By Whoareublesseen. Friday, March 30, 2012 1:39:39 AM
The skin's job is to protect the inside of the body from the outside world, and acts as a preventive barrier against intruders (for example, infection, chemicals, or ultraviolet light). It also plays an important role in the body's temperature control. One way that the body cools itself is by sweating, and allowing that sweat or perspiration to evaporate. Sweat is manufactured in sweat glands that line the entire body (except for a few small spots like fingers, toenails, and the ear canal).
Sweat glands are located in the dermis or deep layer of the skin, and are regulated by the temperature control centers in the brain. Sweat from the gland gets to the surface of the skin by a duct.
A heat rash occurs when sweat ducts become clogged and the sweat can't get to the surface of the skin. Instead, it becomes trapped beneath the skin's surface causing a mild inflammation or rash.
Heat rash is also called prickly heat or miliaria.
Picture of the layers of the skin including the sweat glands
What are the causes of heat rash?
It is uncertain why some people get heat rashes and others don't.
The sweat gland ducts can get blocked if excessive sweating occurs, and that sweat is not allowed to evaporate from a specific area. Some examples of how blockage may occur include the following:
* Creases in the skin like the neck, armpit, or groin have skin touching adjacent skin, which makes it difficult for air to circulate, preventing sweat evaporation.
* Tight clothing that prevents sweat evaporation.
* Bundling up in heavy clothing or sheets. This may occur when a person tries to keep warm in wintertime or when chilled because of an illness and fever.
* Heavy creams or lotions can clog sweat ducts.
Babies have immature sweat glands that aren't able to get rid of all the sweat they produce, which can cause a heat rash if they are exposed to warm weather, are overdressed, excessively bundled, or have a fever.
Heat rash may occur as a side effect of some medications (for example, isotretinoin [Accutane] or clonidine [Catapres].
Who is at risk for heat rash?
Newborns, infants, and the elderly are at risk for developing heat rash. They are especially at risk if they are immobile for long periods of time and parts of the skin aren't exposed to circulating air, which results in the inability of the sweat ducts to "breathe" (evaporative cooling).
Heat rashes are more common in places with hot, humid, climates because people sweat more.
Intense exercise associated with lots of sweating may cause a heat rash, especially if the clothing worn does not allow adequate air circulation.
How is heat rash diagnosed?
The diagnosis of heat rash or prickly heat is made by physical examination. Knowing that the rash appears during sweating or heat, appreciating the location on the body (in skin creases or where clothes fit tightly) and seeing what the rash looks like is enough to make the diagnosis. As with many rashes, the health care practitioner can look at the involved skin and make the diagnosis.
What is the treatment for heat rash?
Home remedies for heat rash
Heat rash often resolves on its own when the skin cools. If the prickly sensation persists, calamine lotion may be helpful. Some clinicians also recommend over-the-counter hydrocortisone creams or sprays.
Some people suggest that vitamin A or vitamin C creams may be effective to treat heat rash, and though there is no evidence that they work, there is little harm in these treatments.
Medical treatment for heat rash
Heat rash or prickly heat resolves on its own once the skin cools, but on occasion the sweat glands can become infected. The signs of infection include pain, increased swelling, and redness that does not resolve. Pustules may form at the site of the rash. This infection occurs because bacteria have invaded the blocked sweat gland. Antibiotic treatment may be required. Chronic and recurrent heat rash may need to be treated by a health care practitioner or dermatologist (skin specialist).
How can heat rash be prevented?
Prevention is the most important treatment for heat rash. By allowing the skin to be exposed to circulating air, the potential for sweat glands to become inflamed decreases.
Other strategies to prevent heat rash include:
* avoid exercising in hot, humid weather,
* wear loose clothing made of breathable fabrics like cotton,
* use air conditioning, and
* keep the skin clean with frequent baths or showers to prevent sweat glands from becoming clogged.