Some people experience a form of body acne known as acne mechanica -- a form of acne triggered by heat, pressure or friction on the skin. Although anyone can get acne mechanica, it is more common among young athletes and solders. These groups often encounter higher-than-normal body temperatures and wear equipment and tight uniforms which make them more likely to develop acne mechanica.
The appearance of body acne can vary: from small bumps called comedones to large, inflamed papules and/or pustules.
Among the many items that can cause acne mechanica are:
motorcycle helmet straps
pads (football, hockey, lacrosse)
tight-fitting synthetic clothing (e.g., bra straps)
The best way to prevent the onset of acne mechanica is to wear a cotton t-shirt to absorb sweat and reduce friction. Athletes should also shower immediately after working out, taking care to wash the chest, back and buttocks with a benzoyl peroxide soap or wash.
To treat acne mechanica, apply a topical acne medication formulated with either benzoyl peroxide or salicylic acid.