In 2 patients with anhidrotic ectodermal dysplasia, we were able to show that the hypoplastic eccrine glandular elements may give rise to normal eccrine glands both anatomically and functionally, after repeated local application of acetylcholine. The perspectives of our findings for the therapeutic management of the anhidrotic ectodermal dysplasia are discussed and special attention is paid to the genetic background of the defect as well as the possible mode of action of acetylcholine.