Kynsikandidoosi

Kynsikandidoosi, or nail candidiasis, is a fungal infection of the fingernails or toenails caused primarily by Candida species. It is a form of onychomycosis that is less common than dermatophyte infections and often occurs with moisture exposure or nail trauma. Candida species such as Candida albicans and non-albicans species (for example, C. parapsilosis, C. tropicalis) can infect the nail plate and surrounding tissue, sometimes with other fungi present.

Risk factors include repeated hand immersion in water, chronic paronychia, diabetes, immunosuppression, aging, and use of occlusive nail cosmetics or artificial nails. The condition more often affects the fingernails, but toenail involvement occurs as well.

Clinically, fingernail candidiasis may present with inflammation around the nail fold, while the nail itself can become thickened, yellow-brown, with subungual hyperkeratosis and possible onycholysis. Pain or secondary bacterial infection can occur, especially with paronychia.

Diagnosis relies on clinical assessment supported by laboratory tests. Microscopy with potassium hydroxide can reveal yeast and sometimes pseudohyphae; culture identifies the Candida species. Molecular methods (PCR) and histopathology may assist in uncertain cases and help distinguish Candida from dermatophytes or non-Candida moulds.

Treatment typically combines topical and systemic approaches. Topical antifungals (ciclopirox, efinaconazole, tavaborole) may be used for mild disease but are often insufficient alone for Candida infections. Systemic antifungals, such as fluconazole or itraconazole, are commonly used for nails affected by Candida, with treatment duration extending for several months and liver function monitoring advised. Debridement can improve drug penetration. Terbinafine is less effective against Candida.

Prognosis varies; relapse is possible. Prevention focuses on reducing moisture exposure, keeping nails short and dry, avoiding trauma, and managing diabetes or immune-related conditions.