Posted by a Pediatrics Resident:

A 30-year-old with a history of chronic migraines and erythromelalgia presented with a red rash on their neck. The treating resident asked the Figure 1 community if they thought the diagnosis was a rash or levido reticularis. A number of dermatologists and rheumatologists on Figure 1 diagnosed the patient with erythema ab igne, a skin condition caused by heat exposure, and reminded the treating resident that the condition can be caused by repeated exposure to heating pads used to relax muscles and relieve headaches. The treating resident later confirmed this diagnosis.