Intensely Pruritic Rash After Sun Exposure in a Tween Girl

July 17, 2015

What are the characteristics of this blistering rash caused by exposure to UV light?

This intensely itchy, blistering rash on the forearms and upper chest of a 13-year-old girl occurred after a day at the beach. The girl had polymorphic light eruption (PMLE), the most common abnormal reaction to UV light.

All of the following statements about PMLE are true, except: