Nannizzia incurvata as a rare cause of favus and tinea corporis in Cambodia and Vietnam

Abstract

Nannizzia (N.) incurvata (formerly Microsporum incurvatum) represents a geophilic dermatophyte which has been previously classified as belonging to the species complex of N. gypsea (formerly Microsporum gypseum). A 42-year-old Vietnamese female from Saxony, Germany, suffered from tinea corporis of the right buttock after she returned from a 2-week-visit to her homeland Vietnam. From skin scrapings of lesions, N. incurvata grew on Sabouraud’s dextrose agar. Treatment by ciclopirox olamine cream twice daily for 4 weeks was successful. A 6-year-old Cambodian boy living near river Mekong with contact history to chicken, dogs and cattle suffered from tinea faciei and capitis. Symptoms of the favus-like tinea capitis and tinea faciei were erythema and scaly patches with areas of alopecia. N. incurvata grew on Sabouraud's dextrose agar. The boy was treated with oral terbinafine 125 mg daily, topical miconazole cream and ketoconazole shampoo. The symptoms healed within 4 weeks of treatment. Cultivation of the samples revealed growth of N. incurvata. For confirmation of species identification, the isolates were subject to sequencing of ITS (internal transcribed spacer) region of the rDNA, and addition of the “translation elongation factor 1 α” (TEF 1 α) gene. Sequencing of the ITS region showed 100% accordance with the sequence of N. incurvata deposited at the NCBI database under the accession number MF415405. N. incurvata is a rare, or might be underdiagnosed geophilic dermatophyte described in Sri Lanka and Vietnam until now. This is the first isolation of N. incurvata in Cambodia, and the first description of favus in a child due to this dermatophyte.