White patch on skin: A cause for concern?

Several months ago, my son developed a small white patch on the skin of his arm. It appears to be getting larger. Should I be concerned?

- Gena / New York

Answer

Probably not. A small white patch on skin may have several causes. Sometimes a small area of skin becomes irritated or develops mild eczema, which results in a patch of skin that is lighter in pigment than the skin around it (pityriasis alba). This is particularly common in children with allergies, asthma or eczema. Your doctor may recommend applying moisturizer to the affected skin and avoiding harsh or drying soaps.

Another possible cause of a white patch on skin is a superficial yeast infection (tinea versicolor), which may cause the skin to look either lighter or sometimes darker than normal. Treatment of tinea versicolor may include antifungal creams or shampoos.

If the white patch on your son's arm continues to enlarge or if additional white patches appear in other places, your son should be evaluated by a dermatologist. Other skin diseases also may cause light or white patches on the skin, including psoriasis and vitiligo.

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