Keratosis, Nagashima-type is a transgressive and nonprogressive palmoplantar keratoderma resembling a mild form of mal de Meleda. The disease is Monarch Disease Ontology id MONDO_0014272 (palmoplantar keratoderma, Nagashima type). Also known as: PPK, Nagashima type, palmoplantar hyperkeratosis, Nagashima type.