This 5-year-old boy developed a progressive nail dystrophy shortly after birth. During the first year he also developed horny follicular papules on the extensor surfaces of his arms and legs and white plaques on the tongue, palate, and buccal mucosa. He had no eye involvement or palmar-plantar keratoderma, and his growth and development were normal. His only complaint was pain associated with intense physical activity resulting in trauma to his toes and toe nails. His mother was able to keep his finger nails well filed but could not reduce toe nail symptoms. This child exemplifies the most common variant of pachonychia congenita which is inherited as an autosomal dominant disorder and associated with mutations in the gene coding either for keratin 6 or 16.
