Fusarium onychomycosis: prevalence, clinical presentations, response to itraconazole and terbinafine pulse therapy, and 1-year follow-up in nine cases.

BACKGROUND: Invasive fusariosis is an infection with Fusarium spp. that primarily affects patients with hematologic malignancies and hematopoietic cell transplant recipients. Wounds, digital ulcers, onychomycosis, and paronychia are the typical cutaneous portals of entry. Early management of mycotic nails in immunocompromised and diabetic hosts is crucial to prevent life-threatening disease. OBJECTIVES: We report nine cases of Fusarium onychomycosis (F. dimerum, n = 5; F. oxysporum, n = 3; Fusarium spp., n = 1) in immunocompetent hosts and their response to itraconazole and terbinafine pulse therapy. METHODS: The patients received either itraconazole 400 mg daily or terbinafine 500 mg daily for 7 d/month; two pulses for fingernails and three pulses for toenails. RESULTS: Of the 68 confirmed cases of onychomycosis, eight (11.7%) were Fusarium spp.; the ninth patient was culture positive but microscopy negative and responded well to itraconazole. Distal subungual onychomycosis was the commonest clinical manifestation (seven of nine), one had proximal subungual onychomycosis, and total onychodystrophy was noted on four patients. Associated paronychia was marked on 66.7% (six of eight) patients. Itraconazole was given to six patients/25 nails and terbinafine to three patients/20 nails. All nine patients completed treatments, but one defaulted at 12 months follow-up. The efficacy parameters were clinical cure (CC) and mycological cure (MC). At month 12 after the start of treatment, the response was itraconazole CC 13 of 25 (52%)/MC four of six (66.6%) and terbinafine CC four of eight (50%)/MC one of two (50%). Recurrence was noted in four of 13 (30.7%) and eight of 13 (61.5%) cured nails in the itraconazole group within 3 and 12 months, respectively. CONCLUSIONS: Fusarium onychomycosis was clinically indistinguishable from other onychomycosis. Both itraconazole and terbinafine pulse therapy were only partially effective on Fusarium onychomycosis. Antifungals that are more effective should be sought.