Prevalence of onychomycosis in patients with autoimmune diseases.

BACKGROUND: Onychomycosis is the most common nail disorder in adults. Many studies reported a higher prevalence of onychomycosis among particular patients, such as those with diabetes, poor peripheral circulation or immunosuppression. However, studies of the prevalence of onychomycosis in autoimmune patients who carry many of these predisposing factors have been limited OBJECTIVE: Study the prevalence of onychomycosis in autoimmune compared to non-autoimmune female patients. MATERIAL AND METHOD: A cross-sectional study of the prevalence of onychomycosis in autoimmune patients and non-autoimmune female patients visiting a dermatology clinic over a period of 18 months. One hundred and sixty-five female autoimmune patients were enrolled. RESULTS: The prevalence of onychomycosis in autoimmune patients was 10.2% (95%CI 6.5%, 15.9%) compared to 6.7% (95%CI 3.8%, 11.6%), in non-autoimmune patients (p > 0.05, 2-sided). Of vesiculobullous patients, mainly presenting with pemphigus and who were mostly on immunosuppressive medication, 24% had onychomycosis [p = 0.013; OR 4.39 (95%CI 1.27, 14.89)]. CONCLUSION: Exposure to humid microenvironments was an important factor in the occurrence of onychomycosis (p < 0.05, 2-sided). However, the number of patients with each individual disease was too small to conclude a prevalence of onychomycosis in conjunction with these individual cutaneous autoimmune diseases.

Clinical characteristics and mycology of onychomycosis in autoimmune patients.

Onychomycosis is the most common nail disorder in adults. Predisposing factors are immunosuppression, poor peripheral circulation, diabetes mellitus, increasing age, nail trauma, and tinea pedis. Autoimmune patients, who carry many of these predisposing factors, have never been studied. Autoimmune patients, with underlying autoimmune skin diseases; pemphigus, systemic lupus erythematosus (SLE), mixed connective tissue disease (MCTD), scleroderma, dermatomyositis and cutaneous vasculitis, as well as having abnormal-appearing nail(s) with suspicion of fungal nail infection were included. Clinical information was obtained. The causative organisms were identified by potassium hydroxide preparation and cultured. Duration of onychomycosis in autoimmune patients was twice longer than in non-autoimmune patients. Of those with mycological proven onychomycosis, the autoimmune patients had significantly more affected nails (p < 0.05; chi2, two-sided) compared to the non-autoimmune patients but there was no difference in the affected fingernails or toenails and clinical type of onychomycosis. Candida spp was the most frequently found in autoimmune subjects compared to dermatophytes, Trichophyton rubrum. However, dermatophytes especially Trichophyton rubrum was the most common causative organism in non-autoimmune samples, followed by Candida spp. The causative organisms were more frequently discovered in autoimmune patients, whether by potassium hydroxide (KOH) or culture, than in non-autoimmune patients (p < 0.05; chi2, two-sided).