A 46-year-old woman presented with an erythematous, scaly eruption that started on her arm and spread to her back, chest, and groin. The rash began 3 months prior and worsened during warmer weather. She denied pain, pruritus, or rash elsewhere. Her medical history included seasonal allergies and hypothyroidism, treated by levothyroxine. Her other medications included multivitamins and fish oil.
Physical examination revealed annular erythematous and scaly plaques with central clearing, coalescing along the chest, back, flanks, and groin (Figure). Examination of the feet revealed scale and maceration between the toes; examination of the hands and legs was unremarkable.
Milam EC, Meehan SA, Ramachandran S. Well-Demarcated, Scaly Plaques. JAMA. 2016;315(5):508-509. doi:10.1001/jama.2015.16068