Successful Treatment of Paecilomyces lilacinus Onychomycosis with Efinaconazole and Tavaborole

Abstract

Paecilomyces lilacinus, also known as Purpureocillium lilacinum, is a non-dermatophyte mold found in the soil and used as nematocide for crops. P. lilacinus can cause rare opportunistic infections in humans ranging from endocarditis, keratitis, to onychomycosis with significant resistance to conventional antifungals. There are only two cases of onychomycosis caused by P. lilacinus reported in the literature and none that were successfully treated. Here we present a case of successfully treated onychomycosis caused by P. lilacinus with efinaconazole and tavaborole in a patient who had failed treatment with oral fluconazole, itraconazole, terbinafine, and topical ciclopirox and naftifine.

Keywords: Efinaconazole; Non-dermatophyte; Onychomycosis; Paecilomyces lilacinus; Purpureocillium lilacinum; Tavaborole; Treatment.

Fig. 1

Right great toenail P. lilacinus onychomycosis showing distal onycholysis, subungual debris, and yellow discoloration prior to treatment with topical efinaconazole and tavaborole.

Fig. 2

Right great toenail showing attached distal nail plate without subungual debris or thickened nail bed, status post 4 months treatment with efinaconazole and 2 weeks of tavaborole topical application for P. lilacinus onychomycosis. An incidental non-fungal-related torn nail due to traumatic injury is shown.