Acrodermatitis enteropathica

Zinc deficiency and its inherited disorders -a review

Zinc is an essential trace element required by all living organisms because of its critical roles both as a structural component of proteins and as a cofactor in enzyme catalysis. The importance of zinc in human metabolism is illustrated by the effects of zinc deficiency, which include a diminished immune response, reduced healing and neurological disorders. Furthermore, nutritional zinc deficiency can be fatal in newborn or growing animals. While zinc deficiency is commonly caused by dietary factors, several inherited defects of zinc deficiency have been identified. Acrodermatitis enteropathica is the most commonly described inherited condition found in humans. In several of the few cases that have been reported, this disorder is associated with mutations in the hZIP4 gene, a member of the SLC39 family, whose members encode membranebound putative zinc transporters. Mutations in other members of this family or in different genes may account for other cases of acrodermatitis in which defects in hZIP4 have not been detected. Another inherited form of zinc deficiency occurs in the lethal milk mouse, where a mutation in ZnT4 gene, a member of the SLC30 family of transmembrane proteins results in impaired secretion of zinc into milk from the mammary gland. A similar disorder to the lethal milk mouse occurs in humans. In the few cases studied, no changes in ZnT4 orthologue, hZnT4, were detected. This, and the presence of several minor phenotypic differences between the zinc deficiency in humans and mice, suggests that the human condition is caused by defects in genes that are yet to be identified. Taking into account the fact that there are no definitive tests for zinc deficiency and that this disorder can go undiagnosed, plus the recent identification of multiple members of the SCL30 and SLC39, it is likely that mutations in other genes may underlie additional inherited disorders of zinc deficiency.

Bullous lesions in acrodermatitis enteropathica delaying diagnosis of zinc deficiency: a report of two cases and review of the literature

Acrodermatitis enteropathica (AE) is a rare disorder associated with poor absorption of zinc. A variety of clinical and histological findings have been reported in the literature, described mainly in isolated case reports. Because of the varied nature of these cases, the histological features of AE are described often as non-specific. We describe lesions of AE in two patients who presented with vesiculobullous and erosive skin lesions, both showing intra-epidermal, inflammatory vesiculation with surrounding eosinophilic epidermis and necrotic keratinocytes. The lack of clinical suspicion of AE led to their misdiagnosis. We present these two patients to further characterize the bullous variant of AE, and we review the previously reported clinical and histopathological findings.

Metabolic diseases and pregnancy

The skin mirrors the hormonal metabolic and physiologic changes that occur during pregnancy. The metabolic effects are manifested primarily in accentuation of two disorders, porphyria cutanea tarda and acrodermatitis enteropathica. The former may be exacerbated, not only during pregnancy, but also during the post-partum period and with the intake of estrogen-containing birth control pills. Exacerbations of acrodermatitis enteropathica characteristically appear during pregnancy.

Dermatoses of pregnancy

The dermatoses of pregnancy can be classified into the following 3 groups: physiologic skin changes in pregnancy, dermatoses and cutaneous tumors affected by pregnancy, and specific dermatoses of pregnancy. Correct diagnosis and classification are essential for the treatment of these disorders, when necessary. Laboratory investigations are required when the diagnosis remains in question despite a careful history and thorough physical examination. A discussion with the pregnant woman about the nature of her skin condition, and the possible fetal risks associated with it, is imperative.

Clinical response of alopecia, trichorrhexis nodosa, and dry, scaly skin to zinc supplementation

Two unrelated patients had dry brittle hair, alopecia, trichorrhexis nodosa, dry scaly skin, pigment dyschromia, short stature, and neurosecretory growth hormone deficiency. By means of the zinc tolerance test, patient 1 was shown to have zinc deficiency, whereas no clear zinc deficiency could be demonstrated in patient 2. In both patients, hair and the skin abnormalities responded to oral zinc therapy.

Acquired zinc deficiency in association with anorexia nervosa: case report and review of the literature

Zinc deficiency, whether a result of an acquired or inherited abnormality of zinc metabolism, is associated with characteristic cutaneous findings. The inherited variety is known as acrodermatitis enteropathica. We present a case of zinc deficiency secondary to starvation induced by anorexia nervosa. Since the cutaneous stigmata of zinc deficiency and anorexia nervosa can initially be subtle and occasionally overlap, we believe that screening zinc levels in patients with anorexia nervosa with prominent cutaneous findings should be considered.

Clinical and laboratory diagnosis of acrodermatitis enteropathica

Acrodermatitis enteropathica is an inborn error of metabolism resulting in zinc malabsorption and severe zinc deficiency. From personal experience and a literature review the following conclusions were drawn: 1. Symptoms other than dermatitis, vary with age. Diarrhoea, mood changes, anorexia, and neurological disturbance were reported most frequently in infancy. Growth retardation, alopecia, weight loss and recurrent infections were prevalent in toddlers and schoolchildren. Spontaneous remission may occur at adolescence. 2. The severity of symptoms also varies. Intermittent or mild cases of the disease and those presenting with uncommon features such as ophthalmic, cerebral or hepatic involvement, are easily overlooked. In the severe cases this may result in a fatal outcome. If untreated, the overall mortality rate is 20%, being higher in males. 3. The laboratory diagnosis is hazardous. In patients, mean zinc values in serum, urine and hair were ca. 50% of normal levels. There is a 15% overlap with healthy controls; moreover, low zinc levels in serum, urine or hair are also found in other diseases. A more specific test is required. 4. In cases of doubt, in vitro or in vivo zinc absorption tests using radioisotopes (65Zn or 69mZn) may be performed. These appear not to be influenced by other conditions and show less overlap with controls. If such tests are unavailable, the clinical response to 3-30 mumol zinc/kg per day for 5 days may be awaited. This is recommended in infants or children with one or more symptoms of acrodermatitis enteropathica.

Nutritional deficiency and the skin

Cutaneous changes occur in deficiency states of many nutritional elements: ascorbic acid, retinol, protein-energy, cyanocobalamin, phytonadione (vitamin K), biotin, ribroflavin, pyridoxine, niacin, essential fatty acids, and zinc. There are also inherited disorders of copper, biotin, zinc, and tryptophan metabolism. Cutaneous vitamin D synthesis is inhibited by sunscreen use. The striking skin changes of the glucagonoma syndrome may be related to nutritional pathways.

Skin diseases aggravated by pregnancy

During pregnancy, immunologic, endocrine, metabolic, and vascular changes occur that make the pregnant woman susceptible to aggravation of certain skin diseases. These diseases can be organized into five broad categories: infections, diseases of altered immunity, metabolic diseases, connective tissue disorders, and miscellaneous conditions. A discussion of how each of these diseases is altered by pregnancy and how treatment may differ during gestation is presented.