A rash on your arms after exercise can be caused by miliaria or cholinergic urticaria -- both occur as a result of sweating because of a rise in body temperature. If you experience a rash in combination with fever, swollen lymph nodes or severe pain, always consult with your doctor before attempting to treat your symptoms at home.
There are three levels of heat rash which range from mild to more severe and they consist of miliaria crystallina, miliaria rubra and miliaria profunda. Miliaria crystallina is not itchy and only results in small bumps on the top layer of your skin. Miliaria rubra affects the epidermis and has a prickly sensation accompanied by small red bumps. Miliaria profunda is the most severe and affects the dermis layer of skin and resembles goose bumps. The arms are one of the most common areas for cholinergic urticaria and these hives appear as small red wheals that itch and burn.
Heat rash is caused by your sweat ducts becoming clogged which results in perspiration being trapped under your skin. Areas where your skin creases tend to be affected the most by heat rash after exercising, such as your arm pits and elbows. Your risk of heat rash increases if you exercise in hot-humid climates while wearing tight clothes or clothes that restrict perspiration from evaporating normally. Creams, ointments and powders can also clog your sweat ducts resulting in heat rash. Cholinergic urticaria is an inflammatory response that is caused by sweating which results in specific immune system antibodies reacting to certain antigens. Exercise is a common cause of cholinergic urticaria.
Miliaria will usually disappear on its own within seven to 10 days. If the rash is still present after 10 days or does not appear to be getting better, consult with your doctor. Calamine lotion can relieve itching associated with miliaria, but in more severe cases, a topical steroid can be used. tay cool and wear lightweight clothing while treating a heat rash. Cholinergic urticaria typically disappears within an hour of cooling down. Oral antihistamines and beta blockers have shown to be effective at treating cholinergic urticaria.
Anhydrous can prevent your sweat ducts from becoming blocked, so you lower your risk of heat rash after exercising. You can prevent heat rash and cholinergic urticaria by keeping your body temperature low so you can reduce your amount of sweating. Exercise in an air-conditioned area or in front of fans to stay cool. Wear loose cotton clothing while exercising and dress appropriately for the weather. Avoid wearing creams, ointments and powders while exercising.
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