Using HRA, the anal mucosa is visualized under magnification through a plastic anoscope after the application of acetic acid and Lugol's iodine. Abnormal-appearing areas are biopsied and if histologic AIN 2/3 is detected treatment is generally, but not always, offered. For anal dysplasia, treatment with surgery, infrared coagulation (IRC) electrocautery (EC) and topical therapies (e.g. trichloroacetic acid, or TCA) has been evaluated in case series. Similarly, given the high recurrence rate of CIN in women with HIV of about 65% after arguably more radical therapy, long-term, controlled trials of ablative therapies are still needed in HIV-infected MSM with high-grade AIN. There is some preliminary evidence that HPV immunization may reduce the likelihood of recurrent high-grade anal lesions in MSM after ablative therapy. These findings need further confirmation.