Acrodermatitis enteropathica without hypozincemia

Zinc and infant nutrition

Zinc is essential for a wide variety of cellular processes in all cells. It is a critical dietary nutrient, particularly in the early stages of life. In the early neonatal period, adequate sources of zinc can be obtained from breast milk. In rare circumstances, the mammary gland produces zinc deficient milk that is potentially lethal for exclusively breast-fed infants. This can be overcome by zinc supplementation to the infant. Alterations to key zinc transporters provide insights into the mechanisms of cellular zinc homeostasis. The bioavailability of zinc in food depends on the presence of constituents that may complex zinc. In many countries, zinc deficiency is a major health issue due to poor nourishment. Young children are particularly affected. Zinc deficiency can impair immune function and contributes to the global burden of infectious diseases including diarrhoea, pneumonia and malaria. Furthermore, zinc deficiency may extend its influence across generations by inducing epigenetic effects that alter the expression of genes. This review discusses the significance of adequate zinc nutrition in infants, factors that influence zinc nutrition, the consequences of zinc deficiency, including its contribution to the global burden of disease, and addresses some of the knowledge gaps in zinc biology.

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.

Diaper dermatitis: a review and update

PURPOSE OF REVIEW

Diaper dermatitis is the most common cutaneous diagnosis in infants. In this review, common causes of diaper dermatitis and similarly presenting conditions will be covered, as well as updates on treatments of common diaper dermatitides.

RECENT FINDINGS

There have been recent advancements in the treatment of diaper dermatitis. In addition, there are many newly recognized causes of diaper dermatitis that clinicians should be aware of.

SUMMARY

Irritant dermatitis is the most common cause of diaper dermatitis. However, there are multiple other common causes of diaper dermatitis and it is thus imperative that the clinician be aware of cutaneous mimickers of irritant diaper dermatitis as well as their treatments.

A case of acrodermatitis enteropathica localized on the hands and feet with a normal serum zinc level

Acrodermatitis enteropathica is classified as a congenital autosomal recessive type and an acquired transient type. This disease manifests as acral and periorificial dermatitis, alopecia, intractable diarrhea, and failure to thrive. Whereas the autosomal hereditary type is caused by malabsorption of zinc in the intestine, the acquired type is caused by low nutritional support or decreased peripheral release of zinc from blood. We experienced a case of a 5-month old, breast feeding, full-term female presenting with only acral bullous dermatitis without diarrhea, periorificial dermatitis and an abnormal serum zinc level.

A diagnostic challenge: a case of acrodermatitis enteropathica without hypozincemia and with maternal milk of low zinc level

Acrodermatitis enteropathica is a rare and distinct form of zinc deficiency with a requirement of life-long zinc supplementation and inherited in a recessive manner. Transient nutritional zinc deficiency is also a well known condition mimicking acrodermatitis enteropathica like skin changes in preterm and term infants who are generally breastfed with a low level of zinc containing milk. Here, a 4-month-old male, term and fully breastfed acrodermatitis enteropathica case without hypozincemia and with maternal milk of low zinc level is presented.

Acrodermatitis enteropathica: case report and review of the literature

Acrodermatitis enteropathica (AE) is a rare hereditary disorder caused by impaired absorption of zinc from the gastrointestinal tract. It is characterized by acral and periorificial dermatitis, alopecia, and diarrhea. Symptoms usually begin on weaning from breast or formula feeding. We report a full-term, 21-month-old boy with typical skin lesions and decreased plasma zinc level (12 micro g/dl). The patient was given zinc sulfate 40 mg/day and at the end of 1 month his condition had improved significantly. After reviewing the literature we emphasize the important role of zinc in human metabolism and the difference between AE and acquired zinc deficiencies.

Chronic diarrhea and malabsorption

Diarrhea is one of the major causes of infant morbidity and mortality worldwide. Major advances in understanding the pathophysiology of chronic diarrhea and malabsorption have taken place during the past three decades. Analysis of absorptive and secretory functions of the intestine has provided some insight into the possible causes of diarrhea. This article summarizes some of the specific causes of malabsorptive diarrhea in infancy and childhood, with emphasis on pathophysiology and approaches to therapy.

The effect of the acrodermatitis enteropathica mutation on zinc uptake in human fibroblasts

The acrodermatitis enteropathica (AE) mutation affects intestinal zinc absorption. Our goal was to determine whether the AE mutation affects zinc uptake in human fibroblasts. Zinc uptake was determined during initial rates of uptake (10 min) following incubation in HEPES/saline buffer. Zinc uptake (from 0.25 to 1 microM) into normal fibroblasts was significantly greater than into the AE fibroblasts (p < 0.05). In order to identify factors that may alter cellular zinc uptake and be affected by the AE mutation, zinc uptake in the presence of albumin or bicarbonate was measured. Albumin restricted zinc uptake in both normal and AE fibroblasts, whereas bicarbonate stimulated zinc uptake in the normal fibroblasts. The effect of bicarbonate on zinc uptake in the AE fibroblasts was significantly reduced in both the Pronase-sensitive and Pronase-resistant compartments. Following loading of the fibroblasts with 1 microM zinc for 60 min, zinc efflux and retention were measured. The AE mutation did not affect zinc retention compared to normal fibroblasts. We conclude that the AE mutation affects both zinc binding to the cell surface and its translocation across the plasma membrane into the cell, possibly mediated through a defective anionic exchange mechanism.

Can topical zinc accentuate tuberculin reactivity in the elderly?

We examined the effect of topical zinc on Heaf tests in 58 elderly hospitalized patients in a double-blind study. Plasma zinc levels were measured. Thirty-eight subjects (66%) had negative reactions with placebo ointment. Fourteen of these negative responders (37%) had positive reactions with topical zinc ointment; 12 (32%) had weakly positive reactions and 12 remained negative. There was no significant difference in the plasma zinc levels between the different grades of topical zinc effect in the negative responders. Zinc deficiency is therefore unlikely to account for the observed booster effect of topical zinc on tuberculin reactivity.

The measurement of exchangeable pools of zinc using the stable isotope 70Zn

The present study was designed to assess the feasibility of using small doses of a stable isotope of Zn to follow plasma kinetics over a 10 d period and, hence, make deductions about Zn turnover and body pool sizes. At the beginning of the 10 d metabolic balance, two adults, consuming their habitual diet, were given an intravenous injection of 70Zn. There was a fourfold difference in the administered dose between the two subjects (0.445 and 2.078 mg). Blood samples were taken at regular intervals and plasma enrichment with 70Zn measured by thermal ionization mass spectrometry. Urine and faeces were collected and analysed for Zn and 70Zn. Kinetic analysis of the plasma 70Zn decay by several different methods was undertaken. It was apparent from both deconvolution analysis of the short-term (0-90 min) decay data and four-compartment modelling of the longer-term (0-24 h) data that isotopic Zn very rapidly equilibrates with the plasma Zn and with a rapidly exchanging non-plasma pool, probably located within the liver. This latter pool appears to contain less than 10 mg Zn and the peak of isotope enrichment occurs at about 20 min post injection. The later decay of plasma Zn enrichment appears to be dictated by exchange with a much larger pool of approximate size 350 mg.

Acrodermatitis enteropathica with normal serum zinc levels: diagnostic value of small bowel biopsy and essential fatty acid determination

We report a patient with acrodermatitis enteropathica and a normal serum zinc level in whom the diagnosis was confirmed by plasma phospholipid fatty acid and a small bowel biopsy response to oral zinc therapy. Acrodermatitis enteropathica is a rare autosomal recessive condition of zinc deficiency characterised by chronic diarrhoea associated with failure to thrive, periorificial dermatitis and alopecia, susceptibility to infections and behavioural changes. Diagnosis is usually established by reduced serum zinc levels (classical acrodermatitis enteropathica). Paneth cell abnormalities on electron microscope of a small bowel biopsy can be supportive. A few cases with the typical picture of acrodermatitis enteropathica without hypozincaemia (variant acrodermatitis enteropathica) have been described. The diagnosis of variant acrodermatitis enteropathica to date has been based on an entirely empiric, but nonetheless convincing clinical response to oral zinc therapy. Laboratory aids to diagnosis have been lacking.

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.

Leukocyte zinc in the assessment of zinc status

The problems of assessment of human zinc status are reviewed, with particular emphasis on the limitations to each of the current available measurements. The advantages and limitations of leukocytes are then described. Methods of preparation and potential problems in the assay for zinc are described in detail. The data so-far produced by this method are reviewed.

Alopecia and periorificial dermatitis in biotin-responsive multiple carboxylase deficiency

Three siblings with infantile-onset biotin-responsive multiple carboxylase deficiency are described. Recognition of the characteristic dermatologic manifestations, alopecia and periorificial dermatitis, should result in early diagnosis and institution of potentially lifesaving therapy with biotin. Other metabolic disorders may present a similar clinical picture. Immunologic dysfunction and/or aberration in lipid or branched chain amino acid metabolism may be the common pathophysiologic link in some or all of these disorders.

Acrodermatitis enteropathica

A brief review of the clinical and biochemical features of Acrodermatitis enteropathica is given. This condition in now known to be caused by a systemic zinc deficiency secondary to a defect in the intestinal absorption of zinc and it illustrates the metabolic importance of this element in man.

The role of dietary ergothioneine in the development of diabetes mellitus

Ergothioneine is believed not to be synthesized by man but it accumulates to high concentrations in some mammalian cells as a result of dietary intake. Ergothioneine is known to chelate divalent metal ions with high affinity. Other substances which are potent chelators of divalent metal ions such as diphenylthiocarbazone and quinaldic acid are known to be potent diabetogenic agents. It is therefore likely that because of its high concentration in man and its high affinity for divalent cations, ergothioneine is a naturally occurring chelating agent which can be a contributing factor leading to the development of diabetes mellitus in some individuals. In one study it has been shown that some diabetic patients have markedly elevated levels of ergothioneine compared with normal individuals. The mechanism by which ergothioneine induces diabetes may be through its chelation of zinc which is important for the storage of insulin and glucagon.

Acrodermatitis enteropathica and the relation to pellagra

A patient with a variant form of acrodermatitis enteropathica (AE) without hypozincemia is presented who showed a rise in plasma zinc and partial improvement on a pancreatic enzyme preparation, apparently because of its content of picolinic acid (PA). Complete recovery occurred on 60 mg zinc (1). This patient has now been treated with zinc PA (equal to only 5 mg zinc) and subsequently with PA. Both maintained elevated plasma zinc levels. Because of the similarity of AE with pellagra and the common origin of PA and nicotinic acid from tryptophan, a hypothesis is presented which suggests that skin manifestations in the two disorders are due to PA deficiency since picolinic carboxylase forms NAD preferentially when there is competition for the common precursor.

Possible role of prostaglandin E1 in the affective disorders and in alcoholism

Prostaglandin (PG)E1 may play an important part in the affective disorders, with an excess being present in mania and a deficiency in depression. Platelets from manic patients produce more PGE1 than normal while those from depressive patients produce less. Ethyl alcohol stimulates PGE1 production whereas lithium inhibits it. Alcoholics will tend to have raised PGE1 concentrations while drinking, but, because precursor supplies are limited, when alcohol concentrations fall PGE1 concentrations may fall sharply leading to depression. PGE1 biosynthesis may be affected by nutritional factors including essential fatty acids, pyridoxine, vitamin C, and zinc. Nutritional approaches may be of value in both depression and alcoholism.

Myotonic dystrophy: a disease caused by functional zinc deficiency due to an abnormal zinc-binding ligand?

There are large amounts of zinc in muscle and zinc ions can enhance the degree of muscle contraction in response to direct stimulation while at the same time inhibiting neuromuscular transmission. The opposites of these effects would lead to myotonia and muscle weakness. There are many parallels between the non-muscular features of myotonic dystrophy and those of zinc deficiency. The particular patterns of reproductive disturbance in both males and females, the abnormalities of metabolism, the defects in gut funcion, the defects in bone and the congenital abnormalities are very similar in the two conditions. However there are important differences between simply zinc deficiency states and myotonic dystrophy which mean that the latter is unlikely to be due to the former. Instead it is proposed that the fundamental defect in myotonic dystrophy is the presence of an abnormal zinc binding ligand which fails to deliver appropriate amounts of zinc ions to the tissues. The functioning of this ligand may, however, be affected by dietary zinc, perhaps accounting for the apparent variation in the expression of the dominant myotonic dystrophy gene due to some unknown environmental factor. Some of the effects of zinc may be due to lack of the zinc ion directly, while others are probably related to defects in essential fatty acid and prostaglandin metabolism. The hypothesis can be readily tested by the employment of nutritional measures designed to counteract the defects in zinc and essential fatty acid metabolism.

Interactions between zinc, essential fatty acids and prostaglandins: relevance to acrodermatitis enteropathica, total parenteral nutrition, the glucagonoma syndrome, diabetes, anorexia nervosa and sickle cell anaemia

Many of the features of zinc deficiency and of essential fatty acid (EFA) deficiency are similar in both animals and humans. The two agents interact in various ways. EFAs are important in zinc absorption, probably after conversion to prostaglandins (PGs). Zinc seems necessary for at least two stages in EFA metabolism, the conversion of linoleic acid to gamma-linolenic acid, and the mobilisation of dihomogammalinolenic acid (DGLA) for the synthesis of 1 series PGs. Zinc may also be important in the conversion of DGLA to arachidonic acid and in arachidonic acid mobilisation for 2 series PG formation. These interactions shed considerable light on a number of clinical syndromes, including acrodermatitis enteropathica, total parenteral nutrition, diabetes mellitus, the glucagonoma syndrome and sickle cell anaemia. There is substantial evidence to suggest that anorexia nervosa is due to a combined deficiency of zinc and EFAs. Understanding of the roles of zinc and EFAs in these various clinical situations is likely to lead to improved therapy.

Acrodermatitis enteropathica without hypozincemia: therapeutic effect of a pancreatic enzyme preparation due to a zinc-binding ligand

The clinical course and intestinal absorption studies of a female infant who developed diarrhea after cessation of breast feeding, mood changes, and intermittently had mild perioral and perianal rashes are described. She showed a partial response to a pancreatic enzyme preparation which was attributed to its content of a zinc-binding ligand, picolinic acid. Complete recovery occurred on pharmacologic doses of zinc. Exacerbation occurred twice upon withdrawal of the oral zinc medication. The zinc concentrations of plasma and intestinal mucosa were normal.

Behavioral and dermatologic changes and low serum zinc and copper concentrations in two premature infants after parenteral alimentation

Two premature infants were observed to develop behavioral and dermatologic changes and low serum zinc and copper concentrations following cessation of prolonged parenteral alimentation, while being fed exclusively with human milk. Following treatment with exogenous oral zinc supplementation, prompt relief of symptoms and increases of serum zinc and copper concentrations were observed in both infants. These patients comprise about 5% of our premature infants who are treated with parenteral alimentation for more than two weeks. We recommend that premature infants on prolonged parenteral alimentation should be monitored for changes in serum zinc and copper concentrations and, if a marked fall is observed, supplementation should be considered.

Zinc and immunocompetence in protein-energy malnutrition

Malnourished children have thymic atrophy which is reversed by zinc supplementation. To see if their defect in cell-mediated immunity was also associated with zinc deficiency ten children were skin-tested with Candida antigen on both arms. One test site was covered with local zinc sulphate and the other with placebo ointment. There was a highly significant increase in the typical delayed-hypersensitivity reaction at the site covered with zinc. The magnitude of the difference between the supplemented and unsupplemented arms correlated negatively with the plasma-zinc concentration. These data show that zinc deficiency is a cause of the immunoincompetence seen in malnutrition. The normal reactions of the zinc-supplemented side indicate that, of the many nutritional deficits of malnourished children, zinc deficiency specifically impairs the cell-mediated immune system. Local skin-testing with and without zinc may provide a measure of zinc status. Local application of zinc may enhance the reliability of tests to diagnose diseases such as tuberculosis in malnourished patients.