42-Year-Old With Stinging Sensation

A 42-year-old woman presented to urgent care early in the morning saying that she felt a stinging sensation on her arm while she was cleaning her basement the previous day. She thinks it might be a bite but didn’t see anything. She had subsequent marked pain at the site and over the past few hours developed nausea and muscle aches. On physical examination, the patient had a temperature of 101.3°F (38.5°C). There were reddish-brown reticulate patches with intervening pallor and a rim of erythema on the posterior arm.

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