A 67-year-old heterosexual Chinese man presented with a 1-year history of a persistent painful ulceration on the perianal area (Figure 1). He had been treated with topical and oral antiviral agents for a presumed herpes simplex viral infection, without improvement. He also had a 13-year history of central diabetes insipidus and had been treated with nasal desmopressin acetate. On physical examination, multiple well-defined, punched-out ulcers were noted around the anus and in the perineum, without involvement of anal mucosa. There was no lymphadenopathy in the groin. Cultures were negative for viruses, fungi, and acid-fast bacilli. The results of a complete blood cell count, a differential cell count, chest and whole-body bone radiography, abdominal sonography, and enhanced computed tomography of the brain, with thin-slice sections of the sella tursica, were unremarkable.
Tzung T, Wu J. Nonhealing Perianal Ulcers—Quiz Case. Arch Dermatol. 2005;141(9):1161-1166. doi:10.1001/archderm.141.9.1161-c