Nipple dermatitis is a localized dermatitis of the areola and/or nipple. It is frequently associated with breastfeeding, friction from jogging, and other contact irritants such as soaps, detergents, or chlorine. It is more common in atopic individuals; in fact, nipple eczema is considered a minor diagnostic criterion for atopic dermatitis. It may also be seen in cases of nummular dermatitis. Because nipple dermatitis may mimic Paget disease, if it does not respond to simple therapy with a mild-to-mid-potency topical steroid, a biopsy should be performed.