Ingredients in some vitamin supplements may cause hives or a skin rash. Treatments include antihistamines and topical corticosteroids.

If over-the-counter antihistamines aren’t effective for you, your doctor may recommend H2 blockers, steroids, biologics, or ...

All the hairs have disappeared from a three-inch long patch on my left arm. The bare patch is half the width of my arm and extends just onto the back of my left hand.