Objective To explore the application effect of carbon dioxide ablative fractional laser (CO₂-AFL) in photodynamic therapy (PDT) for condylomata acuminata (CA).

Methods A total of 80 patients with CA from January 2022 to December 2023 were randomly divided into two groups, with 40 cases in each group. Control group was treated with PDT mediated by 5-aminolevulinic acid (5-ALA) as a photosensitizer (5-ALA-PDT), while study group was treated with CO₂-AFL combined with 5-ALA-PDT. Both groups were treated for 4 weeks. Clinical efficacy, recurrence, and adverse reactions were compared between the two groups; additionally, serum inflammatory factors, immune function related indicators, local human papillomavirus (HPV) load, and the Dermatology Life Quality Index (DLQI) scores before treatment and 4 weeks after treatment were compared between the two groups.

Results The total effective rate was 97.50% in the study group, which was significantly higher than the 80.00% in the control group (P < 0.05). Four weeks after treatment, the levels of interleukin-2 (IL-2) and tumor necrosis factor-α (TNF-α) decreased significantly in both groups when compared with before treatment, while the levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), interleukin-10 (IL-10), and the ratio of T helper 1 to T helper 2 cells (Th1/Th2) increased significantly when compared with before treatment (P < 0.05); moreover, the levels of IL-2 and TNF-α in the study group were significantly lower than those in the control group, while the levels of IFN-γ, IL-4, IL-10, and Th1/Th2 in the study group were significantly higher than thosein the control group (P < 0.05). Four weeks after treatment, CD8⁺ level significantly decreased in both groups when compared with before treatment, while CD3⁺, CD4⁺, and CD4⁺/CD8⁺ levels increased significantly when compared with before treatment (P < 0.05); additionally, the levels of CD3⁺, CD4⁺ and CD4⁺/CD8⁺ in the study group were significantly higher than those in the control group, while CD8⁺ level was significantly lower in the study group (P < 0.05). Four weeks after treatment, the local HPV load and DLQI score significantly decreased in both groups when compared with those before treatment, and these indexes in the study group were significantly lower than those in the control group (P < 0.05). The incidence of adverse reactions was 10.00% in the study group, which showed no significant difference when compared to 5.00% in the control group (P>0.05). The recurrence rate within 6 months was 5.00% in the study group, which was significantly lower than the 22.50% in the control group (P < 0.05).

Conclusion Application of CO₂-AFL in 5-ALA-PDT for CA is effective, which helps to eliminate latent HPV viruses, improve serum levels of inflammatory factors, promote the recovery of immune function, and improve the quality of life of CA patients, with a low recurrence rate.