Photodynamic therapy treatment of superficial fungal infections: A systematic review.

Background: Fungal infections in skin, hair and nails affect up to 25 % of the global population. Conventional antifungal treatment is effective but due to resistance, treatment failure, drug interactions, and treatment related toxicity, there is a need for alternative treatments. Photodynamic therapy (PDT) has shown antimicrobial properties and is used increasingly for fungal infections. This review investigates the reported efficacy and side effects of PDT of superficial mycoses.

Methods: Pubmed and Embase were searched 26-01-2020 for "superficial fungal infections" and "photodynamic therapy" in "Human subjects" using a predefined search string. Criteria for inclusion were: clinical trials and cases involving PDT-treated patients with primary fungal infections in skin, hair and nails. Criteria for exclusion were: languages other than English, animal models, in vitro trials, secondary fungal infections, reviews and guidelines.

Results: 541 records were identified and 34 papers fulfilled the criteria. PDT of onychomycosis (n = 380 patients) found treatment with methylene blue (MB) photosensitizer (PS) more efficacious with complete cure rates of 70 %-80 % than 5-aminolevulinic acid (ALA)-PDT (mycological cure rates of 17 %-57 %) and methyl aminolevulinate (MAL)-PDT (mycological cure rate of 32 %). Other PDT-treated fungal diseases included (n = 55): foot infections (n = 19), tinea cruris (n = 10), scalp infections (n = 2), Malassezia infections (n = 9) and subcutaneous fungal infections (n = 15) achieved promising effect.

Conclusion: PDT-treatment of superficial mycoses can be efficacious as salvage therapy. In the light of increasing resistance and few licensed treatment alternatives, larger randomized controlled trials investigations and optimization of the PDT-treatment protocol are warranted to evaluate PDT's potential as a future antifungal treatment.