Polymorphic light eruption is a common reaction to sunlight (ultraviolet light) that occurs in light-sensitive individuals.

Polymorphous light eruption

The cause is unknown. Some experts think it is a type of delayed allergic reaction.

Small red pimples and blisters appear on the skin within 1 - 4 days after exposure to sunlight. The lesions may also appear as scaly skin.

Medium to strong steroid creams or ointments may be prescribed by your doctor. They are used 2 or 3 times a day helps clear the rash. Steroid pills may be used for more severe cases.

Some people benefit from phototherapy. Phototherapy is a medical treatment in which your skin is carefully exposed to ultraviolet light. This may help your skin become sensitized to the sun.

In many patients, the chances of having this condition after being in sunlight decreases over time.

• Use sunscreen. Sun protection with broad spectrum sunblock that works against UVA rays is important.
• Avoid sun exposure during hours of peak sun ray intensity.
• Apply generous amounts of sunscreen with a sun protection factor (SPF) of at least 30. Pay special attention to your face, nose, ears, and shoulders. The higher the SPF, the greater the protection.
• Apply sunscreen 30 minutes prior to sun exposure to allow penetration. Re-apply after swimming and every 2 hours while you are outdoors.
• Wear sun hats. There is also SPF clothing and swimwear available.
• Wear sunglasses with UV protection.
• Use a lip balm with sunscreen.

Lebwohl MG, Heymann WR, Berth-Jones J, Coulson I, eds. Treatment of Skin Disease: Comprehensive Therapeutic Strategies. 3rd ed. Philadelphia, Pa: Saunders Elsevier; 2009.