38-Year-Old With Rash After Heating Pad Use

A 38-year-old woman presented to urgent care for rash that had developed on her trunk 2 months prior. On examination, extensive hyperpigmented, reticulated patches were seen on her back. She had no recent history of sunburn, extensive sun exposure, or history of dermatological conditions. Additional history revealed the use of a heating pad for the preceding 3 months to help manage her chronic back pain. She often rested on the electric heating pad for several hours and sometimes fell asleep with the heating pad on.  

View the image above and consider what your diagnosis and next steps would be. Resolution of the case is described on the following page.