Efficacy and Safety of TCA vs. ECA for the Treatment of AIN in HIV-positive Patients

Inclusion Criteria: * HIV positive patients * Legally eligible patients and age ≥ 18 years * Sufficient knowledge of the German language, spoken and written * Patient is willing and able to appear regularly to the treatment- and follow-up appointments * Clinically visible AIN-lesion, which was confirmed by histopathology (findings not older than 2 weeks after the date of collection and removal date no longer than 16 weeks prior to baseline) * Written informed consent Exclusion Criteria: * Currently diagnosed anal cancer or anal cancer in anamnesis (within the last 5 years) * Acute life-threatening disease * Participation in a proctologic study within the last 30 days * Participation in this study at an earlier date * Simultaneous participation in another clinical trial, which excludes the participation in this study * Simultaneous topical and systemic treatments wtih medications that affect the study outcome, such as immunomodulatory substances: Interferone, imiquimod or systemic glucocorticosteroids * lactation * Pregnancy: In patients of childbearing age, a pregnancy has to be ruled out by pregnancy test or other suitable methods. * Women of childbearing potential without adequate contraceptive protection. * Contraindication for using trichloroacetic acid or electrocautery * Patients in whom general anesthesia in the treatment of AIN is necessary already at study start * Other serious intra-anal and proctologic disorders, which make additional proctologic or systemic tre…