An Emergency Department Presentation of Erythema Ab Igne Caused by Repeated Heater Exposure.

Erythema ab igne is a rare, reticular erythematous hyperpigmentation resulting from repeated thermal injury. We describe our assessment of a 22-year-old woman with bilateral shin discoloration of 3 weeks' duration. Upon questioning, she revealed that she had been standing near a portable heater for extended periods. She was advised to avoid further exposure to the heat source. By the time of a follow-up clinic visit, the discoloration had resolved. Patients with hyperpigmented patches should be questioned about heat exposure. Erythema ab igne can progress to serious dermatologic conditions, but if the cause is eliminated, it usually resolves without medical intervention.