Ectodermal Dysplasia (ED) is a group of rare disorder that affects various tissues of ectodermal origin. The most common form is hypohidrotic (anhydrotic) ED of X-linked recessive type affecting only males.

Two daughters one four years and another one year of age from a consanguineous married muslim family were admitted in the pediatric department of Burdwan Medical College, West Bengal with history of high grade fever and cough of short duration with a background history of frequent rise of body temperature since early infancy. Absence of sweating even in hot summer, lack of hair and abnormal dentition were associated complaints. Family history revealed healthy parents with these two daughters without history of similar illness in relatives. Clinical examination showed IAP grade III PEM without edema, occasional thin strands of silky hair giving the appearance of total baldness, absent eyelash, frontal bossing, depressed nasal bridge and dry skin but normal nails in both of them. Elder sister had only two conical upper incisor teeth but the younger had none. Others systemic examinations revealed no abnormality except few crackles in lungs. Palmer skin biopsy of both the sisters showed thinned out epidermis, absence of sweat glands and pilosebacious unit in dermis suggestive of hypohidrotic (anhidrotic) ED. Other investigations were inconclusive. ARI responded to oral cotrimoxazole.

The ED is a heterogeneous group of disorders by constellation of findings involving defects of two or more of the following the teeth, skin and appendageal structures including hair, nails and eccrine and sebaceous gland(1). This disorder was first described by Thurunam in 1848(2). The incidence has been reported to be 1 per 10,000 to 1 per 100,000 live births(3). Clinically, ED are of two types: hypohydrotic (anhydrotic) and hydrotic. Hypohidrotic ED is manifested as a triad of defects: partial or complete absence of sweat glands, anomalous dentition and hypotrichosis, anodontia or hypodontia with widely spaced, conical teeth is a constant feature(1). Episodes of high fever in warm environment, dry skin, sparse hypopigmented hair, frontal bossing, flattened nasal bridge are some of other features, Poor development of mucous glands in the respiratory tract may result in increased susceptibility to respiratory infection.

In our presenting case both the sisters satisfied most of the clinical features of hypohidrotic (anhidrotic) ED which was confirmed by palmar skin biopsy.

The mode of inheritance of ED is X-linked recessive with full expression only in males; however, an autosomal recessive mode of inheritance may be operative in some families(1). Monoz, et al. in 1997(4) suggested that heterozygous females of unaffected mother having variable clinical features of ED occur because of random X- inactivation (Lyon hypothesis) and mosaic of functionally normal and abnormal cells. The inheritance of presenting case may be autosomal recessive or random X-inactivation. However, genetic analysis was not possible in our working set up.

1. Gray LD. Ectodermal Dysplasia. In: Nelson Textbook of Pediatrics. Behrman RE, Kliegman RM, Jenson HB, editors. 16th edn. W.B. Saunders Company 2000; p. 1974-1975.

2. Priolo M, Lagan C. Ectodermal dysplasia: A new clinical-genetic classification. Med Genet 2001; 38: 579-585.

3. Sepulveda W, Sandoval R, Carstens E, Gutierrez J, Vesquez P. Hypohidrotic ectodermal dysplasia: prenatal diagnosis by three dimensional ultrasonography. 2003; 22: 731-735.

4. Munoz F, Lestringant G, Sybert V, Frydman M, Alswaini A, Frossard PM, et al. Definitive evidence for an autosomal recessive form of hypohidrotic ectodermal dysplasia clinically indistinguishable from the more common X-linked disorder. Am J Hum Genet 1997; 61: 94-100.