The ectodermal dysplasias.

In order to be considered an ectodermal dysplasia, a disorder should meet the following criteria: it must be congenital; it must be diffuse (not localized) and must involve the epidermis as well as at least one of its appendages; and it must not be progressive. Included is a discussion of some well-documented, as well as some newer, conditions about which there appears to exist enough information to make some decisions concerning their categorization.