Zinc

Bluish-white metal that plays a role in dermatology for zinc deficiency dermatoses. Zinc is also used in the form of zinc oxide as a component of powders, shaking mixtures, oils(zinc oil) or pastes(zinc paste) with various indications.

Zinc deficiency: The incidence of inherited zinc deficiency worldwide is 1/500,000 inhabitants.

Standard values: The reference range in serum and plasma is between 9 and 21 µmol/l, in whole blood between 60 and 115 µmol/l

Pathologically low: alcoholism, diabetes mellitus, infections, chronic liver diseases, nephrotic syndrome, malnutrition, malassimilation, acrodermatitis enteropathica, rheumatic diseases

Pathologically elevated: excessive zinc intake

Dietary sources of zinc are 33% from meat and meat products, 25% from milk, dairy products and eggs, 20% from cereal products and 20% from other sources.

Dietary zinc deficiency is a rarity, affecting developing countries and strict vegetarians.

In acrodermatitis enteropathica, the congenital, autosomal recessive inherited, primary zinc absorption disorder (gene locus 8q24.3) is discussed, caused by the absence of a zinc binding factor (soluble carrier SLC39A4) in the small intestine, which is present in breast milk but not in cow's milk and leads to a drop in zinc absorption to 2-3% of the normal value.

1. Maverakis et al (2007) Acrodermatitis enteropathica and an overview of zinc metabolism. J Am Acad Dermatol 56: 116-124