Etiology

• The genetic defect appears to involve SLC39A4 on chromosome 8q
• This gene appears to encode a transmembrane protein that serves as a zinc uptake protein
• Symptoms occur within the first few months after birth and tend to appear shortly after discontinuation of breastfeeding
• This phenomenon has led many to believe that human milk has a beneficial ligand, which bovine milk lacks

Signs and symptoms

• There are erythematosus patches and plaques of dry, scaly skin.
• The lesions may appear eczematous, or may evolve further into crusted vesicles , bullas or pustules.
• The lesions are frequent around the mouth and anus, and also in hands, feet and scalp. There may be suppurative inflammation of the nail foldnail plate - known as paronychia.
  
• Alopecia - loss of hair from scalp, eyebrows and eyelashes may occur.
• The skin lesions may be secondarily infected by bacteria such as Staphylococcus aureus or fungi like Candida albicans.
• These skin lesions are accompanied by diarrhea.

Tests and diagnosis

Plasma zinc levels are low.

Determining hair, urine, and parotid saliva zinc levels as well as serum alkaline phosphatase activity (which lowers later in the disease) may be helpful.

Analysis of maternal breast milk zinc concentrations may also help in differentiating AE from acquired zinc deficiency

Treatment

Without treatment, the disease is fatal and affected individuals may die within a few years. There is no cure for the condition.

Lifelong dietary zinc supplementation in the range of greater than 1-2 mg/kg of bodyweight per day.