Erosive perianal lichen planus responsive to tacrolimus

A 46‐year‐old man presented with bleeding and painful sores around the anus of 2–3 years’ duration. The lesions had improved with a course of oral antimicrobials prescribed by a surgeon, who had performed a biopsy reported as showing nonspecific changes. Topical corticosteroids had also led to improvement, accompanied by the development of painful “pimples.” The patient had a history of recurrent oral herpes simplex, but denied other medical problems, persistent oral lesions, or human immunodeficiency virus risk factors.  A total body skin examination revealed two shallow ulcerations of the perianal mucosa with minimal background erythema. No other cutaneous or mucosal lesions were noted. The remainder of the examination was unremarkable. A viral culture was negative, and there was no response to a 5‐day course of oral antiviral therapy (500 mg of valacyclovir twice daily). After avoiding topical therapies for 10 days, a lacy white discoloration was noted ( Fig. 1). Review of the original biopsy specimen showed a band‐like lymphocytic infiltrate in the papillary dermis with involvement of the basal layer, consistent with lichen planus. 1Lacy white discoloration and erosions of the perianal mucosa The patient began a course of topical halobetasol ointment therapy, complicated by folliculitis, which was treated with topical clindamycin lotion. After 10 weeks, the area had completely healed ( Fig. 2) and the patient discontinued topical therapy. One year later, the patient had a recurrence of erosions in the same location. Wishing to avoid the complications of high potency topical corticosteroid therapy, the patient chose therapy with the commercially available formulation of tacrolimus 0.1% ointment. One month later he called to report complete clearing and was tapered off therapy. 2Normal mucosa after treatment with halobetasol ointment