Diagnostic pitfalls in anhidrotic ectodermal dysplasia: Indications for palmar skin biopsy

A 4-week-old Puerto Rican boy who had had severe, episodic pyrexia since birth was evaluated for anhidrotic ectodermal dysplasia (AED). Direct examination of the palms and volar aspects of the fingertips gave equivocal results. A punch biopsy of the hypothenar eminence showed the absence of intradermal eccrine glands and ducts but the presence of poorly formed intraepidermal eccrine ducts. There are a number of pitfalls in the use of noninvasive technics for diagnosis of anhidrotic ectodermal dysplasia, whereas the palmar skin biopsy, although invasive, is performed at virtually no risk, and almost always gives unequivocal results.