Polymorphic light eruption is a common skin reaction in persons who are sensitive to sunlight (ultraviolet light).
The cause is unknown. Doctors think it is a type of delayed allergic reaction.
Small red pimples and blisters appear on the skin within 1 to 4 days after exposure to sunlight. The lesions may also appear as scaly skin.
Steroid creams or ointments may be prescribed by your health care provider. They are used 2 or 3 times a day. Steroid pills may be used for more severe cases.
Phototherapy may also be prescribed. Phototherapy is a medical treatment in which your skin is carefully exposed to ultraviolet light. This may help your skin become used to (sensitized to) the sun.
Many persons become less sensitive to sunlight over time.
- Avoid sun exposure during hours of peak sun ray intensity.
- Use sunscreen. Sun protection with broad spectrum sunblock that works against UVA rays is important.
- 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 before sun exposure so that it has time to penetrate the skin. Re-apply after swimming and every 2 hours while you are outdoors.
- Wear sun hats.
- Wear sunglasses with UV protection.
- Use a lip balm with sunscreen.
Polymorphous light eruption
Update Date 5/13/2013
Updated by: Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.