Sudden unexpected infant death (SUDI) in a newborn due to medium chain acyl CoA dehydrogenase (MCAD) deficiency with an unusual severe genotype

An 8-year-old child during the first year of life manifested severe atopic dermatitis and chronic diarrhea with mucorrhea and rectal bleeding; a fish-free diet was started based on weakly positive skin-prick tests to codfish extract. At the age of 4?years the child began to suffer of recurrent pancreatitis. When he came to our attention for the evaluation of his fish allergy, he was asymptomatic; a weak reactivity to codfish was observed (SPTs: cod, 4?mm, sIgE ImmunoCAP: cod, 1.30kU/l). The food challenge test with cod was negative. When the child ate cod again, within 5 minutes, developed anaphylactic reaction and complained of abdominal pain compatible with pancreatitis (enzyme serum levels risen and parenchymal oedema at ultrasonography), that resolved within 7?days after specific therapy. This case raises two issues: the elimination diet in asymptomatic food allergy on the basis only of SPT and the ethicality of food challenge in gastrointestinal chronic disease.     

Shellfish allergy in children

Food allergies affect approximately 3.5–4.0% of the world's population and can range from a mere inconvenience to a life-threatening condition. Over 90% of food allergies in childhood are caused by eight foods: cow's milk, hen's egg, soy, peanuts, tree nuts, wheat, fish, and shellfish. Shellfish allergy is known to be common and persistent in adults, and is an important cause of food induced anaphylaxis around the world for both children and adults. Most shellfish-allergic children have sensitivity to dust mite and cockroach allergens. Diagnostic cut-off levels for skin prick testing in children with shrimp allergy exist but there are no diagnostic serum-specific immunoglobulin E (IgE) values. All patients with symptoms of IgE-mediated reactions to shellfish should receive epinephrine autoinjectors, even if the initial symptoms are mild. In this study, we review three cases of clinical presentations of shellfish allergy in children.     

Quels sont les examens complémentaires à réaliser en allergologie pédiatrique ?

The diagnostic of respiratory allergy is done by the concordance of clinical history and the positivity of the skin prick testing. Blood sample is not essential but must be done before specific immunotherapy. In IgE food allergy, positivity of skin prick testing and specific IgE allows to make the diagnostic of allergic sensitisation. The diagnostic of food allergy is done by the positivity of the oral food challenge. In mixed IgE and cell-mediated food allergy, it is necessary to do skin prick testing and atopy patch testing with the food usually ingested by the child. If these tests are positive, they are pertinent when the food eviction improves the clinical symptoms. The release of the symptoms during the oral food challenge will confirm the diagnostic of food allergy.     

Anaphylactic reaction to goat's milk in a cow's milk-allergic infant

Goat's milk has been used as a substitute for cow's milk in cow's milk-allergic individuals. It is currently advocated for this purpose in writings and internet resources directed at the lay person, and infant formula based on goat's milk is available in many countries. Clinically significant cross-allergenicity between cow's and goat's milk has been noted, but a life-threatening cross-reaction has not been reported. We describe a 4-month-old infant with immunologically documented cow's milk protein allergy but no prior exposure to goat's milk who developed anaphylaxis after the ingestion of commercial goat's milk. Subsequent skin prick testing demonstrated a specific reaction to goat's milk. Thus, the cross-allergenicity between cow's and goat's milk proteins can lead to life-threatening complications. Individuals allergic to cow's milk protein should avoid goat's milk and goat's milk products.     

Anaphylaxis during skin testing with food allergens in children

Skin testing is the diagnostic cornerstone for allergies and is considered extremely safe. It is usually performed with the prick and the prick-to-prick method. The aim of this study is to report the first two pediatric cases of systemic allergic reactions during skin prick tests (SPT) with commercial food allergens. Both patients had a history of fish allergy. A 5-year-old girl, with a history of atopic dermatitis and asthma, reported an episode of urticaria and angioedema due to ingestion of fish, which had occurred 2 years before consultation. Ten minutes after having completed SPT to fish extracts, which had resulted positive, she suffered from generalized pruritus, nausea, stomach pain, and loss of consciousness. A 9-year-old boy, with a history of asthma and two episodes of acute urticaria and angioedema upon eating fish during infancy, reported a recent episode of oropharyngeal pruritus after tasting salmon. He was evaluated for fish allergy with SPT but developed conjunctivitis and acute urticaria during the first 10 min of the test. Anaphylaxis appears to be a rare side effect of skin testing in pediatric patients. Children with a history of asthma and atopic dermatitis are more likely to react.     

Egg allergy

Egg allergy is one of the most common food allergies in infants and young children. The great majority is not life-threatening and management involves exclusion of egg from the diet and regular review with the expectation that the majority of children will outgrow the allergy by school age. Judgment is required as to when the dietary elimination of egg is no longer required. This decision may be helped by demonstrating loss of sensitivity by skin prick or specific IgE testing and in some cases a supervised food challenge. Particular issues in management arise with more severe, potentially life-threatening reactions, with immunization with vaccines prepared in eggs, with the diagnosis of egg hypersensitivity as a cause of delayed exacerbations of eczema which can be non-IgE mediated, and in deciding whether a child can be allowed to ingest small amounts of cooked egg through egg-containing foods while continuing to avoid raw egg or larger amounts of whole egg. Cases which illustrate these issues are presented.     

Fish allergy in childhood

Fish and its derived products play an important role in human nutrition, but they may also be a potent food allergen. Fish can be an ingested, contact, and inhalant allergen. Gad c I, a Parvalbumin, the major allergen in codfish, is considered as fish and amphibian pan‐allergen. Prevalence of fish allergy appears to depend on the amount of fish eaten in the local diet. In Europe, the highest consumption occurs in Scandinavian countries, Spain and Portugal. In Spain, fish is the third most frequent allergen in children under 2 yr of age after egg and cow’s milk. An adverse reaction to fish may be of non‐allergic origin, due to food contamination or newly formed toxic products, but the most frequent type of adverse reactions to fish are immunologic‐mediated reactions (allergic reactions). Such allergic reactions may be both IgE‐mediated and non‐IgE‐mediated. Most cases are IgE‐mediated, due to ingestion or contact with fish or as a result of inhalation of cooking vapors. Some children develop non‐IgE‐mediated type allergies such as food protein induced enterocolitis syndrome. The clinical symptoms related to IgE‐mediated fish allergy are most frequently acute urticaria and angioedema as well as mild oral symptoms, worsening of atopic dermatitis, respiratory symptoms such as rhinitis or asthma, and gastrointestinal symptoms such as nausea and vomiting. Anaphylaxis may also occur. Among all the species studied, those from the Tunidae and Xiphiidae families appear to be the least allergenic.     

Allergy skin testing after topical anesthesia

Immediate skin test reactions are the hallmark of atopic diseases. EMLA (eutectic mixture of local anesthetics) is a local anesthetic that reduces the pain and apprehension for skin testing. We studied EMLA effects on the skin prick test with allergen and histamine. Reactions were evaluated by means of wheal and flare crossed diameters, speed of reaction and local temperature changes. One hour occlusion dressing with EMLA significantly delayed the beginning of reaction with antigen (129%) and histamine (101%). It decreased wheal diameter (33% and 15%) as well as local temperature variation (55% and 80%) respectively with antigen and histamine. Local anesthesia with EMLA probably interferes with histamine action and reduces the immediate skin test reaction. Therefore, it should not be used to reduce the pain of allergy skin testing.     

Diagnosis of food allergy in children: toward a standardization of food challenge

Adverse reactions to food represent a common complaint in childhood; however, only a small proportion of children have proven clinically relevant food allergy. The foods most commonly involved in food allergy are cow's milk, hen's eggs, peanuts, tree nuts, seeds, soy, wheat, fish, and crustaceans. The diagnostic workup of suspected food allergy includes the patient's history, skin prick testing, the measurement of food-specific immunoglobulin E antibodies, and, more recently, the atopy patch test. Because none of these parameters can accurately predict tolerance, the gold standard for diagnosing food allergy is still the double-blind, placebo-controlled food challenge. Although numerous efforts have been made to standardize the procedure, there is a need for improvement. This review presents the current status of the indication and performance of controlled oral food challenges in children with suspected food-related symptoms. It covers aspects of indications and contraindications, blinding, diet before the challenge, the practical performance, the handling of medication, the interpretation of test results, suitable locations for testing, safety considerations, and the procedure after a period of avoidance. Efforts to standardize oral food challenges to achieve the best possible decision on a diet are important to avoid an unnecessary diet that may be harmful to the child.     

Parvalbumin--the major tropical fish allergen.

Fish allergy is common in countries where consumption is high. Asian nations are amongst the world's largest consumers of fish but the allergen profiles of tropical fish are unknown. This study sought to evaluate the allergenicity of four commonly consumed tropical fish, the threadfin (Polynemus indicus), Indian anchovy (Stolephorus indicus), pomfret (Pampus chinensis) and tengirri (Scomberomorus guttatus). Immunoglobulin E (IgE) cross-reactivity with parvalbumin of cod fish (Gad c 1), the major fish allergen, was also studied. Detection of tropical fish and cod specific-IgE was performed by UniCap assay, and skin prick tests were also carried out. The IgE-binding components of tropical fish were identified using IgE immunoblot techniques, and cross-reactivity with Gad c 1 was assessed by ELISA inhibition and IgE immunoblot inhibition. Clinically, nine of 10 patients studied were allergic to multiple fish. All patients exhibited detectable specific-IgE to cod fish (10 of 10 skin prick test positive, eight of 10 UniCap assay positive) despite lack of previous exposure. The major allergen of the four tropical fish was the 12-kDa parvalbumin. IgE cross-reactivity of these allergens to Gad c 1 was observed to be moderate to high in the tropical fish studied. Parvalbumins are the major allergens in commonly consumed tropical fish. They are cross-reactive with each other as well as with Gad c 1. Commercial tests for cod fish appear to be sufficient for the detection of tropical fish specific-IgE.     

Fish and shellfish allergy in children: Review of a persistent food allergy

The increased consumption of fish and shellfish has resulted in more frequent reports of adverse reactions to seafood, emphasizing the need for more specific diagnosis and treatment of this condition and exploring reasons for the persistence of this allergy. This review discusses interesting and new findings in the area of fish and shellfish allergy. New allergens and important potential cross‐reacting allergens have been identified within the fish family and between shellfish, arachnids, and insects. The diagnostic approach may require prick to‐prick tests using crude extracts of both raw and cooked forms of seafood for screening seafood sensitization before a food challenge or where food challenge is not feasible. Allergen‐specific immunotherapy can be important; mutated less allergenic seafood proteins have been developed for this purpose. The persistence of allergy because of seafood proteins’ resistance after rigorous treatment like cooking and extreme pH is well documented. Additionally, IgE antibodies from individuals with persistent allergy may be directed against different epitopes than those in patients with transient allergy. For a topic as important as this one, new areas of technological developments will likely have a significant impact, to provide more accurate methods of diagnosing useful information to patients about the likely course of their seafood allergy over the course of their childhood and beyond.     

Parvalbumin – the major tropical fish allergen

Fish allergy is common in countries where consumption is high. Asian nations are amongst the world's largest consumers of fish but the allergen profiles of tropical fish are unknown. This study sought to evaluate the allergenicity of four commonly consumed tropical fish, the threadfin ( Polynemus indicus ), Indian anchovy ( Stolephorus indicus ), pomfret ( Pampus chinensis ) and tengirri ( Scomberomorus guttatus ). Immunoglobulin E (IgE) cross-reactivity with parvalbumin of cod fish (Gad c 1), the major fish allergen, was also studied. Detection of tropical fish and cod specific-IgE was performed by UniCap assay, and skin prick tests were also carried out. The IgE-binding components of tropical fish were identified using IgE immunoblot techniques, and cross-reactivity with Gad c 1 was assessed by ELISA inhibition and IgE immunoblot inhibition. Clinically, nine of 10 patients studied were allergic to multiple fish. All patients exhibited detectable specific-IgE to cod fish (10 of 10 skin prick test positive, eight of 10 UniCap assay positive) despite lack of previous exposure. The major allergen of the four tropical fish was the 12-kDa parvalbumin. IgE cross-reactivity of these allergens to Gad c 1 was observed to be moderate to high in the tropical fish studied. Parvalbumins are the major allergens in commonly consumed tropical fish. They are cross-reactive with each other as well as with Gad c 1. Commercial tests for cod fish appear to be sufficient for the detection of tropical fish specific-IgE.     

Question 6: What is the use of allergy testing in children with asthma?

Disagreement exists between asthma guidelines on the routine use of allergy testing in the diagnostic work-up of a child with persistent asthma, although the important role of inhalant allergy in the pathophysiology of asthma and allergic rhinitis is undisputed. The usefulness of screening for inhalant allergies in asthma is connected to the efficacy of allergen reduction measures and specific immunotherapy, both of which appear to be more effective in children than in adults. Allergen-specific exposure reduction recommendations are therefore an essential part of childhood asthma management. Such recommendations should be guided by appropriate diagnosis of inhalant allergy, based on a structured allergy history and results of sensitization tests. Specific IgE testing and skin prick testing show comparable results in identifying clinically important sensitizations. Although a therapeutic medication trial can be started pragmatically in children with asthma without diagnosing their inhalant allergy, we recommend making or excluding an accurate diagnosis of inhalant allergy.     

婴幼儿鸡蛋与牛奶过敏食物皮肤点刺试验的诊断价值

目的 通过对皮肤点刺试验疹团平均直径与开放性食物激发试验的相关性研究,获得有确诊食物过敏价值的皮肤点刺试验界值点,为简化临床诊断程序提供依据.方法 采用前瞻性研究,选择重庆医科大学附属儿童医院儿保科可疑食物过敏儿童173名,均进行皮肤点刺试验及开放性食物激发试验.测量并记录皮肤点刺试验疹团平均直径,通过开放性食物激发试验确诊食物过敏患儿.采用SPSS 13.0软件包进行统计学处理.将开放性食物激发试验作为诊断的金标准,通过四格表计算疹团平均直径的敏感度、特异度、阳性预测值及阴性预测值.通过受试者工作特征曲线及曲线下面积对疹团平均直径诊断价值进行评价;同时获取具有100%诊断价值的平均直径界值点.结果 173名婴幼儿年龄范围1～24个月,平均(9.39±5.67)个月共进行271次食物激发试验(其中阳性结果123次),99例婴幼儿被确诊为食物过敏.食物激发试验诱发症状主要表现为皮肤症状(87.0%),其次是胃肠道症状(9.8%).蛋白、蛋黄、牛奶皮肤点刺试验的受试者工作特征曲线的曲线下面积分别为0.794、0.804及0.904.当皮肤点刺试验疹团平均直径≥3 mm时,敏感度在71%～87%之间,特异度在31%～57%之间.当蛋白、蛋黄、牛奶皮肤点剌试验疹团平均直径分别≥8.5、5.5、5.5 mm时,皮肤点刺试验对食物过敏的诊断准确率可达100%.结论 皮肤点刺试验疹团平均直径对食物过敏的临床诊断准确性较好,通过其100%诊断界值点,可避免部分可疑食物过敏患儿进行食物激发试验.

Abstract：

Objective Mean diameter is the most common used parameter for wheal response assessment after skin prick test.This study aimed to investigate the diagnostic capacity of mean diameter according to the outcome of oral food challenge, and to determine the cut-off points that could render food challenges unnecessary.Method Data of 173 children referred to the Division of Primary Child Health Care for the evaluation of suspected food allergy were prospectively studied.All children underwent skin prick test and open food challenge to the relevant food(s) in clinic.The mean wheal diameter of skin prick test was measured, and open food challenge was performed to confirm food allergy. The SPSS software package version 13.0 for windows ( SPSS, Chicago, IL,USA) was used for all statistical analysis.Open food challenge was taken as the gold standard for diagnosis.Diagnostic capacity of skin prick test, including the sensitivity, specificity, positive predictive value, negative predictive value, was calculated by cross-table.In addition, receiver operating characteristic curve ( ROC ) was plotted and area under the curve ( AUC ) was calculated to quantify the accuracy of the parameter.Result For the 173 children,271 open food challenges were performed with egg white, egg yolk and cow's milk, In which 123 were positive, 99 children were diagnosed as food allergy.Cutanuous symptoms ( 87.0% ) were most common, followed by gastrointestinal symptoms (9.8% ).The AUC of mean diameter was 0.794 for egg white, 0.804 for egg yolk and 0.904 for cow's milk.The sensitivity of skin prick test with a cut-off value of ≥3 mm was ranged from 71% to 87%,while the specificity was between 31% and 57%.The authors also defined food specific skin prick test mean diameters that were 100% diagnostic for allergy to egg white ( ≥8.5 mm), egg yolk ( ≥5.5 mm), cow's milk ( ≥5.5 mm).Conclusion Predictive decision points for a positive outcome of food challenges can be calculated for egg and cow's milk using mean diameter.It may help to simplify the diagnostic procedure of food allergy.     

Skin test and RAST in children allergic to common allergens

Ninety children with bronchial asthma were evaluated for the presence of house dust, house dust mite. Aspergillus fumigatus and milk allergy in vivo by prick test (skin test) and in vitro by RAST. Of the 20 children tested for house dust allergy 12 were positive by skin test and six by RAST. Only six were positive by both methods. Of 25 children tested for house dust mite, 16 were positive by skin test, 13 by RAST and 11 by both methods. Of 35 children tested for aspergillus fumigatus, 25 were positive by skin test, 19 by RAST and 11 were positive by both methods. In the case of 10 children under three years of age with known hypersensitivity to milk, all were negative by prick test and three were moderately positive by RAST method. The correlation of skin test with RAST was 65% for house dust, 72% for house dust mite, 37% for aspergillus fumigatus and 70% for milk. Overall correlation of skin test with RAST was 56·7%.     

Definitive diagnosis of nut allergy.

OBJECTIVE: To compare findings of tests for nut allergy in children. DESIGN: Retrospective survey of a clinical practice protocol. SETTING: Children's hospital paediatric outpatient clinic. SUBJECTS: 96 children referred by general practitioners and accident and emergency doctors over 27 months (1994-96). MAIN OUTCOME MEASURES: Allergic manifestations (generalised urticarial rash, facial swelling, bronchospasm, anaphylactic shock, vomiting on three occasions) related to specific nut IgE concentrations and following touch, skin prick, or oral ingestion of nuts. RESULTS: 16 children from a sample of 51 who were tested for nut allergy had no reaction to an oral challenge. Positive IgE against peanuts was found in nine of these 16 children. CONCLUSIONS: Skin prick testing and IgE measured by radioallergosorbent testing are inadequate tests for nut allergy. The definitive diagnostic test for nut allergy in the hospital setting is direct oral challenge.     

DOG HYPERSENSITIVITY IN ASTHMATIC CHILDREN

ABSTRACT. The occurrence of dog hypersensitivity in 203 unselected asthmatic children was investigated by means of the skin prick test, the provocation test and RAST. The history of past and present exposure to dogs, symptoms in contact with dogs, and the effects of pet avoidance were examined. The amount of dog dander antigens was analyzed by counter-immunoelectrophoresis from dust samples from 67 homes. A history of past or present dog hypersensitivity was obtained from 120 subjects (59%). A positive (≧++) prick test reaction was observed in 113 (56%), a positive provocation test result in 84 (41%) and a RAST class ≧ 1 in 140 (69%). The serum levels of IgE antibodies to dog dander correlated significantly with serum total IgE and the frequency of asthmatic attacks. The occurrence of dog allergy was not significantly associated with past or present exposure to dogs at home. However, the children who were exposed to dogs during the first year of life had dog allergy more often than those with late or without exposure. Significant amounts of dog dander antigen were also found in dust samples from homes where dogs have never been kept. Serum samples from previous years were available from 24 patients. Rising or steadily high levels of IgE antibodies to dog dander were observed even in subjects who strictly avoided dogs. The results show that dog hypersensitivity is an important cause of allergic disorders in asthmatic children, and that the common presence of dog dander antigens in our environment may induce dog allergy even without direct exposure to dogs.     

口服螨免疫疗法辅助治疗儿童哮喘疗效观察

目的　观察口服螨免疫疗法对哮喘儿童的辅助治疗作用。方法　应用螨口服脱敏液安慰剂双盲试验对２３ 例哮喘患儿进行１２ 个月的临床观察,并测定血清螨特异性ＩｇＥ（ＳＩｇＥ） 、螨皮肤变应原试验和肺功能检查。结果　服用螨脱敏液的患儿,血清螨ＳＩｇＥ在用药后６ 个月时下降并持续到１２ 个月,治疗１２ 个月时肺功能明显改善,咳嗽发作次数减少,无用药不良反应。结论　口服螨免疫疗法作为吸入激素的辅助疗法治疗螨过敏的哮喘患儿有一定效果。     

Anaphylaxis after prick‐to‐prick test with fish

Skin prick testing is the diagnostic procedure for allergies and is considered to be safe. It is usually performed using the prick and the prick‐to‐prick method. Herein is described a pediatric case of anaphylaxis during prick‐to‐prick testing with raw fish in a patient who had consumed fish without any systemic allergic reactions beforehand, to illustrate that skin prick testing should be carefully planned and performed with caution in order to avoid potentially serious risks for the patient.     

Cow's milk allergic children can present sensitisation to probiotics

Aim: To evaluate sensitivity to different probiotics in children with cow's milk allergy.
Methods: Eighty-five patients (age range: 4 months –12 years) presenting atopic dermatitis (AD) were enrolled. Skin prick test (SPT) responses to three different probiotics preparations (Fiorilac®, Dicoflor® and Reuterin®) were evaluated in addition to relevant food allergens.
Results: Thirty-nine patients out of 85 (45.8%) had a positive skin response to prick test for cow's milk (3 with reaction <3 mm). Of the thirty-six patients with a cow's milk weal reaction >3 mm, twenty-eight (77.8%) had a skin response to Fiorilac®, four patients (11%) to Dicoflor® and four (11%) to Reuterin®. The proportion of SPT reaction to all the investigated probiotics preparations was significantly lower than cow's milk (r = 9.406; p = 0.002). A significantly higher sensitization was observed for Fiorilac® versus Dicoflor® (r = 30.916; p < 0.001) and versus Reuterin® (r = 34.133; p < 0.001).
Conclusion: Probiotic use in patients with cow's milk allergy has to be limited to products that do not contain milk. This should be clearly reported in the label. In selected patients, it is advisable to perform a screening SPT with the product to evaluate its potential contamination with milk.