Feline sporotrichosis successfully treated with methylene blue-mediated antimicrobial photodynamic therapy and low doses of itraconazole

Abstract

Sporotrichosis is a mycotic infection of humans and animals caused by different fungal species of the genus Sporothrix. Feline sporotrichosis presents a broad spectrum of clinical manifestations and its treatment with classic antifungal drugs is often long and frustrating. Methylene blue-mediated antimicrobial photodynamic therapy (MB-APDT) comes to light as an interesting approach against fungal infections, including sporotrichosis. In this case report, a 1-year-old male cat was diagnosed with sporotrichosis, being confirmed by fungal culture. The cat was treated by MB-APDT combined with oral administration of itraconazole. Following 2 weeks after the end of treatment, the animal was clinically cured, and an additional fungal culture was negative for Sporothrix spp., confirming the total remission of sporotrichosis. No side effects and recurrences were observed after a 3-moth follow-up. MB-APDT is a promising strategy against feline sporotrichosis, however large-scale studies are welcome to confirm its potential.