The sun does not cause sunspots

DEAR DR. DONOHUE: What cures sunspots? I have them on my upper chest and back, and my neighbor, a nurse, told me that’s what they are. I’d like to wear a bathing suit, but these spots embarrass me. -- S.S.

DEAR DR. DONOHUE: I swim almost daily in a public swimming pool. My legs are very tan. I have small, white spots on them. Is this a parasite? A worm? How do I get rid of them? -- E.F.

ANSWER: As best as I can determine from your letters, you both have tinea versicolor. It doesn’t come from the sun, from a parasite or from a worm. It comes from a common fungus.

The fungus causes small circles of skin to lose their pigment. Next to tanned skin, the circles stand out like a sore thumb. Adjacent circles can merge to form larger depigmented areas. The upper chest and back, the arms, the legs, the face and the neck are the places usually affected. Oily, excessively sweaty skin encourages growth of the fungus, as do heat and humidity.

The fungus doesn’t lead to ill health. It’s mostly the appearance that causes a patient’s consternation.

The only way to be sure of the diagnosis is to have a doctor scrape involved skin and examine the scrapings with a microscope. The fungus is easily seen.

Selenium sulfide, found in many shampoos, can get rid of the fungus, but a stronger solution than the one found in commercial shampoos is usually required -- 2.5 percent selenium sulfide. Spectazole cream and Nizoral cream also work, as do many other fungal medicines.