INTRODUCTION
Nail disorders encompass a broad spectrum of infectious, inflammatory, neoplastic, and traumatic conditions that may present with overlapping clinical features. They represent approximately 10% of all dermatologic conditions, accounting for over 21.1 million ambulatory visits in the United States (US) between 2007 and 2016.1,2 While some entities, such as onychomycosis and onychocryptosis, are frequently encountered in clinical practice,1 others, such as nail unit melanoma and nail lichen planus, are rare and diagnostically challenging.3,4 Given their subtle presentations and visual similarity to benign mimics, nail diseases are a known source of diagnostic delay, with potential for significant patient morbidity when malignant or progressive pathology is missed.3 Even among dermatologists, diagnostic delays are common, driven by limited clinical exposure during training and insufficient confidence in performing nail-specific evaluations and procedures.5
Artificial intelligence (AI) has emerged as a promising adjunct in diagnostic medicine. AI-based tools have demonstrated strong performance in specialties such as radiology and ophthalmology, where pattern recognition is central to clinical reasoning.6 In dermatology, AI has been demonstrated to show a comparable accuracy to dermatologists in diagnosing skin cancer.7 Applications now extend to teledermatology triage, decision support, and patient education,8 with public-facing vision-language models (VLMs) like ChatGPT and Gemini broadening access across clinical and consumer settings.9
Despite these advances, most dermatologic AI studies have focused on pigmented skin lesions,7 with limited attention to the nail unit. Nail diseases are structurally and visually distinct from cutaneous lesions, requiring nuanced interpretation of morphology, color, and context. As such, diagnostic accuracy in this domain cannot be assumed based on performance in broader dermatologic tasks. Yet there remains a dearth of
Artificial intelligence (AI) has emerged as a promising adjunct in diagnostic medicine. AI-based tools have demonstrated strong performance in specialties such as radiology and ophthalmology, where pattern recognition is central to clinical reasoning.6 In dermatology, AI has been demonstrated to show a comparable accuracy to dermatologists in diagnosing skin cancer.7 Applications now extend to teledermatology triage, decision support, and patient education,8 with public-facing vision-language models (VLMs) like ChatGPT and Gemini broadening access across clinical and consumer settings.9
Despite these advances, most dermatologic AI studies have focused on pigmented skin lesions,7 with limited attention to the nail unit. Nail diseases are structurally and visually distinct from cutaneous lesions, requiring nuanced interpretation of morphology, color, and context. As such, diagnostic accuracy in this domain cannot be assumed based on performance in broader dermatologic tasks. Yet there remains a dearth of





