Photodynamic Therapy for the Management of Onychomycosis: A Promising Strategy

Onychomycosis is a fungal infection of the toenails and fingernails that results in thickening, discoloration, splitting as well as lifting of the nails from the nail bed. It affects 14% of the total world population, with more prevalence in elders and diabetics. Both dermatophytes (Trichophyton rubrum or Trichophyton mentagrophytes) and nondermatophytes (Scopulariopsis brevicaulis, Aspergillus spp, Fusarium spp, and sometimes Candida spp) have been identified as etiologic agents of onychomycosis. The treatment of onychomycosis is known to be challenging since it is chronic, difficult to eradicate and tends to relapse. Multiple therapies, including surgical, chemical, topical, and oral methods, have been described for its treatment. However, several factors like the difficulty of achieving penetration of the nail plate, lack of adherence to treatment (which lasts for months), the poor response of some fungi to antifungals, and individual susceptibility lead to poor treatment outcomes [1]. The complete cure comprised of clinical cure (implying nail clearing) and mycological cure (both negative microscopy and dermatophyte culture) is often unattainable [2]. Therefore, there is a need to expand treatment options and reduce the adverse effects associated with the conventional therapies. The photodynamic therapy (PDT) is a one of the interesting option that can help to overcome the limitations described above.