To investigate the effect and safety of CO₂ fractionnal laser and liquid nitrogen cryotherapy pretreatment combined with 5-aminolaevulinic acid-based photodynamic therapy (ALA-PDT) on the photodynamic therapy treatment of perianal condyloma acuminatum.

Total of 164 patients with perianal condyloma acuminatum were collected from January 2016 to June 2022 in the Department of Dermatology, Beijing Anzhen Hospital, Capital Medical University, aged 17-75 [31 (25, 36)] years old, disease course was 3-56 [12 (6, 24)] weeks. The patients were divided into 3 groups randomly, the control group was treated with ALA-PDT, the CO₂ laser pretreatment group (CO₂ group) was given CO₂ fractional laser pretreatment combined with ALA-PDT treatment, and the liquid nitrogen cryotherapy pretreatment treatment group (cryotherapy group) was given liquid nitrogen cryotherapy pretreatment combined with ALA-PDT treatment. The treatment effect was calculated according to the number of lesions and the degree of improvement of the patient, and the treatment effect was compared and analyzed by Chi-square test and U-test of rate.

During the follow-up of 3 months after treatment, the recurrence rate of control group (9.6%) was significantly higher than those of CO₂ group (1.8%) and cryotherapy group (1.8%), and without significant difference (U = 1.7749, P = 0.0759; U = 1.7749, P = 0.0759). There was no significant difference in recurrence rates between CO₂ group and cryotherapy group (U = 0.0000, P = 1.0000). During the follow-up of 6 months after treatment, 4 patients (8.51%) in control group relapsed, and there was no recurrence in both CO₂ group and cryotherapy group. The overall clearance rate of treatment was significantly lower in control group (91.49%) than those in CO₂ group (100%) and cryotherapy group (100%) (U = 0.0759, P = 0.0273; U = 0.0759, P = 0.0273). The incidences of pain after treatment in CO₂ group, cryotherapy group and control group were 7 (12.5%), 6 (10.7%) and 6 (11.5%), respectively, without significant difference (χ² = 0.6122, P = 0.0470). The incidences of infection after treatment in CO₂ group, cryotherapy group and control group were 1 (1.8%), 0 (0.0%) and 1 (1.9%), respectively, without significant difference (Fisher’s exact probability test: P = 0.7654).

For patients with perianal condyloma acuminatum, CO₂ laser and liquid nitrogen cryotherapy pretreatment combined with ALA-PDT were better than ALA-PDT alone, and did not increase the incidence of adverse reactions.