pachyonychia
Pachyonychia refers to thickening of the nails (onychauxis), a descriptive finding that may occur as an isolated nail dystrophy or as part of a genetic syndrome known as pachyonychia congenita (PC). PC is a rare autosomal dominant disorder in which nail dystrophy is accompanied by painful keratoderma of the palms and soles and mucocutaneous keratoses, typically presenting in infancy or early childhood. The hallmark features are chronically thickened, dystrophic nail plates with subungual hyperkeratosis, along with palmar-plantar keratoderma. Oral keratoses, follicular hyperkeratosis, and hair abnormalities can occur in some cases.
Genetically, PC is caused by mutations in keratin genes, most commonly KRT6A, KRT16, and KRT17. PC is
Diagnosis is based on clinical findings and family history; genetic testing confirms the diagnosis and identifies
Management is supportive and multidisciplinary. There is no cure; treatments aim to reduce hyperkeratosis and pain