The emerging role of photodynamic therapy in the treatment of cutaneous infections.

Introduction: Cutaneous infections pose ongoing challenges to standard treatments due to resistance and limited efficacy. Photodynamic therapy (PDT) emerges as a promising supplement or an alternative to address complicated cases. In this review, we comprehensively review PDT's safety and efficacy in treating cutaneous infections.

Evidence Acquisition: A PubMed systematic review with search terms for PDT treatment, hair, skin, and nail infections.

Evidence Synthesis: There were a total of 43 studies on the use of PDT in cutaneous infections which discussed the treatment of viral (N.=20), bacterial (N.=11), fungal (N.=9), and protozoal (N.=3) infections. There is evidence for using PDT, mostly 5-aminolevulinic acid (5-ALA) and methyl aminolevulinate (MAL), in the treatment of cutaneous infections. Most evidence for viral infections involved treatment with 5-ALA PDT in condyloma acuminatum (CoAc), verruca vulgaris, and molluscum contagiosum. In bacterial infections, 5-ALA and MB PDT have been used to achieve complete remission in refractory Pseudomonas and atypical mycobacteria infections without recurrence. In onychomycosis, MAL PDT achieved a 40.9% cure rate and MB PDT showed a 77.8-100% cure rate with no reports of recurrence. Parasitic infections, such as leishmaniasis have also been successfully treated with both 5-ALA and MAL PDT.

Conclusions: PDT is a promising treatment option for cutaneous infections, with growing evidence for its utility in treating cutaneous bacterial, viral, fungal, and parasitic infections, particularly those that fail standard treatments. Side effects were mostly limited to localized pain with good outcomes and low recurrence rates.