Successful Treatment of Paecilomyces lilacinus Onychomycosis with Efinaconazole and Tavaborole

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.