Scytalidium dimidiatum melanonychia and scaly plantar skin in four patients from the Maghreb: imported disease or outbreak in a Belgian mosque?

Scytalidium dimidiatum is a geophilic dematiaceous, non-dermatophyte mould that can become a pathogen for plants and humans particularly in tropical and subtropical regions. We report 4 cases of S. dimidiatum onychomycosis presenting clinically as thickened and dark toenails. The skin of the soles was scaly. The time and location of the contaminations were uncertain. Indeed, the patients were ancient immigrants from the Maghreb to Belgium. They were also regularly travelling to their countries of origin. They were also often barefoot in the same Belgian mosque. The disease was unresponsive to current oral antifungal treatments.