Published on 18/03/2015 by admin
Filed under Dermatology
Last modified 18/03/2015
This article have been viewed 1969 times
Joanna E. Gach
Evidence Levels: A Double-blind study B Clinical trial ≥ 20 subjects C Clinical trial < 20 subjects D Series ≥ 5 subjects E Anecdotal case reports
(Courtesy of Shyam B. Verma.)
Acrodermatitis enteropathica (AE) is a rare, autosomal recessive inherited disorder of zinc deficiency. It is caused by mutations in the SLC39A gene located on 8q24.3, which encodes for Zip4 intestinal zinc transporter expressed in enterocytes that absorb dietary zinc from the small intestine. The estimated prevalence is 1 in 500 000 children worldwide, without apparent predilection for race or gender. AE manifests itself shortly after birth in a bottle-fed infant, and sometime soon after weaning in a breastfed infant. Zinc within breast milk is more bioavailable to infants rather than bovine milk due to binding to a low molecular weight ligand secreted by the pancreas. Characteristic clinical signs are lesions in acral and periorificial sites; the first signs are eczematous, pink scaly plaques that can become vesicular, bullous, pustular or desquamative. They can resemble the severe diaper dermatitis of infancy. Angular cheilitis and paronychia can also be seen early. If left untreated, AE usually causes diarrhea, irritability, and alopecia, and skin lesions become secondarily infected with bacteria and Candida albicans. Impaired physical and mental development is seen in advanced disease. Appropriate supplementation of zinc in the infant’s diet results in a rapid improvement.
The diagnosis of AE is applied only to inherited zinc deficiency; non-inherited zinc deficiency is called acquired zinc deficiency. Long-term therapy and management of zinc deficiency vary depending on the severity of the disorder.
Chronic dermatitis in periorificial and acral areas should suggest the possibility of zinc deficiency, but establishing the diagnosis of AE may be difficult. The first step is laboratory determination of blood plasma or serum zinc levels. Blood sample needs to be drawn into a trace element-free bottle with a stainless steel needle. Avoid contact with rubber stoppers as they contain zinc, avoid hemolysis, use zinc-free anticoagulants, separate plasma or serum from cells within 45 minutes. Zinc levels will decrease in states of hypoalbuminemia because zinc binds albumin in the circulation. If the diagnosis of zinc deficiency has been confirmed, management becomes relatively simple: oral zinc supplementation produces dramatic resolution of the problem. High dose supplementation will allow for increased paracellular zinc absorption despite the absence of a functional Zip4 zinc transporter.
Treatment of Skin Disease Comprehensive Therapeutic Strategies 4e
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