DOI: https://doi.org/10.36347/sjmcr.2025.v13i11.020

Pages: 2744-2747

Background: Non-dermatophyte mold (NDM) infections of the nail apparatus are being reported with increasing frequency, though they remain diagnostically challenging. Alternaria species, a dematiaceous saprophytic mold, is a particularly uncommon cause of onychomycosis. Because NDMs are often dismissed as contaminants, genuine infections may be under-recognized. Case presentation: We describe a chronic case of dystrophic right great-toenail infection caused by Alternaria species in an immunocompetent adult with no antecedent trauma, systemic illness, or prior antifungal therapy. Diagnosis was confirmed through direct microscopy and fungal culture, which identified Alternaria species. Discussion: This report highlights the complex pathogenesis, diagnostic pitfalls, and therapeutic challenges of Alternaria onychomycosis. The case illustrates that non-dermatophyte organisms may infect healthy hosts, underscore the importance of laboratory confirmation, and discuss current evidence regarding antifungal management. Conclusion: Accurate identification of NDM infections, including those due to Alternaria, is essential for optimal therapy and prevention of recurrence. Clinicians should suspect these organisms in cases of long-standing nail dystrophy unresponsive to conventional treatment.