Cutaneous infection caused by Purpureocillium lilacinum: Case reports and literature review of infections by Purpureocillium and Paecilomyces in Taiwan

Abstract

Hyalohyphomycosis is a rare infection caused by a group of fungi that are devoid of pigments in their cell walls. As one of the main pathogens of hyalohyphomycosis, Purpureocillium lilacinum (former Paecilomyces lilacinus) is known for its intrinsic resistance to various antifungal agents. Here, we report three cases that coincide with a history of farming and all of them suffered from cutaneous hyalohyphomycosis caused by P. lilacinum. They shared a clinical presentation consisting of erythematous-to-violaceous painful plaques with overlying pustules on one of their forearms. Hyphae and fungal elements were highlighted by periodic acid Schiff or Gomori methenamine silver staining in their skin biopsies. Fungal cultures of their skin tissues yielded P. lilacinum, which was confirmed by both morphological and molecular characteristics. All patients responded well to oral terbinafine or itraconazole treatment. In this report, we also reviewed previously reported cases associated with either P. lilacinum or other Paecilomyces spp. infections in Taiwan.

Keywords: Purpureocillium lilacinum; Paecilomyces species; antifungal drug resistance; hyalohyphomycosis; mycoses.