After we confirmed that the results of viral studies for the herpessimplex virus and bacterial and fungal cultures for pathogens were negative,treatment was started with 5% imiquimod cream on a Monday-Wednesday-Fridayschedule. The patient applied the cream at bedtime to the external area ofinvolvement and within the anal canal, washing it off in the morning. Thepatient also applied daily 5% fluorouracil in the morning to the area of cutaneousinvolvement and within the anal canal. Although initially the patient experiencedsome increased irritation, he tolerated the treatment well and continued thetherapy for 16 weeks. Clinically and symptomatically, there was gradual improvementafter approximately 4 weeks of therapy, and at 16 weeks, there was minimalsuperficial ulceration with moderate residual erythema. At approximately 12weeks, the patient showed signs of infection, with increased greenish mucoidmaterial overlying the area of involvement. Cultures showed a mixed bacterialinfection. The patient was treated with 2% topical mupirocin ointment, 0.75%metronidazole cream, and oral levofloxacin, 500 mg, for 10 days with clearingof the infection.