Clouston syndrome (or hidrotic ectodermal dysplasia) is characterized by the clinical triad of nail dystrophy, alopecia, and palmoplantar hyperkeratosis. The disease is Monarch Disease Ontology term MONDO_0007510 (Clouston syndrome). Also known as: Clouston's hidrotic ectodermal dysplasia, Clouston's syndrome, hidrotic ectodermal dysplasia, hidrotic ectodermal dysplasia syndrome.