onychom

Onychom is an informal abbreviation commonly used in clinical and research contexts to refer to onychomycosis, a fungal infection of the nail unit. The term derives from the Greek “onyx” meaning nail and the suffix “‑mycosis” indicating a fungal disease. Onychom primarily affects the toenails, but fingernail involvement also occurs, especially in individuals with compromised peripheral circulation, diabetes, or immunosuppression.

Etiology

The infection is most frequently caused by dermatophyte species such as Trichophyton rubrum and Trichophyton interdigitale, although non‑dermatophytic molds and yeasts (e.g., Candida spp.) can be implicated. These organisms invade the nail plate, bed, and surrounding tissue, leading to progressive discoloration, thickening, and brittleness.

Epidemiology

Onychom is one of the most common nail disorders worldwide, with prevalence estimates ranging from 2 % to 13 % in the general population and higher rates in older adults. Women are slightly more affected than men, possibly due to footwear choices and cosmetic practices.

Clinical presentation

Typical signs include yellow to white discoloration, onycholysis (separation of the nail from the nail bed), subungual hyperkeratosis, and a crumbly texture. Diagnosis relies on clinical examination supplemented by microbiological testing—direct microscopy, culture, or molecular methods—to identify the causative organism.

Management

Treatment options comprise topical antifungal agents (e.g., ciclopirox, amorolfine), oral systemic therapy (e.g., terbinafine, itraconazole), and mechanical debridement. Choice of therapy depends on the severity, pathogen, patient comorbidities, and risk of drug interactions. Preventive measures emphasize proper foot hygiene, keeping nails trimmed, and avoiding moist environments that favor fungal growth.