Unusual Erythematous and Infiltrated Plaque.

A 30-year-old man presented with an erythematous plaque on his left forearm. The plaque began as vesicles and was pruritic. The area was mildly infiltrated and had a particular pattern (Figure 1). He had applied an ornamental tattoo five days prior to the development of the rash, and the rash did not spread beyond the border of the tattoo. His medical history was unremarkable. Physical examination revealed a raised erythematous lesion with a distinct border. The surrounding skin was normal. The patient was treated with a high-potency topical steroid cream. A hyperpigmented macule persisted for three weeks, but there was no sign of local relapse or neuralgia after six months.