Photodynamic therapy efficiently controls dermatophytosis caused byTrichophyton rubrumin a murine model

Funding sources: Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG). Conflicts of interest: none declared. Dear Editor, Dermatophytes are filamentous fungi that use keratin to colonize the host, causing superficial infections called dermatophytoses. Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum spp. and Epidermophyton spp. are important aetiological agents worldwide.1 A few drugs, including azoles (itraconazole), allylamines (terbinafine) and hydroxypiridones [ciclopirox olamine (CPX)], are available for the treatment of dermatophytoses,1 2 but the widespread use of antifungals has been linked to the emergence of resistant strains of T. rubrum.2 This problem may jeopardize treatment and thereby justifies the search for new therapeutic strategies. Antimicrobial photodynamic therapy (aPDT) combines a photosensitizer and a nonthermal light source to induce a reaction that results in cell death.3 In the presence of molecular oxygen, aPDT triggers the production of reactive oxygen (ROS) and reactive nitrogen species,4 which have short lifetimes and limited diffusion through the tissue, explaining the localized damage induced by aPDT.3 4 Previously, we have shown that T. rubrum is susceptible to photodynamic inhibition using toluidine blue (TBO) and light‐emitting diode (LED) at 630 nm;4 however, there is a lack of studies regarding its efficacy in vivo.5 Therefore, the aim of this study was to evaluate the effects of aPDT, using TBO and LED, in controlling T. rubrum infection in a murine model of dermatophytosis.