Cryotherapy for anogenital warts: factors affecting therapeutic response

Human papilloma virus genital infection remains a treatment dilemma; there is still no gold standard therapy, treatment options are limited, expensive and often ineffective, and recurrence rates are relatively high. The primary objective of this study is to establish the efficacy, safety, and tolerability of cryotherapy in the treatment of these lesions. From 1999 to 2003, 100 consecutive patients with at least ten genital warts were treated with liquid nitrogen cryotherapy using a cotton-tipped applicator and two freeze-thaw cycles at the outpatient dermatology clinic of Hazrat-e Rasool University Hospital. Treatment was repeated every 3 weeks until the disappearance of all visible lesions was achieved. Patients were followed up every 4 months for 18 months. Complete clinical cure (CCC) was defined as complete clearance of all lesions and no evidence of disease for a minimum of 18 months. The CCC and relapse rate were evaluated based on different demographic and clinical characteristics. Overall, 86 percent of the patients achieved CCC after an average of 3.31 treatment sessions. All of the failed cases were attributed to recurrence of warts in new sites. The cure rate increased in parallel with increasing treatment sessions until the 6th session, after which it remained constant. The cure rate was lower and the number of treatment sessions higher in older patients. The age of the patient and number of treatment sessions affect the cure rate. The recurrence rate was significantly higher for the married or multi-partner group than for unmarried patients. We concluded that cryotherapy is an effective method for treatment of anogenital warts. The age of the patient and size of the lesions affect the cure rate. However, the most important factor in relapse of the lesions is unprotected sexual contact during and after treatment.