# Prevalence of onychomycosis among psoriasis patients: a clinico-mycological and dermoscopic comparative cross sectional study

## TL;DR

This study finds that 22% of psoriasis patients with nail issues also have onychomycosis, a fungal nail infection, and identifies key signs to help distinguish the two conditions.

## Contribution

The study provides a comparative analysis of dermoscopic features and mycological findings to improve diagnosis of onychomycosis in psoriasis patients.

## Key findings

- 22% of psoriasis patients with nail disease tested positive for onychomycosis.
- Dermatophytes, yeast, and non-dermatophytic molds were isolated in 2%, 14%, and 38% of onychomycosis cases, respectively.
- Spikes were the most common dermoscopic sign in onychomycosis, while nail pitting was most common in nail psoriasis.

## Abstract

Onychomycosis, a nail infection caused by dermatophytes, yeast, and molds makes up roughly half of all onychopathies and is the most prevalent nail condition in the world. Clinically, nail psoriasis and onychomycosis can frequently be difficult to distinguish from one another. To assess the prevalence of onychomycosis in patients with psoriasis. Fifty patients with psoriasis associated with nail disease were included in this study. After taking clinical history, nail samples were gathered for dermoscopic inspection, culture, direct microscopy with 20% KOH solution, and nail clipping with PAS stain. Of the 50 patients recruited, 43 were males and 7 were females, with mean age 6–71 years (mean ± SD 44.06 ± 16.2). Eleven patients (22%) tested positive for onychomycosis. Dermatophytes were isolated from 2% of patients, yeast from 14% of patients, and non-dermatophytic mold from 38% of patients. Histopathological results revealed fungal hyphae and spores in 18% of patients. The most prevalent dermoscopic sign in psoriatic patients with onychomycosis was spikes (81.8%) with statistical significance (P-value < 0.001), while nail pitting was the most prevalent dermoscopic feature in nail psoriasis. This study lays the way for an accurate diagnosis of nail lesions by highlighting the significance of cooperation between mycology, histology, and dermoscopy in the diagnosis of onychomycosis in patients with nail psoriasis.