Photodynamic therapy in the treatment of onychomycosis: a comparative analysis of the efficacy of monotherapy and combined approach

Background: onychomycosis is a common infectious disease of the nail plates, characterized by a high rate of recurrence. Conventional treatment is limited by the side effects of systemic antifungal agents, particularly among patients with comorbidities. Photodynamic therapy (PDT) appears to be a promising alternative; however, data regarding its efficacy in various therapeutic regimens remain to be further studied and validated. Aim: to evaluate the efficacy of PDT as monotherapy and in combination with a shortened course of systemic antifungals in the treatment of toenail onychomycosis in patients with different degrees of disease severity. Materials and Methods: this prospective study included 48 patients with toenail onychomycosis (23 men and 25 women), who were randomized into two equal groups. The first group received PDT alone, with a chlorin e6-based photosensitizer (eight sessions). The second group received combination therapy: PDT in conjunction with a reduced course of systemic antifungal agents (terbinafine or itraconazole). All patients underwent mechanical preparation of the nail plates prior to treatment. Efficacy was assessed over a 9-month follow-up period, based on criteria for mycological and clinical cure. Results: by the ninth month, mycological cure was achieved in 91.7% of patients in the first group and in 100% of patients in the second group. Complete clinical cure was observed in 83.3% of patients in the first group and in 100% of patients in the second group (p<0.05). The combination therapy group showed less variability in the required number of procedures (8 8; 8 versus 8.5 8; 10.5, p<0.05). The SCIO index decreased in both groups, with a marked trend in the second group by the 9th month (p<0.05). Conclusion: PDT demonstrates high efficacy in the treatment of onychomycosis both as monotherapy and in combination with systemic antifungal agents. The combined approach offers more complete clinical cure and a standardized treatment protocol. This method may be recommended as an alternative or adjunctive strategy for the treatment of onychomycosis. KEYWORDS: onychomycosis, fungi, photodynamic therapy, photosensitizer, antifungals, systemic therapy, shortened course. FOR CITATION: Tsygankova E.I., Vasenova V.Yu. Photodynamic therapy in the treatment of onychomycosis: a comparative analysis of the efficacy of monotherapy and combined approach. Russian Medical Inquiry. 2025;9(6):306–311 (in Russ.). DOI: 10.32364/2587-6821-2025-9-6-2