Running pays major dividends for your cardiovascular health, but all that sweating and friction can lead to a variety of rashes and skin conditions. Some arise from an overactive immune system or sweat glands, while others come from tiny invaders in your body. Choosing appropriate running gear, keeping cool and showering after your running sessions ameliorates the worst of your rash risk.
Physical exertion of any sort can cause an allergic reaction in some people. You may have cholinergic urticaria -- in layman's terms, exercise hives -- if you find that running causes your skin to break out in flat, itchy welts and redness within a few minutes of beginning your run. Allergies occur when your immune system alerts your body's defense mechanisms too readily. In the case of exercise-induced hives, your own sweat triggers itching and swelling. You're likelier to develop exercise-induced hives if you have other allergies. Your doctor can prescribe a course of treatment for you and help you enjoy your run in comfort.
Tiny flat or raised red dots that feel like hugging a cactus probably means you have a case of heat rash. You might also know this condition as sweat rash or prickly heat. It happens when your body's eccrene sweat glands can't release their cargo of sweat quickly enough. That happens when sweat glands become compressed or skin becomes swollen due to friction. If you have larger thighs, you probably experience heat rash where your legs come into contact with each other as you run. Tight clothing also leads to heat rash. Restrictive waistbands or sleeves form a lid over your sweat glands and cause this itchy rash. Solve the problem with loose clothing that readily absorbs moisture. Pat a little cornstarch powder or use a zinc oxide diaper-rash ointment on areas where your skin rubs together as you run.
Acne doesn't happen because you sweat, but sweat can worsen acne, especially on your back and chest where your damp clothes cling. When a follicle becomes clogged and bacteria move in, a pimple forms; multiple pimples constitute a case of acne. Bacteria thrive in warm, moist environments, and when you work up a sweat during your run, your skin becomes more hospitable to acne bacteria. Change out of damp clothes and shower right after your run to give bacteria a cold shoulder. See your doctor if you experience moderate or severe acne.
Athlete's foot got its name for good reason. While anyone can get this fungal skin infection, the conditions that foster it -- enclosed shoes, damp feet and minor toenail injuries -- are most common in athletes. If you notice an itching, burning rash on one or both of your feet, chances are good it's a case of athlete's foot. Reduce your chances of developing athlete's foot by changing your socks every time you run and keeping your feet as dry as possible. Over-the-counter treatments typically take care of this uncomfortable problem, but see your doctor if your case doesn't clear up quickly with self-care.
Dermatologists refer to any rash that happens when you've encountered a skin irritant as contact dermatitis. If you're allergic to a new fragrance, laundry detergent or soap, you might not notice it under normal circumstances. When you run and sweat, though, the excess heat your body puts out can combine with these potential allergens to give you an itchy red rash. Encountering poison ivy on your run or using a new sunscreen could also cause contact dermatitis. Most cases disappear within hours of removing the irritant.