Journal of Indian Society of Pedodontics and Preventive Dentistry
Journal of Indian Society of Pedodontics and Preventive Dentistry
                                                   Official journal of the Indian Society of Pedodontics and Preventive Dentistry                           
Year : 2010  |  Volume : 28  |  Issue : 1  |  Page : 47--54

Hypohidrotic ectodermal dysplasia - Diagnostic aids and a report of 5 cases

K Ramesh1, D Vinola2, John B John3,  
1 Professor, Department of Pedodontics and Preventive Dentistry, VMSDC, Salem, Tamilnadu, India
2 Senior Lecturer, Department of Pedodontics and Preventive Dentistry, VMSDC, Salem, Tamilnadu, India
3 Former Professor and HOD, Department of Pedodontics and Preventive Dentistry, VMSDC, Salem, Tamilnadu, India

Correspondence Address:
K Ramesh
Department of Pedodontics and Preventive Dentistry, VMS Dental College, NH47, Sankari Main Road, Ariyanoor, Salem - 636 308


Hypohidrotic ectodermal dysplasia (HED) is a rare group of disorders affecting the hair, teeth, nails and sweat glands to a variable degree. There is a wide range of clinical presentation of HED. Missing teeth or abnormal tooth form may be the first indicator of the disorder. We present a case report of 5 cases of HED with their intraoral findings and their treatment plan. We also consider the various etiological factors and their clinical diagnostic aids.

How to cite this article:
Ramesh K, Vinola D, John JB. Hypohidrotic ectodermal dysplasia - Diagnostic aids and a report of 5 cases.J Indian Soc Pedod Prev Dent 2010;28:47-54

How to cite this URL:
Ramesh K, Vinola D, John JB. Hypohidrotic ectodermal dysplasia - Diagnostic aids and a report of 5 cases. J Indian Soc Pedod Prev Dent [serial online] 2010 [cited 2021 May 8 ];28:47-54
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Full Text


Ectodermal dysplasias (EDs) are a large group of syndromes that are heterogenous under clinical and genetic aspects, and are characterized by anomalies in the structures of ectodermal origin. They can be manifested in problems relating to hair, nails, teeth, sweat and sebaceous glands, epithelium, conjunctiva, nervous system etc. Incidence of EDs is estimated to be 7 in 10,000 live births. [1]

More than 192 distinct disorders have been described.The most common EDs are X-linked recessive hypohidrotic and hidrotic. [2] The disorder is determined by the X-linked recessive gene, so the disease is more observed in males than females. [3]

 Case Report

A total of 5 cases of patients who reported to the Department of Pedodontics with features of scanty hair, scaly skin, frontal bossing, anodontia/oligodontia were diagnosed as hypohidrotic ectodermal dysplasia [Table 1].



Thurman (1848) first reported 2 male first cousins and their maternal grandmother with a hereditary syndrome associated with sparse hair, missing teeth and dry skin. HED was the condition affecting the "toothless men of Sind," members of a Hindu family residing in the vicinity of Hyderabad, as described by Darwin (1875) and Thadani (1934).

Graves (1963) reported a highly literate account of the large southern Mississippi group affected with this disorder. This was also described in the Work Projects Administration WPA guide, 1938, wherein these individuals were referred to as "Whitaker Negroes." [4]


Ectodermal dysplasia results from the abnormal morphogenesis of cutaneous or oral embryonal ectoderm, with reduction in the number of hair follicles and with hair shaft abnormalities.

Eccrine defects: Eccrine sweat glands may be absent or sparse and rudimentary.

Dental defects: Abnormal morphogenesis or absence of teeth.

Nail dystrophy: Abnormal nail plate with brittle, thin ridged or grossly deformed nails. [2]


X-linked recessive hypohidrotic ED (Christ-Siemens-Touraine syndrome), or anhidrotic ectodermal dysplasia and immunodeficiency (EDA-ID), is caused by mutations in gene EDAEDA, which encodes the ectodysplasin protein, which in turn activates the NF-kappaB and essential modulator (NEMO), resulting in conical teeth, sparse hair, anhidrosis or hypohidrosis, and recurrent bacterial infections. [5]Autosomal dominant hypohidrotic ED is caused by mutations in the DL gene, which encodes the EDA (ectodysplasin) receptor. [6]Autosomal recessive hypohidrotic ED may also result from mutations in the EDARADD gene, which encodes a protein that interacts with the EDA receptor. [6]Hidrotic ED (Clouston syndrome), which is an autosomal dominant disorder, is caused by mutations in GJB6, which encodes connexin 30, a component of intercellular gap junctions.Hay-Wells syndrome (ankyloblepharon filiforme adnatum), Rapp-Hodgkin syndrome and EEC (Ectrodactly-ectodermal dysplasia) syndrome are all caused by mutations in the TP73L (p63) gene, featuring congenital abnormalities of skin, hair, teeth, nail, eccrine and mucous glands, as well as cleft deformities.The genetic defects underlying several other EDs are also known. [2]Palmoplantar keratoderma with deafness is caused by mutations in the GJB26 gene, which encodes connexin 26.Margarita Island ED is caused by mutations in the PVRL1 gene, which encodes nectin-1.ED with skin fragility is caused by mutations in the PKP1 gene, which encodes plakophilin 1.Hypotrichosis with juvenile macular dystrophy is caused by mutations in the CDH3 gene, which encodes p-cadherin.ADULT syndrome is caused by mutations in the TP63 gene.Split hand-foot malformation syndrome is caused by mutations in the TP63 gene.Limb-mammary syndrome is caused by mutations in the TP63 gene.Radiographs

Orthopantomogram at an early age is to be done to rule out hypodontia and dental abnormalities. [7]

X-rays of the hand, feet show specific skeletal deformities. Renal ultrasonography, pilocarpine iontophoresis and skin biopsy may document hypohidrosis and a reduction in the number of eccrine glands. [2]

Other diagnostic tests

Sweat pore count

Sweat pore count is done using yellow starch-iodine powder applied to palmar or dorsal skin. In unaffected persons, sweating turns the powder to deep purple, allowing visualization of sweat pores. Sweat pores are poorly visualized in affected children [8] [Figure 6]a and b.

Blaschko lines

Streaky areas of hypohidrosis that follow Blaschko lines [9] are observed upon starch-iodine staining, which demonstrates a mosaic pattern of areas of normal numbers of sweat pores alternating with areas of absent pores [Figure 7]a and b.

Skin biopsy

Hypothenar eminence is the most reliable biopsy site to demonstrate an absence or hypoplasia of sweat glands. [2]

Prenatal diagnosis

Fetal skin biopsy helps in the diagnosis of prenatal ED.

Chorionic villus sampling at the 10 th week of gestation can be done for some EDs. [2]

Histologic findings

Skin histopathology documents a reduction in the number of sweat glands, hair follicles and sebaceous glands associated with the different EDs. In EDA, the epidermis is thin and flattened. Eccrine sweat glands are few or poorly developed or are very rudimentary. Salivary glands may show ectasia of ducts and inflammatory changes. [3]


Ectodermal dysplasia is a genetic disorder affecting the ectodermal structures, typically involving hair, nail, skin, sweat glands and dental anomalies such as hypodontia or microdontia. Clinicians should consider ED as a differential diagnosis in patients having anomalies of tooth form, structure or number. Various diagnostic tests mentioned above can aid in the confirmation of the diagnosis. Although restorative management may be challenging, the importance of basic prevention should be stressed.[Figure 1],[Figure 2],[Figure 3],[Figure 4],[Figure 5]


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