Heat rash is a skin condition, which is caused by overheating. Heat rash is also known as prickly heat or miliaria and is characterized by red or pink rash. It is mainly found in body areas, which are covered by clothing. The condition develops when blockage of sweat ducts occur and become swollen. This condition leads to discomfort and itching. Heat rash is common in babies but adults who live in hot humid areas also may suffer the condition. In addition, newborns in incubators as well as bedridden patients that have fever may also suffer this condition.
What are the causes of heat rash?
When there is excessive perspiration, the ducts from sweat glands may block and cause sweat to leak to the tissues around. This leads to irritation and redness. A person with this condition feels prickly and experiences a sensation of stinging and this is where the name of the condition is derived.
Instead of the sweat evaporating, it remains trapped beneath the skin, a situation that causes swelling and rash. Although it is not clear why the ducts would be blocked there are certain factors, which are thought to play a role in blocking the ducts. If a person has immature sweat ducts, this may cause the condition.
In hot weather, baby’s sweat ducts can rupture and begin trapping perspiration under the skin. This blockage may occur when infants are also dressed in warm cloths. In addition, children undergoing development and are placed in incubators are also likely to develop the condition. Other aspects, which are thought to cause heat rash, are such as tropical climates.
In hot humid weather, people may produce excess sweat, which is trapped underneath the dermis layer. Intense physical activity such as exercise or hard workouts could also lead to excessive perspiration, which further leads to heat rash. People who frequently dress in certain fabrics that do not allow sweat to evaporate away from the skin may also suffer heat rash. There are also certain medication, which may lead to heat rash especially those that enhance the function of sweat glands like clonidine, opiates and beta-blockers.
Other conditions, which could lead to heat rash, are such as sleeping under and electric blanket or bundling up excessively in times of winter. Products like ointments and creams when heavily applied can block the sweat ducts allowing the sweat to penetrate to surrounding tissues where it is trapped causing irritation and swelling. Patients with high fever may also develop the condition and this is because the fever is likely to trigger excessive sweating.
Heat rash manifests as tiny pimples or dots on the skin. The rash could be irritating especially when a person dresses in clothes, which cannot allow perspiration to occur. Scratching may also lead to secondary infection though rarely. In adult, heat rash is likely to occur in folded skin and in areas where clothing causes friction.
The rash is mainly seen in chest, shoulders and neck and at times, it may occur in groin, elbow creases and armpits. Depending on the areas where sweat ducts are blocked, there are different miliaria conditions, which may occur. Miliaria crystalline is a mild form of heat rash and mainly affects the upper layer of the skin. This condition forms clear fluid-filled bumps or blisters that usually break easily. These bumps are also known as papules. The blisters resulting from miliaria crystalline are not painful or itchy. The condition may affect both newborns and adults and it clears on its own though it may come back if a person is exposed to hot humid weather.
Another form of miliaria is miliaria rubra. This condition occurs deeper in the skin or epidermis. This is also known as prickly heat and can affect adults who live in hot humid conditions or stay in bed rest for a long time. In infants, miliaria rubra develops in the first and third weeks of life. Miliaria rubra signs include red bumps, prickly feeling, itching skin, and lack of sweating in the affected area, a condition known as anhidrosis.
There is also a less common type of miliaria and this is miliaria profunda. This condition affects mainly adults and manifest in the dermis and deep within the skin. People may suffer the condition soon after they have had a physical activity. Signs of miliaria profunda include firm flesh-colored lesions, which may resemble goose bumps.
Treatment of heat rash
Treatment of heat rash is aimed at reducing sweating. Patients can stay in air-conditioned environments or use fans to help circulate air. In addition, people can wear light clothing, which are made of fabric, which allow breathing of the skin. Another way to reduce excessive sweating is by limiting physical activity.
Heat rash tends to clear fast when the skin is cool. Mild heat rash may not require treatment but more severe forms may need the use of tropical therapies to prevent complications. Patients with severe heat rash may use calamine lotion to sooth itching. Anhydrous lanolin may be used to prevent sweat ducts from blockage and stop formation of new lesions. In addition, tropical steroids are applied to minimize itching.
In babies, you may let the skin air-dry rather than using towels. Ointments and lotions may be minimized because they may cause irritation of the skin. Hydrocortisone cream or calamine lotion may be used upon doctor’s approval to treat irritation on babies’ skin.
Pictures of Heat Rash
Here are heat rash images, see how it affects babies and adults.