfavorable, it also seems to disappear. As soon as skin is kept dry, cool and is allowed to breathe, it disappears. To obtain best prognosis for heat rash, it is essential to always keep skin cool and dry by taking as many precautions as possible as well as by not allowing sweat to accumulate in body parts.


Heat rash is a term used to describe tiny bumps which may be clear and sometimes may be filled with some fluid. It erupts on the body parts especially on those which are often covered by layers of clothes. Heat rash as the term itself describes appear in summers when intensity of heat is at its highest level. However, in some cases it may appear in any season since heat is the main necessity here for the occurrence of such rashes. Individuals who dress up in too many layers in winters too may suffer from it as they are not allowing their body to breathe properly. Also, individuals who work near heat may get affected by it or else an individual on a trekking or hiking trip may get it due to too much exposure to sun as the main reason for its occurrence is heat and second reason is blockage of sweat glands. Thus, when summers arrive we have to start taking various precautions right from beginning so that we do not have to face all the pain and discomfort caused by it. If for some reason, heat rash has already developed then instead of scratching affected area for relieving itching, we should try to cool down our body temperature and keep skin of our body as much cool and as much dry as possible. We need to allow the skin to breathe properly to treat heat rash as well as to prevent its occurrence.


Author: Juana11 Mar 2017 Member Level: Diamond   Points : 6

With summer just around the corner, the tips provided by the author will surely help people combat the highly troublesome rash.
There are few other remedies for prickly heat or summer rash that are as effective –
• Cold compress using rose water. Soak pieces of cotton or hand towels in rose water and leave them in the fridge (preferably in the freezer) to cool. Applying them on affected area brings relief from the persistent feeling to itch, soothes the burning sensation as well as hastens healing
• A paste made from sandalwood paste and rose water has the same effect as plain rose water.
• Wash a big bunch of fresh Neem leaves and boil in water. Cool and use for washing affected area. Neem has exceptional antibacterial properties and is extremely beneficial for all types of skin ailments.
• Apply ‘Suthol' just after a bath and on clean skin, before stepping out in the sun. Suthol is a commercially available product from the makers of Boroline. It effectively prevents prickly heat. I swear by this product.

Author: Reena Upadhya11 Mar 2017 Member Level: Diamond   Points : 0

Thanks Juana for all the easy remedies for heat rash. Follow them right from beginning of summers and don't wait for the heat rash to develop. This will prevent heat rash or prickly heat from occurrence.

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