Autosomal recessive hypohidrotic ectodermal dysplasia (AR-HED) is a rare genetic disorder that affects the development of the skin, hair, teeth, and sweat glands. People with AR-HED have sparse or absent scalp and body hair, dry skin, and missing or malformed teeth. They also have difficulty sweating, which can lead to overheating and other health problems. AR-HED is caused by mutations in the EDA, EDAR, or EDARADD genes. Treatment typically involves managing the symptoms and complications of the disorder.