Ectodermal dysplasia
| Ectodermal dysplasia | |
|---|---|
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| Ectodermal dysplasia, this image shows peg shaped teeth, coarse, sparse hair | |
| Classification and external resources | |
| Specialty | medical genetics |
| ICD-10 | Q82.4 |
| ICD-9-CM | 757.31 |
| DiseasesDB | 30597 |
| MedlinePlus | 001469 |
| eMedicine | derm/114 |
| MeSH | D004476 |
Ectodermal dysplasia is not a single disorder, but a group of syndromes all deriving from abnormalities of the ectodermal structures. More than 150 different syndromes have been identified.
Despite some of the syndromes having different genetic causes the symptoms are sometimes very similar. Diagnosis is usually by clinical observation often with the assistance of family medical histories so that it can be determined whether transmission is autosomal dominant or recessive.
Worldwide around 7,000 people have been diagnosed with an ectodermal dysplasia condition. Some ED conditions are only present in single family units and derive from very recent mutations. Ectodermal dysplasias can occur in any race but are much more prevalent in caucasians than any other group and especially in fair caucasians.
Ectodermal dysplasias are described as "heritable conditions in which there are abnormalities of two or more ectodermal structures such as the hair, teeth, nails, sweat glands, salivary glands, cranial-facial structure, digits and other parts of the body."
Individuals affected by an ED syndrome frequently have abnormalities of the hair follicles. Scalp and body hair may be thin, sparse, and very light in color, even though beard growth in affected males may be normal. The hair may grow very slowly or sporadically and it may be excessively fragile, curly, or even twisted.
Fingernails and toenails may be thick, abnormally shaped, discolored, ridged, slow-growing, or brittle. The cuticles may be prone to infections.
The skin may be lightly pigmented. Skin sustaining injury may grow back permanently hypo-pigmented. In some cases, red or brown pigmentation may be present. Skin can be prone to rashes or infections and can be thick over the palms and soles. Care must be taken to prevent cracking, bleeding, and infection.
Individuals affected by certain ED syndromes cannot perspire. Their sweat glands may function abnormally or may not have developed at all because of inactive proteins in the sweat glands. Without normal sweat production, the body cannot regulate temperature properly. Therefore, overheating is a common problem, especially during hot weather. Access to cool environments is important.
Several studies have examined salivary flow rate in individuals and found parotid and submandibular salivary flow ranging from 5 to 15 times lower than average. This is consistent with the salivary glands being of ectodermal origin, although some findings have suggested that there is also mesodermal input.
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