Endonyx toenail onychomycosis caused by Trichophyton rubrum: treatment with photodynamic therapy based on methylene blue dye

Abstract

This study shows the effectiveness of photodynamic therapy based on methylene blue dye for the treatment of endonyx toenail onychomycosis. Four patients with endonyx onychomycosis caused by Trichophyton rubrum were treated with 2% methylene blue aqueous solution irradiated with light emission diode at 630 nm and an energy density of 36 J/cm2 for 6 months at 2-week intervals. The preliminary study showed the effectiveness of this therapy in the treatment of endonyx onychomycosis, and also indicated that the disease can be caused by T. rubrum.

Global perspectives for the management of onychomycosis

“…The majority of clinical trials published on devices originate from South American (e.g., Brazil) and East Asian countries (e.g., Japan, Korea, China) . Device‐based treatments in combination with other therapies may help improve the penetration of antifungal drugs and treatment efficacy .…”

Efficiency of methylene blue‐mediated photodynamic therapy vs intense pulsed light in the treatment of onychomycosis in the toenails

“…The characteristic colour of MB is caused by the strong absorption band in the 550‐700 nm region with maximum molar absorptivity of 85 000 M ‐1 cm ‐1 at 664 nm . In the present study a 2% solution of MB in water was employed, following the successful pattern described by Souza et al in their three published woks . Unlike these studies, in the Group 1 of the present work, MB was photoactivated with laser radiation at 670 nm (very near to its peak of maximum absorption −668 nm‐), instead of the LED lamp at 630 nm used by them.…”

“…This negative image associated with onychomycosis justifies current efforts to develop new treatment modalities like those based on PDT principles. PDT has been shown to be effective in photoinactivation of multiple species of fungi including the most common cause of onychomycosis T. rubrum . Development of antimicrobial resistance after PDT treatment appears to be unlikely since, in microbial cells, singlet oxygen and other free radicals—all of them originated from this type of therapy—affect a range of cellular targets, something that does not happen in conventional antimicrobial therapy …”

Photodynamic therapy in the treatment of onychomycosis – a review

“…Also, the authors of one study point out that the clinical response to PDT was superior in the treatment of mild and moderate mycosis (100%) to severe toenail onychomycosis (63.3%). Importantly, the highest cure rate has been observed in patients with the distal-lateral type of onychomycosis and endonyx onychomycosis which is a relatively rare presentation of the disease [26][27][28].…”

“…Ponadto opublikowano badanie, w którym uzyskano lepszą odpowiedź kliniczną w przypadku zastosowania PDT w leczeniu grzybicy o łagodnym i umiarkowanym nasileniu (100%) niż grzybicy paznokci stóp o znacznym nasileniu (63,3%). Największy odsetek wyleczeń obserwowano u pacjentów z odmianą dystalno-boczną oraz wewnątrzpłytkową, która jest dość rzadka [26][27][28].…”