A 55-year old woman presented with a 6-week history of an enlarging, tender, pruritic, 4-cm erythematous patch with central inflammatory papules distributed on the medial forehead (Figure, A). No inciting events, such as arthropod bite or trauma, were noted. She was initially treated for presumed shingles with valacyclovir, cephalexin, gabapentin, and hydrocortisone 2.5% topical ointment with no improvement in appearance or symptoms. No other cutaneous abnormalities were noted. A punch biopsy specimen of the left medial forehead was obtained, and histological and immunohistochemical analyses were performed (Figure, B and C).