Ectodermal dysplasia

Alternative names:

anhidrotic ectodermal dysplasia

Definition:

A hereditary condition characterized by abnormal development of the skin and associated structures (hair, nails and teeth, and sweat glands).

Causes, incidence, and risk factors:

There are several different types of ectodermal dysplasia of which X-linked anhidrotic ectodermal dysplasia is the most common. This condition affects only males. An autosomal dominant form exists in which females and males are equally affected and is symptomatically almost identical to the X-linked form of the disease.

Ectodermal dysplasia may affect, to varying degrees, all of the structures associated with the development of the skin. Absent or decreased sweating in people with anhidrotic ectodermal dysplasia is caused by absence of sweat glands. Affected children have difficulty controlling fevers and mild illness may produce extremely high fevers, because of absent temperature regulation by sweating. Affected adults are unable to tolerate a warm environment and require special measures to maintain a normal body temperature.

Mucus membrane involvement results in chronic nasal infections with foul-smelling discharge and increased respiratory infections. Hair may be absent or very scanty. The skin is thin with light pigmentation. Teeth develop abnormally and many teeth are missing.