The cause of polymorphous light eruption is unknown. It usually appears 1 to 2 days following exposure to sunlight and may last up to one week. It is more common during adolescence and young adulthood, and occurs more frequently in females. It appears as recurrent redness (erythematous) and/or blistered patches (plaques). It may be an inherited disease in certain Native American groups.
Review Date 4/16/2019
Updated by: Michael Lehrer, MD, Clinical Associate Professor, Department of Dermatology, University of Pennsylvania Medical Center, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.