The spots could be signs of either of two skin conditions, one known as vitiligo, the other as tinea versicolor. Vitiligo is a sudden loss of skin pigment that occurs when the pigment- producing cells in one area cease to function. The bleached-out areas appear in all sizes and shapes, commonly on the back of the hands, the arms, the mouth, the nose, the scalp, the site of an injury or an area in which a nerve has been damaged. Excessive sunburn is a possible catalyst, while infection, illness and emotional stress can intensify an existing problem.
While the cause of vitiligo is unknown, there are some popular theories. One argues that the condition is caused by an abnormality in the nerve endings near the pigment cells. Another says the problem develops after the sufferer becomes allergic to his or her own pigment cells, while still another maintains the cause is an imbalance in the body’s immune system, which begins to turn against normal cells.
Tinea versicolor can result from a fungal infection on the skin. It may be present all year round, but it becomes more noticeable in summer when the affected areas remain pale as the surrounding skin tans.
In either case, protect these areas from the sun at all times as they will easily burn, and seek the advice of a doctor or dermatologist.