Onychomycosis Caused byScopulariopsis brevicaulis: Report of Two Cases

Abstract

Onychomycosis is usually caused by dermatophytes, but some nondermatophytic molds and yeasts are also associated with invasion of nails. Scopulariopsis brevicaulis is a nondermatophytic mold found in soil as a saprophyte. We report two cases of onychomycosis caused by S. brevicaulis in a 48-year-old male and a 79-year-old female. The two patients presented with a typical distal and lateral subungual onychomycosis. Direct microscopic examination of the potassium hydroxide preparation revealed fungal elements. From toenail lesions of the patients, brown colonies with powdery surface, which are a characteristic of S. brevicaulis, were cultured on two Sabouraud's dextrose agar plates. Three cultures taken from nail plates within a 2-week interval yielded similar findings. Numerous branched conidiophores with chains of rough walled, lemon-shaped conidia were observed in slide culture by light microscopy and scanning electron microscopy. The nucleotide sequences of the internal transcribed spacer for the two clinical isolates were identical to that of S. brevicaulis strain WM 04.498. To date, a total of 13 cases of S. brevicaulis onychomycosis including the two present cases have been reported in Korea. Mean age of the patients was 46.1 years, with a higher prevalence in males (69.2%). Toenail involvement was observed in all cases including a case involving both fingernail and toenail. The most frequent clinical presentation was distal and lateral subungual onychomycosis in 12 cases, while one case was proximal subungual onychomycosis.

Nondermatophyte mould onychomycosis

“…19 Onychomycosis affects toenails more frequently than fingernails due to repeated trauma, slower growth, thicker nail plate, regular exposure to a moist environment in confined footwear, and reduced blood supply to underlying tissues. [20][21][22] Predisposing factors for NDM onychomycosis include 2,19,[23][24][25][26] : i hot and humid climate in tropical and subtropical areas 13 ii age, a common risk factor for onychomycosis due to lowered immune function, slower nail growth, long duration of exposure to pathogenic fungi, frequent nail trauma, and decreased perfusion of the lower extremity in the elderly 10,23,27,28 iii wearing occlusive footwear for an extended duration, a practice that incubates the organism in a warm, humid, confined environment which then predisposes toenails to onychomycosis. 19,29 (According to Zaias, this may be associated with signs of asymmetric gait nail unit syndrome [AGNUS] such as onycholysis, nail bed keratosis, and surface damage on the nail plate.…”

Ciclopirox and Efinaconazole Transungual Permeation, Antifungal Activity, and Proficiency To Induce Resistance in Trichophyton rubrum

“…Yeast infection due to Candida spp. (Candida albicans and/or Candida parapsilosis) accounts for 2% of onychomycosis, and 8% of toenail infections are due to nondermatophyte molds, particularly to Scopulariopsis brevicaulis (3–5). Onychomycosis is typically a chronic infection (disease duration is often >5 years) (6).…”

Association of Invasive Scopulariopsis brevicaulis Infection in a Case with Systemic Lupus Erythematosus

“…SLE patients have a predisposition to develop many infections which causes morbidity and mortality. Scopulariopsis brevicaulis is a nondermatophytic mold found in soil as a saprophyte [1]. Scopulariopsis infection mainly occurs in immunosuppressive individuals and may lead to invasive fungal infection.…”