Because syphilis and LGV had been ruled out, doxycycline was discontinued and a regimen of valacyclovir 1 g every 8 hours for 3 weeks was started. The patient had a remarkable response to the antiviral agent. At his clinic follow-up 10 weeks after the completion of antiviral therapy, his symptoms had completely resolved. A sigmoidoscopy performed approximately 3 months after antiviral treatment ended revealed normal rectal mucosa and no evidence of masses. A biopsy performed at the time of the sigmoidoscopy did not show any histopathologic features consistent with HSV. Several infectious diseases can cause rectal mass conditions in patients with HIV infection, including syphilis, LGV, CMV infection, and HHV-8 infection. [1,2,3] HHV-8 in the setting of HIV infection often becomes relevant in individuals with very low CD4 T-cell counts, in whom it manifests as Kaposi sarcoma. Human herpes virus 6 (HHV-6), another member of the herpes virus group, could also be r...