Acrodermatitis enteropathica-like cutaneous lesions in organic aciduria

Pathophysiological mechanisms of complications associated with propionic acidemia

Propionic acidemia (PA) is a genetic metabolic disorder caused by mutations in the mitochondrial enzyme, propionyl-CoA carboxylase (PCC), which is responsible for converting propionyl-CoA to methylmalonyl-CoA for further metabolism in the tricarboxylic acid cycle. When this process is disrupted, propionyl-CoA and its metabolites accumulate, leading to a variety of complications including life-threatening cardiac diseases and other metabolic strokes. While the clinical symptoms and diagnosis of PA are well established, the underlying pathophysiological mechanisms of PA-induced diseases are not fully understood. As a result, there are currently few effective therapies for PA beyond dietary restriction. This review focuses on the pathophysiological mechanisms of the various complications associated with PA, drawing on extensive research and clinical reports. Most research suggests that propionyl-CoA and its metabolites can impair mitochondrial energy metabolism and cause cellular damage by inducing oxidative stress. However, direct evidence from in vivo studies is still lacking. Additionally, elevated levels of ammonia can be toxic, although not all PA patients develop hyperammonemia. The discovery of pathophysiological mechanisms underlying various complications associated with PA can aid in the development of more effective therapeutic treatments. The consequences of elevated odd-chain fatty acids in lipid metabolism and potential gene expression changes mediated by histone propionylation also warrant further investigation.

A Case of Acrodermatitis Dysmetabolica in a Child Affected by Citrullinemia Type I: When Early Diagnosis and Timely Treatment Are Not Enough

An infant with a prenatal diagnosis of citrullinemia, who started standard treatment at birth (L-arginine; sodium benzoate and a personalized diet characterized by a low protein intake and supplementation of essential nutrients and amino acids), presented at 4 months of age with extended, progressive, and severe skin lesions consistent with acrodermatitis dysmetabolica. Guidelines for the diagnosis and management of urea cycle disorders underline that a low-protein diet places patients at risk of essential fatty acids, trace elements, and vitamin deficiency. At hospital admission, our patient had normal levels of zinc and alkaline phosphatases. The plasmatic amino acid profile revealed a severe and generalized deficiency. In particular, the serum levels of arginine, valine, and isoleucine were very low and the dermatitis did not improve until the blood levels of these amino acids increased. In our patient, skin lesions happened despite an early diagnosis of citrullinemia and timely treatment due to compliance issues as a consequence of linguistic barriers.

Pathophysiology of propionic and methylmalonic acidemias. Part 1: Complications

Over the last decades, advances in clinical care for patients suffering from propionic acidemia (PA) and isolated methylmalonic acidemia (MMA) have resulted in improved survival. These advances were possible thanks to new pathophysiological insights. However, patients may still suffer from devastating complications which largely determine the unsatisfying overall outcome. To optimize our treatment strategies, better insight in the pathophysiology of complications is needed. Here, we perform a systematic data-analysis of cohort studies and case-reports on PA and MMA. For each of the prevalent and rare complications, we summarize the current hypotheses and evidence for the underlying pathophysiology of that complication. A common hypothesis on pathophysiology of many of these complications is that mitochondrial impairment plays a major role. Assuming that complications in which mitochondrial impairment may play a role are overrepresented in monogenic mitochondrial diseases and, conversely, that complications in which mitochondrial impairment does not play a role are underrepresented in mitochondrial disease, we studied the occurrence of the complications in PA and MMA in mitochondrial and other monogenic diseases, using data provided by the Human Phenotype Ontology. Lastly, we combined this with evidence from literature to draw conclusions on the possible role of mitochondrial impairment in each complication. Altogether, this review provides a comprehensive overview on what we, to date, do and do not understand about pathophysiology of complications occurring in PA and MMA and about the role of mitochondrial impairment herein.

Zinc and skin: an update

The essential trace element zinc (Zn) plays a key role in the development, differentiation and growth of various human tissues. Zinc homeostasis is primarily regulated by two zinc transporter families (solute-linked carrier families, SLC). Disturbances in zinc metabolism may give rise to disorders that typically manifest themselves on the skin. An autosomal recessive zinc deficiency disorder, acrodermatitis enteropathica is caused by a mutation in the gene coding for the ZIP4 transporter. Due to intestinal malabsorption, affected infants develop clinical signs and symptoms shortly after weaning. Acquired zinc deficiency is a rare but underdiagnosed disorder associated with various etiologies and variable clinical manifestations. Depending on the patient's age, a multitude of causes have to be considered. Given the characteristic periorificial and acral lesions, the clinical diagnosis is usually made by dermatologists. Laboratory confirmation includes measurement of plasma zinc levels and - as a supplementary measure - zinc-dependent enzymes such as alkaline phosphatase. Oral zinc replacement therapy frequently leads to clinical remission within a few days. Depending on the cause, disease management should include cooperation with pediatricians and gastroenterologists in order to guarantee optimal patient care.

Acrodermatitis dysmetabolica as a sign of methylmalonic aciduria decompensation

Methylmalonic aciduria children must follow an adequate diet with low protein intake and should be regularly monitored to prevent complications. Although skin lesions like acrodermatitis enteropathica are rare in this disease, their appearance should be correlated with possible low plasma isoleucine level and it can be a sign of decompensation.

Skin Lesions Associated with Nutritional Management of Maple Syrup Urine Disease

Introduction

Maple syrup urine disease (MSUD) is an inborn error of branched chain amino acids (BCAAs) metabolism. We report an infant with MSUD who developed 2 episodes of cutaneous lesions as a result of isoleucine deficiency and zinc deficiency, respectively.

Case Presentation

A 12-day-old male infant was presented with poor milk intake and lethargy. The diagnosis of MSUD was made based on clinical and biochemical data.

Management and Outcome

Specific dietary restriction of BCAAs was given. Subsequently, natural protein was stopped as the patient developed hospital-acquired infections which resulted in an elevation of BCAAs. Acrodermatitis dysmetabolica developed and was confirmed to be from isoleucine deficiency. At the age of 6 months, the patient developed severe lethargy and was on natural protein exclusion for an extended period. Despite enteral supplementation of zinc sulfate, cutaneous manifestations due to zinc deficiency occurred.

Discussion

Skin lesions in MSUD patients could arise from multiple causes. Nutritional deficiency including isoleucine and zinc deficiencies can occur and could complicate the treatment course as a result of malabsorption, even while on enteral supplementation. Parenteral nutrition should be considered and initiated accordingly. Clinical status, as well as BCAA levels, should be closely monitored in MSUD patients.

Dietary practices in propionic acidemia: A European survey

Background

The definitive dietary management of propionic acidaemia (PA) is unknown although natural protein restriction with adequate energy provision is of key importance.

Aim

To describe European dietary practices in the management of patients with PA prior to the publication of the European PA guidelines.

Methods

This was a cross-sectional survey consisting of 27 questions about the dietary practices in PA patients circulated to European IMD dietitians and health professionals in 2014.

Results

Information on protein restricted diets of 186 PA patients from 47 centres, representing 14 European countries was collected. Total protein intake [PA precursor-free L-amino acid supplements (PFAA) and natural protein] met WHO/FAO/UNU (2007) safe protein requirements for age in 36 centres (77%). PFAA were used to supplement natural protein intake in 81% (n = 38) of centres, providing a median of 44% (14–83%) of total protein requirement. Seventy-four per cent of patients were prescribed natural protein intakes below WHO/FAO/UNU (2007) safe levels in one or more of the following age groups: 0–6 m, 7–12 m, 1–10 y, 11–16 y and > 16 y. Sixty-three per cent (n = 117) of patients were tube fed (74% gastrostomy), but only 22% received nocturnal feeds.

Conclusions

There was high use of PFAA with intakes of natural protein commonly below WHO/FAO/UNU (2007) safe levels. Optimal dietary management can only be determined by longitudinal, multi-centre, prospective case controlled studies. The metabolic instability of PA and small patient cohorts in each centre ensure that this is a challenging undertaking.

Isoleucine Deficiency in a Neonate Treated for Maple Syrup Urine Disease Masquerading as Acrodermatitis Enteropathica

BACKGROUND

Special diet with restricted branched-chain-amino-acids used for treating maple syrup urine disease can lead to specific amino acid deficiencies.

CASE CHARACTERISTICS

We report a neonate who developed skin lesions due to isoleucine deficiency while using specialised formula.

INTERVENTION/OUTCOME

Feeds were supplemented with expressed breast milk. This caused biochemical and clinical improvement with resolution of skin lesions.

MESSAGE

Breast milk is a valuable and necessary adjunct to specialized formula in maple syrup urine disease to prevent specific amino acid deficiency in the neonatal period.

Methylmalonic and propionic acidemias: clinical management update

PURPOSE OF REVIEW

Recent clinical studies and management guidelines for the treatment of the organic acidopathies methylmalonic acidemia (MMA) and propionic acidemia address the scope of interventions to maximize health and quality of life. Unfortunately, these disorders continue to cause significant morbidity and mortality due to acute and chronic systemic and end-organ injury.

RECENT FINDINGS

Dietary management with medical foods has been a mainstay of therapy for decades, yet well controlled patients can manifest growth, development, cardiac, ophthalmological, renal, and neurological complications. Patients with organic acidopathies suffer metabolic brain injury that targets specific regions of the basal ganglia in a distinctive pattern, and these injuries may occur even with optimal management during metabolic stress. Liver transplantation has improved quality of life and metabolic stability, yet transplantation in this population does not entirely prevent brain injury or the development of optic neuropathy and cardiac disease.

SUMMARY

Management guidelines should identify necessary screening for patients with methylmalonic acidemia and propionic acidemia, and improve anticipatory management of progressive end-organ disease. Liver transplantation improves overall metabolic control, but injury to nonregenerative tissues may not be mitigated. Continued use of medical foods in these patients requires prospective studies to demonstrate evidence of benefit in a controlled manner.

Maple Syrup Urine Disease Complicated with Kyphoscoliosis and Myelopathy

Maple syrup urine disease (MSUD) is an autosomal recessive aminoacidopathy secondary to an enzyme defect in the catabolic pathway of the branched-chain amino acids (BCAAs: leucine, isoleucine, and valine). Accumulation of their corresponding keto-acids leads to encephalopathy if not treated in time. A newborn male patient was suspected to have MSUD after tandem mass study when he presented symptoms and signs suggestive neonatal sepsis, anemia, and diarrhea. Food restriction of BCAAs was started; however, acrodermatitis enteropathica-like skin eruptions occurred at age 2 months. The skin rashes resolved after adding BCAAs and adjusting the infant formula. At age 7 months, he suffered from recurrent skin lesions, zinc deficiency, osteoporosis, and kyphosis of the thoracic spine with acute angulation over the T11-T12 level associated with spinal compression and myelopathy. After supplementation of zinc products and pamidronate, skin lesions and osteopenia improved gradually. Direct sequencing of the DBT gene showed a compound heterozygous mutation [4.7 kb deletion and c.650-651insT (L217F or L217fsX223)]. It is unusual that neurodegeneration still developed in this patient despite diet restriction. Additionally, brain and spinal magnetic resonance imaging, bone mineral density study, and monitoring of zinc status are suggested in MSUD patients.

The Nutritional Intake of Patients with Organic Acidaemias on Enteral Tube Feeding: Can We Do Better?

BACKGROUND

Detailed nutritional intake data on children with organic acidaemias (OA) (propionic acidaemia (PA), vitamin B12 nonresponsive methylmalonic acidaemia (MMA) and isovaleric acidaemia (IVA)) remains unreported. Aim and subjects: A review of the longitudinal nutritional intake of 14 children with organic acidaemias (PA n = 8; MMA n = 5; IVA n = 1) dependent on enteral tube feeding (≥90% of energy requirements) from a single treatment centre.

METHODS

Nutritional intake (energy, protein, precursor-free L-amino acids, vitamins and minerals), anthropometry and nutritional biochemistry data were collated from diagnosis to current age.

RESULTS

The median energy intake was only 72% (63-137) of the estimated average DH (1991) requirement (EAR), decreasing significantly by 40% between 6 months and 5 years (p < 0.05). Total protein intake met WHO/FAO/UNU (2007) safe intake levels with median (range) precursor-free L-amino acids providing 21% (14-28) of total protein intake. Median mineral intake for sodium was 57% (20-97%), potassium 64% (27-125%) and magnesium 72% (22-116%) and was consistently < RNI for all age points. Fibre median intake was 4 g/day (0-11 g), and fluid intake provided 80% (60-100%) of the requirements for age. Linear growth was poor, and children were overweight for their height (1-10 years: z score median weight +0.6, height -1.2). Nutritional markers consistently indicated that plasma valine concentrations were < target reference ranges in PA and MMA. Iron deficiency anaemia was common in MMA/PA, and in PA, 50% of plasma zinc concentrations were < reference range.

CONCLUSION

In MMA/PA, energy intake decreases over time, weight gain accelerates, but linear height is poor. There are many nutrient deficiencies which may affect short- and long-term outcome of patients with organic acidaemias. The quality of long-term diet in these conditions deserves more attention.

Proposed guidelines for the diagnosis and management of methylmalonic and propionic acidemia

Methylmalonic and propionic acidemia (MMA/PA) are inborn errors of metabolism characterized by accumulation of propionic acid and/or methylmalonic acid due to deficiency of methylmalonyl-CoA mutase (MUT) or propionyl-CoA carboxylase (PCC). MMA has an estimated incidence of ~ 1: 50,000 and PA of ~ 1:100’000 -150,000. Patients present either shortly after birth with acute deterioration, metabolic acidosis and hyperammonemia or later at any age with a more heterogeneous clinical picture, leading to early death or to severe neurological handicap in many survivors. Mental outcome tends to be worse in PA and late complications include chronic kidney disease almost exclusively in MMA and cardiomyopathy mainly in PA. Except for vitamin B₁₂ responsive forms of MMA the outcome remains poor despite the existence of apparently effective therapy with a low protein diet and carnitine. This may be related to under recognition and delayed diagnosis due to nonspecific clinical presentation and insufficient awareness of health care professionals because of disease rarity.

These guidelines aim to provide a trans-European consensus to guide practitioners, set standards of care and to help to raise awareness. To achieve these goals, the guidelines were developed using the SIGN methodology by having professionals on MMA/PA across twelve European countries and the U.S. gather all the existing evidence, score it according to the SIGN evidence level system and make a series of conclusive statements supported by an associated level of evidence. Although the degree of evidence rarely exceeds level C (evidence from non-analytical studies like case reports and series), the guideline should provide a firm and critical basis to guide practice on both acute and chronic presentations, and to address diagnosis, management, monitoring, outcomes, and psychosocial and ethical issues. Furthermore, these guidelines highlight gaps in knowledge that must be filled by future research. We consider that these guidelines will help to harmonize practice, set common standards and spread good practices, with a positive impact on the outcomes of MMA/PA patients.

Single amino acid supplementation in aminoacidopathies: a systematic review

Aminoacidopathies are a group of rare and diverse disorders, caused by the deficiency of an enzyme or transporter involved in amino acid metabolism. For most aminoacidopathies, dietary management is the mainstay of treatment. Such treatment includes severe natural protein restriction, combined with protein substitution with all amino acids except the amino acids prior to the metabolic block and enriched with the amino acid that has become essential by the enzymatic defect. For some aminoacidopathies, supplementation of one or two amino acids, that have not become essential by the enzymatic defect, has been suggested. This so-called single amino acid supplementation can serve different treatment objectives, but evidence is limited. The aim of the present article is to provide a systematic review on the reasons for applications of single amino acid supplementation in aminoacidopathies treated with natural protein restriction and synthetic amino acid mixtures.

Acrodermatitis enteropathica-like skin lesions in a neonate

A male neonate was born to a sixth-gravida mother with a history of four early-neonatal deaths. On day 21 of life, the patient was admitted for poor feeding, vomiting and encephalopathy. Final diagnosis of propionic acidaemica (propionylcarnitine, 17.67 μmol/L) was made. He was managed by peritoneal dialysis followed by protein-free and special lipid diet, sodium benzoate and multivitamins. On day 28 of life, he developed acrodermatitis enteropathica-like skin lesions on perioral and diaper area that did not respond to oral zinc or antimicrobials. A possibility of acrodermatitis acidaemica was kept and supplementation with essential amino acids started, following which the skin lesions regressed.

Amino acid metabolism in patients with propionic acidaemia

Propionic acidaemia (PA) is an inborn error of intermediary metabolism caused by deficiency of propionyl-CoA carboxylase. The metabolic block leads to a profound failure of central metabolic pathways, including the urea and the citric acid cycles. This review will focus on changes in amino acid metabolism in this inborn disorder of metabolism. The first noted disturbance of amino acid metabolism was hyperglycinaemia, which is detectable in nearly all PA patients. Additionally, hyperlysinaemia is a common observation. In contrast, concentrations of branched chain amino acids, especially of isoleucine, are frequently reported as decreased. These non-proportional changes of branched-chain amino acids (BCAAs) compared with aromatic amino acids are also reflected by the Fischer's ratio (concentration ratio of BCAAs to aromatic amino acids), which is decreased in PA patients. As restricted dietary intake of valine and isoleucine as precursors of propionyl-CoA is part of the standard treatment in PA, decreased plasma concentrations of BCAAs may be a side effect of treatment. The concentration changes of the nitrogen scavenger glutamine have to be interpreted in the light of ammonia levels. In contrast to other hyperammonaemic syndromes, in PA plasma glutamine concentrations do not increase in hyperammonaemia, whereas CSF glutamine concentrations are elevated. Despite lactic acidaemia in PA patients, hyperalaninaemia is only rarely reported. The mechanisms underlying the observed changes in amino acid metabolism have not yet been elucidated, but most of the changes can be at least partly interpreted as consequence of disturbance of anaplerosis.

Natural history of propionic acidemia

Propionic acidemia is an organic acidemia that can lead to metabolic acidosis, coma and death, if not treated appropriately in the acute setting. Recent advancements in treatment have allowed patients with propionic acidemia to live beyond the neonatal period and acute presentation. The natural history of the disease is just beginning to be elucidated as individuals reach older ages. Recent studies have identified the genomic mutations in the genes PCCA and PCCB. However, as of yet no clear genotype-phenotype correlations are known. As patients age, the natural progression of propionic acidemia illuminates intellectual difficulties, increased risk for neurological complications, including stroke-like episodes, cardiac complications, and gastrointestinal difficulties, as well as a number of other complications. This article reviews the available literature for the natural history of propionic acidemia.

Acrodermatitis enteropathica-like eruption in metabolic disorders: acrodermatitis dysmetabolica is proposed as a better term

BACKGROUND

Acrodermatitis acidemica is a recently proposed term for the rash that is similar to acrodermatitis enteropathica, which is encountered in organic acidemias. However, acrodermatitis enteropathica-like eruption may be seen in metabolic disorders other than organic acidemias.

OBJECTIVE

The aim of this study was to evaluate the clinical features of acrodermatitis enteropathica-like eruption secondary to metabolic disorders.

METHODS

Clinical and demographic features of 12 patients with acrodermatitis enteropathica-like eruption were prospectively evaluated between 2004 and 2006 in this single-center study.

RESULTS

Among the 12 patients, underlying metabolic disorders included maple syrup urine disease (n = 5), methylmalonic acidemia (n = 3), phenylketonuria (n = 2), ornithine transcarbamylase deficiency (n = 1), and propionic acidemia (n = 1). Mean age at first presentation was 29.9 months. Mean duration of acrodermatitis enteropathica-like eruption at the time of presentation was 25.2 days. The diaper area was involved in all presentations. Plasma zinc level was measured in 62.5% (n = 10) of the presentations and all had normal levels. All phenylketonuria cases had a low plasma phenylalanine level, and a low plasma isoleucine level was observed in the propionic acidemia case and all maple syrup urine disease cases. The rash responded dramatically to appropriate diet management in all cases.

CONCLUSION

In this study, acrodermatitis enteropathica-like eruption was noted in various metabolic disorders, including organic acidemias. We suggest that acrodermatitis dysmetabolica might be a better term for acrodermatitis enteropathica-like eruption occurring secondary to metabolic disorders other than acquired zinc deficiency.

Acrodermatitis enteropathica–like eruption and failure to thrive as presenting signs of cystic fibrosis

We describe a female infant with an acrodermatitis enteropathica-like eruption as the presenting sign of rapidly fatal cystic fibrosis. The patient had growth retardation, developed an erythematous eruption unresponsive to oral zinc, and finally a generalized erosive dermatitis with associated edema, anemia and hypoproteinemia.

Propionic acidemia manifesting with low isoleucine generalized exfoliative dermatosis

We describe an infant with propionic acidemia who developed a generalized exfoliative eruption. Preceding the eruption, he was on an amino acid restricted formula. Within days of liberalizing his restricted diet, the eruption resolved completely. A similar dermatitis has been reported in infants with inborn errors of metabolism who were on amino acid modified formulas. However, in most instances, the eruption was predominantly limited to the periorificial regions. Most critical in the etiology of cutaneous eruptions in these patients is low serum isoleucine. Amino acid malnutrition should be considered in the differential diagnosis of generalized exfoliative dermatosis in an infant. Supplementation with isoleucine-containing dietary proteins results in rapid clinical resolution.

Acrodermatitis enteropathica-like dermatosis associated with ornithine transcarbamylase deficiency

The urea cycle is the major metabolic pathway for excretion of waste nitrogen. Ornithine transcarbamylase deficiency is the most frequent urea cycle disorder. It is a hereditary-X-linked disease with over 150 mutations described. Ornithine transcarbamylase deficiency causes vomiting, lethargy, hyperventilation, and even death, mainly in the neonatal period. Ammonia, an extremely toxic molecule for the organism, is generated during protein catabolism and is accumulated in patients with this deficiency. Part of the treatment consists of a low-protein diet, to avoid hyperammonemia episodes, which can even have a fatal outcome. Patients can become deficient in several amino acids, either through the low-protein diet or directly through the primary enzyme deficiency; this in turn can cause an acrodermatitis enteropathica-like dermatosis.

Lesões de pele do tipo acrodermatite enteropática em duas crianças com doença da urina de xarope do bordo

Lesões cutâneas semelhantes à acrodermatite enteropática têm sido descritas em pacientes com algumas doenças metabólicas tratadas com dietas hipoprotéicas. Esses pacientes geralmente apresentam baixos níveis séricos de alguns aminoácidos, especialmente da isoleucina. Descrevemos dois pacientes que evoluíram com lesões semelhantes às da acrodermatite enteropática durante o tratamento da doença da urina do xarope de bordo , sem deficiência do zinco. A suplementação da isoleucina determinou rápida melhora das lesões dermatológicas.

Acrodermatitis enteropathica-like eruptions in a child with Hartnup disease

Acrodermatitis enteropathica-like eruptions, not related to zinc deficiency, have been rarely reported in some metabolic disorders. Reported patients usually had low levels of essential amino acids, particularly isoleucine. Here we report a girl who first presented with an acrodermatitis enteropathica-like eruption and eventually had the diagnosis of Hartnup disease with a normal isoleucine level. We discuss the probable cause of her skin lesions and the differential diagnosis with pellagra.

Pseudo-acrodermatite entéropathique secondaire à un déficit en acides aminés ramifiés au cours du traitement d’une leucinose

INTRODUCTION

Clinical pictures resembling acrodermatitis enteropathica have been described in acquired zinc deficiency and deficiencies of other nutrients such as biotin, essential fatty acids and amino acids as well as biotin metabolism disorders. We describe the case of an infant with maple syrup urine disease who developed an acrodermatitis-like syndrome due to iatrogenic valine and isoleucine deficiency.

CASE-REPORT

A diagnosis of maple syrup urine disease was made in a 5-month-old infant girl with severe neurologic disorders with extremely high levels of the three branched-chain amino acids (leucine, valine and isoleucine) in plasma and urine. Seven days after the start of therapy with a diet excluding these branched-chain amino acids, plasma isoleucine and valine concentrations were low while plasma leucine remained elevated. At the same time, a periorificial and acral dermatitis appeared together with diarrhea. Serum zinc concentrations were normal. A diagnosis of acrodermatitis enteropathica-like syndrome secondary to isoleucine and valine deficiency was suspected. Valine and isoleucine supplementation resulted in rapid resolution of the eruption.

DISCUSSION

Several cases of acrodermatitis enteropathica-like eruptions resulting from therapeutic protein restriction diets have been described in infants with different aminoacidopathies. The accompanying dermatosis was associated with a raised plasma leucine/isoleucine ratio and/or isoleucine deficiency, or valine deficiency. While the exact pathogenesis of the skin lesions has not been established, these observations show that branched-chain amino acids are essential for normal growth and differentiation of keratinocytes. The essential role of isoleucine is further substantiated by the fact that its presence is critical in keratinocyte culture media, with growth arrest occurring upon its depletion.

Nutrition therapy of organic acidaemias with amino acid-based formulas: emphasis on methylmalonic and propionic acidaemia

Failure to thrive has been described in patients with organic acidaemias due to a variety of causes, both organic and inorganic. Failure to thrive in patients with methylmalonic acidaemia (MMA) and propionic acidaemia (PA) may be related to inadequate protein and energy intake rather than pathology of disease. Inadequate protein intake can also result in decreased resting energy expenditure, clinical signs and symptoms of amino acid deficiency, increased risk of infection, and developmental delay. Amino acid-based formulas (also referred to as 'medical foods') provide a key source of nitrogen, energy, vitamins and minerals which, when prescribed appropriately, can promote anabolism and growth. Although protein requirements in patients with organic acidaemias have not been elucidated, providing an adequate balance of protein, energy and other nutrients will help promote growth.

Pseudo-acrodermatite entéropathique par carence alimentaire en isoleucine chez un nourrisson atteint de leucinose

INTRODUCTION

Leucinosis (maple syrup urine disease) is a metabolic disorder caused by an enzymatic deficiency involved in the degradative pathways of the three branched-chain amino acids. We report an observation of acrodermatitis enteropathica-like syndrome induced by essential amino acid deficiency in a child with leucinosis.

CASE REPORT

A child with leucinosis was referred to our hospital for exfoliative dermatitis of the perioral and anogenital regions associated with diarrhea and pancytopenia. The diagnosis of iatrogenic acrodermatitis enteropathica-like syndrome was confirmed after screening showing isoleucine deficiency. Rapid response was observed after adequate isoleucine supplementation.

DISCUSSION

The acrodermatitis enteropathica-like eruption in our patient was due to an iatrogenic amino acid nutritional imbalance. Our observation underlines the risk of using a branched-chain amino acid-free formula without adequate supplementation of deficient amino acids. In addition, dietary insufficiency of isoleucine, associated with the treatment of organic aciduria should be added to the causes of acrodermatitis enteropathica-like syndrome.

Improved growth and nutrition status in children with methylmalonic or propionic acidemia fed an elemental medical food

BACKGROUND

Failure-to-thrive (FTT) has been described in patients with organic acidemias treated with low protein diets.

OBJECTIVE

To determine if patients with methylmalonic (MMA) or propionic acidemia (PA) can achieve normal growth and nutrition status.

METHODS

A 6-month multicenter outpatient study was conducted with infants and toddlers treated with Propimex-1 Amino Acid-Modified Medical Food With Iron (Ross Products Division, Abbott Laboratories, Columbus, OH). Main outcome measures were anthropometrics, protein status indices, plasma retinol, and alpha-tocopherol.

RESULTS

Sixteen patients completed the study. Mean baseline age was 0.54 +/- 0.02 years (range 0.03-3.00 years). By study end, mean National Center for Health Statistics (NCHS) weight centile increased from 26 to 49%; mean crown-heel length centile from 25 to 33%; and mean head circumference centile from 43 to 54%. Mean (+/- SE) protein and energy intakes by <6-month-old, 6<12-month-old, and 1<4-year-old patients were 15.3 +/- 0.9 g and 645 +/- 10 kcal; 18.3 +/- 1.1 g and 741 +/- 92 kcal; and 25.1 +/- 2.46 g and 1062 +/- 100 kcal, respectively. Plasma glycine concentrations were significantly and negatively correlated with energy intake (r=-0.77, p<0.0005). No correlation was found between dietary protein intakes and plasma ammonia concentrations. Protein status indices, retinol and alpha-tocopherol concentrations were within reference ranges at study end.

CONCLUSIONS

Propimex-1 improved growth and nutrition status in patients with MMA or PA in just 6 months when fed in sufficient amounts. Providing energy and protein for patients with FTT at intakes recommended for catch-up growth may have resulted in even better growth.

Branched-chain organic acidurias

Branched chain organic acidurias are a group of disorders that result from an abnormality of specific enzymes involving the catabolism of branched chain amino acids (leucine, isoleucine, valine). Maple syrup urine disease (MSUD), isovaleric acidaemia (IVA), propionic aciduria (PA) and methylmalonic aciduria (MMA) represent the most commonly encountered abnormal organic acidurias. All these four disorders present in neonates as a neurologic distress of the intoxication type with either ketosis or ketoacidosis and hyperammonaemia. There is a free interval between birth and clinical symptoms. MMA, PA and IVA present with a severe dehydration, leuconeutropenia and thrombopenia which can mimic sepsis. All these disorders can be diagnosed by identifying acylcarnitine and other organic acid compounds in plasma and urine by gas chromatography mass spectrometry or tandem MS-MS. These disorders are amenable to treatment by removing toxic compounds and by using special diets and carnitine.

Acrodermatitis enteropathica-like eruption in an infant with nonketotic hyperglycinemia

Acrodermatitis enteropathica is a rare inherited disorder characterized by zinc deficiency and a triad of dermatitis, diarrhea, and alopecia. It is an autosomal recessive condition thought to be due to the inability to absorb zinc from the gastrointestinal tract. Acquired zinc deficiency due to a variety of etiologies may produce a similar clinical picture. These causes include inadequate supply, malabsorption, and low zinc stores. In addition to zinc, deficiencies of other nutrients such as branched chain amino acids have induced an acrodermatitis enteropathica-like eruption. We describe a case of a 26-month-old boy with a rare inborn error of metabolism known as nonketotic hyperglycinemia who developed an acrodermatitis enteropathica-like eruption. In addition to zinc deficiency, the patient was deficient in branched chain amino acids due to a low protein diet instituted to reduce his elevated glycine levels. The rash did not respond to zinc replacement alone, and therefore is most likely a combination of amino acid and zinc deficiency. Acrodermatitis enteropathica-like eruptions have been described in other conditions that cause decreased serum amino acids, such as maple syrup urine disease and organic acidurias. This is the first case describing an association between acrodermatitis enteropathica and nonketotic hyperglycinemia.

Malnutrition-associated rash of cystic fibrosis

Rash is a rare presenting sign of cystic fibrosis (CF) complicated by protein-calorie malnutrition. We measured essential fatty acid (EFA) levels in the serum of a 4-month-old girl with an erythematous, desquamating, periorificially accentuated rash in association with malnutrition and her 2-year-old sister who was diagnosed concurrently with CF but had no rash or signs of malnutrition. Both patients had biochemical evidence of EFA deficiency, suggesting that development of the rash is multifactorial. Clinical presentation, management, and possible modes of pathogenesis of the rash are reviewed. Pathogenesis of the rash appears to involve a complex interaction among deficiencies of EFAs, zinc, protein, and possibly copper, leading to disordered prostaglandin metabolism or cytokine production, or free radical-induced damage to cellular membranes due to a lack of nutrient-derived protective antioxidants.

Iatrogenic isolated isoleucine deficiency as the cause of an acrodermatitis enteropathica-like syndrome

We present two patients with a suspected inborn error of metabolism. A female newborn presented with dysmorphic features and convulsions. Metabolic screening suggested a defect in isoleucine degradation. Within 2 weeks after the introduction of an isoleucine-restricted diet, she developed a severe acrodermatitis enteropathica-like syndrome. The plasma level of isoleucine was low with a normal leucine/isoleucine ratio. The second patient, a female infant deficient in leucine as a result of a leucine-restricted diet, did not develop a dermatosis. Isoleucine is essential for normal growth and differentiation of keratinocytes and enterocytes. Deficiency of isoleucine, and not leucine or an imbalance in the leucine/isoleucine ratio, may result in an acrodermatitis enteropathica-like syndrome.

The management and outcome of propionic and methylmalonic acidaemia

The management of the severe variants of methylmalonic and propionic acidaemia remains difficult. With conventional therapy of diet, carnitine and antibiotics, mortality is high and long-term complications are common. Liver transplantation appears to be an important alternative.