For three months, a 38-year-old man has been trying to resolve an “eruption” on his neck. The rash burns and itches, though only mildly, and produces clear fluid. His primary care provider initially prescribed acyclovir, then valacyclovir; neither helped. Subsequent courses of oral antibiotics (cephalexin 500 mg qid for three weeks, then ciprofloxacin 500 mg bid for two weeks) also had no beneficial effect. There is no family history of similar outbreaks. The patient, however, has had several of these eruptions—on the face as well as the neck—since his 20s. They typically last two to four weeks, then disappear completely for months or years. The eruptions tend to occur in the summer. He denies any history of cold sores and does not recall any premonitory symptoms prior to this eruption. He further denies any history of atopy or immunosuppression. His health is otherwise excellent, and he is taking no prescription medications. The denuded area measures about 8 x 4 cm, from his nuchal scalp down to the C6 area of the posterior neck. Discrete ruptured vesicles are seen on the periphery of the site. A layer of peeling skin, resembling wet toilet tissue, covers the partially denuded central portion, at the base of which is distinctly erythematous underlying raw tissue. There is no erythema surrounding the lesion, and no nodes are palpable in the area. A 4-mm punch biopsy is performed, with a sample taken from the periphery of the lesion and submitted for routine handling. It shows a hyperplastic epithelium, as well as intradermal and suprabasilar acantholysis extending focally into the spinous layer.
