Acrodermatitis Enteropathica

Updated: Oct 03, 2017
  • Author: Kristina Marie Dela Rosa, MD; Chief Editor: William D James, MD  more...
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Overview

Background

Acrodermatitis enteropathica is a rare inherited form of zinc deficiency, characterized by periorificial and acral dermatitis, alopecia, and diarrhea.

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Pathophysiology

Zinc is an essential trace nutrient required for the proper function of more than 100 enzymes and plays a crucial role in nucleic acid metabolism. [1, 2]

Acrodermatitis enteropathica is an autosomal recessive disorder postulated to occur as a result of mutations in the SLC39A4 gene located on band 8q24.3. [3, 4, 5] The SLC39A4 gene encodes a transmembrane protein that is part of the zinc/iron-regulated transporter–like protein (ZIP) family required for zinc uptake. [6, 7] This protein is highly expressed in the enterocytes in the duodenum and jejunum [8, 9] ; therefore, affected individuals have a decreased ability to absorb zinc from dietary sources. Absence of a binding ligand needed to transport zinc may further contribute to zinc malabsorption. [10]

Differentiating acquired zinc deficiency disorders from acrodermatitis enteropathica is difficult because they have similar clinical presentations. Acquired zinc deficiency can occur as a result of low nutritional intake, malabsorption, excessive loss of zinc, or a combination of these factors. [11] Acrodermatitis enteropathica can only be accurately diagnosed after attempts to remove zinc supplementation have failed. [12] Importantly, transient acquired zinc deficiencies can occur in premature infants secondary to their greater physiological demand for zinc and lower body stores. [13, 14] Additionally, zinc deficiency can present in full-term breastfed infants as a result of low maternal serum zinc levels or a defect in mammary zinc secretion. [1, 15] Thus, not all infants who have an acrodermatitis enteropathica–like presentation have the genetic disorder. Also see the Pediatrics article Acrodermatitis Enteropathica.

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Etiology

The etiopathogenesis of the zinc deficiency is postulated to occur as a result of a mutation in a zinc transport protein encoded by the SLC39A4 gene and perhaps alteration in a zinc transport ligand. [16]   However, a case was reported of a patient with a new mutation of SLC39A4 who had normal zinc levels and a milder phenotype. [17]

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Epidemiology

Frequency

United States

The frequency of acrodermatitis enteropathica is unknown.

International

An estimated 1 in 500,000 people in Denmark are affected by acrodermatitis enteropathica. [18]

Race

Acrodermatitis enteropathica has no racial predilection.

Sex

Acrodermatitis enteropathica has no sexual predilection.

Age

Acrodermatitis enteropathica typically appears in the first few weeks after birth if the child is fed bovine milk or shortly after cessation of breastfeeding. [9] Acrodermatitis enteropathica can occur in children who are still breastfeeding if the levels of zinc are low in the breast milk. [19]

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Prognosis

With zinc supplementation, the response rate is 100%; however, without appropriate zinc supplementation, acrodermatitis enteropathica usually is lethal within the first few years of life. Untreated infants exhibit severe growth retardation, dermatitis, alopecia, secondary bacterial and fungal infections, and neurologic and behavioral changes; however, all symptoms are reversible with therapy.

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Patient Education

In the future, genetic counseling with genetic testing may be available for siblings at risk for acrodermatitis enteropathica.

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