Clinicodemographic Profile, Mycological Spectrum, and Associated Factors of Culture-Confirmed Onychomycosis in a Tertiary Care Hospital in Gqeberha, South Africa

Background: Onychomycosis is a common nail disorder caused by a wide range of pathogenic organisms and is often associated with underlying non-dermatological conditions and lifestyle-related factors. Emerging evidence suggests an increasing role of non-dermatophyte moulds (NDMs), previously regarded as contaminants. However, data describing the epidemiology and causative organisms of onychomycosis in South Africa remain limited. Methods: A retrospective cross-sectional study was conducted in the Department of Dermatology at Livingstone Hospital, Gqeberha, from 1 January 2019 to 31 December 2023. Clinical and laboratory records of 103 patients with culture-confirmed onychomycosis were reviewed and analyzed for demographic, clinical, and mycological characteristics. Results: The median age was 57 years, with a slight female predominance (54.4%). Toenail involvement (70.9%) was more frequent than fingernail involvement (43.7%). Almost all patients (95.1%) had at least one clinical risk factor or comorbidity. Nail discoloration (98.1%), particularly hyperpigmentation, was the most consistent clinical feature, followed by subungual hyperkeratosis (77.7%), onycholysis (59.2%), and nail dystrophy (52.4%). NDMs were the predominant pathogens (51.8%, n = 57/110), followed by yeasts (40.0%, n = 44/110) and dermatophytes (8.2%, n = 9/110). Alternaria, Penicillium, and Aspergillus were the most common NDMs, while Candida parapsilosis, Candida albicans, and Trichosporon species predominated among yeasts. Non-dermatophyte infections were significantly associated with subungual hyperkeratosis (p = 0.031), whereas yeast onychomycosis was associated with lower odds of subungual hyperkeratosis (p = 0.048). Conclusions: Nail discoloration was the most common clinical feature observed among patients with onychomycosis. The high prevalence of comorbidities suggests a possible association between onychomycosis and underlying health conditions. NDMs were the predominant fungal isolates in this study, highlighting the importance of accurate laboratory diagnosis for appropriate patient management.