Phenotypes of IgE-mediated food allergy in Turkish children

Data on food allergy-related comorbid diseases and the knowledge on factors associating specific food types with specific allergic outcomes are limited. The aim of this study was to determine the clinical spectrum of IgE-dependent food allergy and the specific food-related phenotypes in a group of children with IgE-mediated food allergy. Children diagnosed with IgE-mediated food allergy were included in a cross-sectional study. IgE-mediated food allergy was diagnosed in the presence of specific IgE or skin-prick test and a consistent and clear-cut history of food-related symptoms or positive open provocation test. Egg (57.8%), cow's milk (55.9%), hazelnut (21.9%), peanut (11.7%), walnut (7.6%), lentil (7.0%), wheat (5.7%), and beef (5.7%) were the most common food allergies in children with food allergy. The respiratory symptoms and pollen sensitization were more frequent in children with isolated tree nuts-peanut allergy compared with those with egg or milk allergy (p < 0.001); whereas atopic dermatitis was more frequent in children with isolated egg allergy compared with those with isolated cow's milk and tree nuts-peanut allergy (p < 0.001). Children with food allergy were 3.1 (p = 0.003) and 2.3 (p = 0.003) times more likely to have asthma in the presence of allergic rhinitis and tree nuts-peanut allergy, respectively. Interestingly, children with atopic dermatitis were 0.5 (p = 0.005) times less likely to have asthma. Asthma (odds ratio [OR], 2.3; p = 0.002) and having multiple food allergies (OR, 5.4; p < 0.001) were significant risk factors for anaphylaxis. The phenotypes of IgE-mediated food allergy are highly heterogeneous and some clinical phenotypes may be associated with the specific type of food and the number of food allergies.     

Egg and milk allergy in asthmatic children: assessment by immulite allergy food panel, skin prick tests and double-blind placebo-controlled food challenges

There is a perception that asthmatic symptoms may be worsoned by ingestion of certain foods. This study aimed to investigate whether ingestion of cow's milk or egg might induce respiratory symptoms in asthmatic children. Fifty asthmatic children aged 1.5 to 6 years old, with positive Immulite Food Panel FP5 test results were included in the study. Fifty healthy children within the same age group were accepted as control group. Total serum IgE levels were measured and skin prick tests for food allergens including milk and egg were performed. All of the subjects underwent oral, double-blind, placebo-controlled challenge with fresh egg and cow's milk powder. Two medical histories were confirmed by double-blind, placebo-controlled challenge in 9 patients (22.2%). Skin prick tests were positive in 9 patients (18%) with milk and 18 patients (36%) with egg antigen. Two children experienced wheezing, one after ingesting milk and the other after egg challenge (4%). In the control group no positive reactions were seen with egg or milk challenges. Our findings confirm that food allergy can elicit asthma in children, but its incidence is low, even with major allergens such as egg and milk. History, specific IgE determinations and skin prick tests are not reliable in diagnosing food reactions. Since any diet can cause rapid deficiencies in infancy, diet restrictions must not be applied, without performing double-blind, placebo-controlled challenge.     

Hypereosinophilia, hyper-IgE syndrome, and atopic dermatitis in a toddler with food hypersensitivity.

We describe a 20-month-old girl with hypereosinophilia, hyper-immunoglobulin (Ig) E syndrome, and atopic dermatitis. Her peripheral eosinophil count and IgE plasma levels were 2.65 x 10(9)/L and 6702 IU/mL, respectively. Specific IgE levels for a variety of foods and inhalants were high and single-blind food challenges were positive for cow's milk, hen's egg, oat, wheat, and soy. When the patient received an extensively hydrolyzed milk formula, an exclusion diet, and 2 mg/kg of prednisone daily, the atopic dermatitis partially improved. Further improvement was observed with 1 mg/kg of azathioprine daily. Long-term clinical response was satisfactory.We suggest that food hypersensitivity should be ruled out in patients with hypereosinophilia, hyper-IgE syndrome, and atopic dermatitis. Azathioprine may be a good therapeutic alternative for treatment in such cases.     

Quoi de neuf en allergologie pédiatrique en 2005 ? Partie 4. Allergie cutanée,alimentaire, médicamenteuse et aux insectes (Une revue de la littérature internationale d'octobre 2004 à octobre 2005)

Allergological work-up and treatment of french children with atopic dermatitis have been the subject of a recent consensus. Food avoidance is useless for prevention of atopic dermatitis, and should be indicated in children with severe atopic dermatitis associated with food allergy only. Exposure, sensitization and allergy rates to nuts increase with age, and avoidance of nuts (even tolerated) is recommended in young children allergic to one or several nuts to prevent the risk of sensitization and allergy to an increasing number of nuts. Threshold values of skin prick-tests and specific IgE determinations with a 90-100% predictive value for food allergy are highly variable from one study to another one, and depend on numerous factors such as age of the children, the allergens used, etc. The diagnostic value of patch-tests and skin application food tests remains controversial. Treatment of food allergy is based on the eviction of the allergenic foods. However, probiotics and « desensitization » to foods may be efficacious in some patients. In children that have outgrown their food allergy, tolerance should be maintened by regular consumption of the foods. However, the parents should be informed that relapses requiring an emergency treatment may occur. Finallly, in children as in adults, repeated mosquito bites induce a desensitization, and most children outgrow their allergy between five to fourteen years.     

Food Allergy and Atopic Dermatitis: How Are They Connected?

Food allergy predominantly affects children rather than adults with atopic dermatitis (AD). Early food sensitization has been found to be significantly associated with AD. Three different patterns of clinical reactions to food allergens in AD patients have been identified: 1) immediate-type symptoms, 2) isolated eczematous late-type reactions, and 3) combined reactions. Whereas in children, allergens from cow’s milk, hen’s egg, soy, wheat, fish, peanut, or tree nuts are primarily responsible for allergic reactions, birch pollen–related food allergens seem to play a major role in adolescent and adults with AD in Central and Northern Europe. Defects in the epidermal barrier function seem to facilitate the development of sensitization to allergens following epicutaneous exposure. The relevance of defects in the gut barrier as well as genetic characteristics associated with an increased risk of food allergy remain to be further investigated. Many studies focus on sufficient strategies of prevention, which actually include breastfeeding or feeding with hydrolyzed formula during the first 4 months of life.     

Are the most common food allergens in an Iranian atopic population compatible with worldwide reports? A systemic review and meta-analysis with molecular classification of frequent allergens

BackgroundUndesirable immunological responses to alimentary allergens are one of the hallmarks of atopic diseases. The prevalence of common food allergens is dissimilar among different communities with distinct nutritional habits and genetic characteristics.AimTo assess the prevalence of the most common food allergens in Iran, using different reliable studies.MethodsAll studies determining sensitization to common food allergens that were indexed in PubMed, Web of Science, Google Scholar, ProQuest, Scopus, Iran Medex, and Magiran were included in this review. To perform a meta-analysis, STATA 14 and metaprop command was applied. A logistic-normal random-effects model with Freeman–Tukey double arcsin transformation was applied to combine the findings of different studies and evaluate their heterogeneity. Random pooled estimate (ES) (pooled prevalence), 95% confidence interval (95% CI) and p-value were determined.ResultsA total of 23 studies with data from a total of 6126 children and adults met the inclusion criteria for entering this meta-analysis. The respective pooled prevalence of a positive family history of allergy and positive specific IgE to at least one food allergen was 72% (95% CI: 66–77%) and 41% (95% CI: 33–49%), respectively. Our results in the total population revealed that allergic sensitization to egg yolk, cow’s milk (CM), egg white, and wheat were 25% (95% CI: 16%–35%), 24% (95% CI: 19–29%), 23% (95% CI: 18%–28%), and 9% (95% CI: 6%–14%), respectively. Walnut, peanut, and soybean sensitization was detected in 23% (95% CI: 17%–31%), 23% (95% CI: 13%–33%), and 20% (95% CI: 12%–28%) of patients, respectively. Random pooled ES for sensitization to shrimp and fish was 32% (95% CI: 21–45%) and 12% (95% CI: 6–20%), respectively. The result of analysis in different age groups revealed that allergic sensitization to milk, egg white, and egg yolk declines in higher age groups; while shrimp sensitization increases in older patients. In patients with atopic dermatitis, egg white was the most frequent food allergen 29% (95% CI = 18–42%); while wheat was the least frequent 8% (95% CI = 4–14%).ConclusionsConsidering the prevalence of different food allergens, the results of the current meta-analysis revealed that egg yolk and cow’s milk had the second and third rate after shrimp, respectively. The high prevalence of sensitization to shrimp may be attributed to its high consumption in coastal areas and/or cross-reactivity of shrimp with some aeroallergens such as mites.     

Etiologic implication of foods in atopic dermatitis: evidence against

Atopic dermatitis is a typical chronic inflammatory skin disease that usually occurs in individuals with a personal or family history of atopy. Children with atopic dermatitis frequently present IgE-mediated food sensitization, the most commonly involved foods being egg and cow's milk. However, controversy currently surrounds whether food allergy is an etiological factor in atopic dermatitis or whether it is simply an associated factor, accompanying this disease as one more expression of the patient's atopic predisposition. Approximately 40 % of neonates and small children with moderate-to-severe atopic dermatitis present food allergy confirmed by double-blind provocation tests but this allergy does not seem to be the cause of dermatitis since in many cases onset occurs before the food responsible for allergic sensitization is introduced into the newborn's diet.Studies of double-blind provocation tests with food in patients with atopic dermatitis demonstrate mainly immediate reactions compatible with an IgE-mediated allergy. These reactions occur between 5 minutes and 2 hours and present mainly cutaneous symptoms (pruritus, erythema, morbilliform exanthema, wheals) and to a lesser extent, digestive manifestations (nausea, vomiting, abdominal pain, diarrhea), as well as respiratory symptoms (wheezing, nasal congestion, sneezing, coughing). However, these reactions do not indicate the development of dermatitis.Some authors believe that responses to the food in provocation tests may also be delayed, appearing mainly in the following 48 hours, and clinically manifested as exacerbation of dermatitis. However, delayed symptoms are difficult to diagnose and attributing these symptoms to a particular foodstuff may not be possible.Delayed reactions have been attributed to a non-IgE-mediated immunological mechanism and patch tests with food have been proposed for their diagnosis. In our experience and in that of other authors, the results of patch tests with cow's milk do not seem very specific and could be due, at least in part, to the irritant effect of these patches on the reactive skin of children with atopic dermatitis.The involvement of foods in atopic dermatitis will always be difficult to demonstrate given that an exclusion diet is not usually required for its resolution. Food is just one among several possible exacerbating factors and consequently identification of its precise role in the course of the disease is difficult. Further double-blind prospective studies are required to demonstrate the effectiveness of exclusion diets in the treatment of atopic dermatitis.Apart from the controversy surrounding the etiological role of foods, the most important point in atopic dermatitis is to understand that the child is atopic, that is, predisposed to developing sensitivity to environmental allergens; in the first few years of life to foods and subsequently to aeroallergens. Consequently, possible allergic sensitization to foods should be evaluated in children with atopic dermatitis to avoid allergic reactions and to prevent the possible development of allergic respiratory disease later in life.     

Management of atopic dermatitis: practical guidelines suggested by the conclusion of systematic assessment in 500 children

Allergic management of AD may be worthwhile since allergy may trigger the disease. A systematic evaluation of sensitizations overtime and study of their clinical involvement in 500 children with AD was carried out, including minor, moderate, and severe patients (defined by clinical scores). Standardized methods assessed the possibility of contact dermatitis as well as IgE dependant allergies. Contact dermatitis concerned fragrances and nickel. Contact dermatitis was observed in minor and moderate AD with a progressive increase: 11% of children under 2 years and 58% in those over 15 years of age. Later in older children, sensitization to cosmetics and occupational allergens occurred in close connection with the specific environment. As for IgE sensitization, investigation should be electived advised in moderate and severe AD. Inhalant allergen sensitization was observed in 66% in moderate AD and 93% in severe AD in the group of 7 or 15 years. Clinical confrontation was a better indicator of cutaneous involvement than atopen patch-test. It mainly concerned respiratory symptoms. In severe AD, food allergy was constantly observed and presented as a marker for severe atopic dermatitis. The main trophallergen differ according to the age and cultural habits: in children under 2 years of age, eggs, peanuts, milk, fish were the main offending agents. Later, main trophallergens were wheat flour, shellfish. Although spontaneous decrease of food allergy is sometimes observed, it must be pointed out that food allergy may still persist as a triggering factor in teenagers as well as in adult-hood. The allergologic diagnosis of atopic dermatitis should not focus on IgE dependent sensitization without patch testing.     

Etiologic implication of foods in atopic dermatitis: evidence in favor

Some of the immunopathologic mechanisms involved in IgE responses are currently being identified; Th2 lymphocytes are known to be activated in patients with atopic dermatitis with subsequent production of the cytokines interleukin (IL)-4 and IL-5, which are responsible for IgE production and eosinophil recruitment. Nevertheless, T cell activation in this disease takes place in two phases. In the first phase, Th2 cells are activated and IL-4, IL-5 and IL-13 are produced; this first stage is produced with the initial activation induced by the antigen. In the second phase there are chronic lesions, Th1 lymphocytes are activated and IFg is produced. This chronic phase is associated with the presence of eosinophils and macrophages that produce IL-12.Numerous articles have demonstrated food sensitization to be an etiopathogenic factor in atopic dermatitis. The prevalence of sensitization varies, depending on the patient's age and the severity of the disease. Children with moderate-to-severe atopic dermatitis have been observed to have a positive skin test and high IgE concentrations to various foods. Nevertheless, a positive skin test to foods in such children does not always implicate these foods as the cause of the clinical manifestations; moreover, in children showing subsequent tolerance to these foods, skin tests can sometimes remain positive and high levels of specific IgE can persist. It is now known that IgE not only participate in the degranulation of mastocyte cells but also in reactions mediated by T cells and other antigen-presenting cells (dendritic cells) which have high-affinity receptors for IgE.The immediate IgE response is well known but it is also known that in addition to the immediate response, a delayed response is also involved, evidenced by the presence of antigen-specific T cells to foods or other allergens such as inhalant allergens. After a strict exclusion diet, children with atopic dermatitis and sensitivity to foods such as milk, egg, flour and soya can develop tolerance; for this reason provocation tests with the food in question should be repeated every 2-3 years. In children with sensitivity to other foods such as dried fruits, fish, and shellfish, sensitivity can sometimes persist into adulthood without tolerance being achieved. In conclusion, there are two groups of children with atopic dermatitis. One group consists of those with atopic dermatitis (allergic disease), which is characterized by early development, high IgE titers, the presence of antigen-specific IgE to allergens and a family history of atopy and which is clinically moderate or severe. Early diagnosis and treatment are important in these children, as is the prevention of progression of the disease to bronchial asthma. The other group consists of children whose dermatitis is clinically atopic in terms of its localization and morphology, who have no demonstrable allergic disease and whose management differs from that in children presenting allergic disease     

Role of aeroallergens in the etiopathogenesis of atopic dermatitis

Atopic dermatitis is a chronic relapsing inflammatory skin disease. It is most frequent in childhood and its clinical manifestations vary with age. The etiopathogenic mechanisms that explain this process are still poorly understood; several studies performed in adults speculate on the possible role of aeroallergens through direct contact with the skin but, because the etiology of this disease varies with age, studies in children of different ages are required.Aims: (i) To determine whether children with atopic dermatitis are sensitized to inhalant allergens. (ii) To determine whether these inhalant allergens cause dermatitis or whether they provoke allergic respiratory disease (asthma, rhinitis) concomitant with atopic dermatitis. (iii) To evaluate whether sensitization to a particular allergen takes place at any age or whether there are differences according to age.Material and methods: This study was performed in the following groups: (i) 64 children with atopic dermatitis, divided into two subgroups, one consisting of 37 children who also presented allergic respiratory disease (asthma, rhinitis) (AR) and another subgroup of 27 patients who presented atopic dermatitis only. (ii) Control group: eight children who presented AR only, to determine whether this group reacted to patch testing with inhalant allergens. (iii) Control group: seven healthy children to rule out non-specific positive tests in the non-atopic population. All groups were divided by age according to the phases of atopic dermatitis: early childhood phase (< 2 years): 21, childhood phase (2-10 years): 37, adolescent phase (> 10 years): 21. In all children total serum IgE determination (RIA), allergen-specific IgE determination (RAST), prick- and patch test were performed. In the three tests the same allergens were used, consisting of the usual components of standardized inhalant and food allergens. When the results of patch testing were positive, biopsy and histopathological analysis were performed and monoclonal antibodies were used to determine reproducibility of the eczematous lesion.Results: Sensitization was found to differ among patients with atopic dermatitis according to whether they presented respiratory symptoms and according to age with a clear predominance of food sensitization in the group aged less than 2 years. In the group aged 2-10 years, mixed sensitization predominated, mainly because of simultaneous respiratory involvement, but it is highly probably that inhalant allergens participate in the etiopathogenesis of atopic dermatitis. In children aged more than 10 years sensitization to inhalant allergens predominated as most presented respiratory symptoms. Patch testing was positive in 34.3 % of patients with atopic dermatitis and approximately half were positive to dust mites. The patch test is of great diagnostic value in atopic dermatitis and none of the tests were positive in the control group. All the biopsies of patch tests with inhalant allergens reproduced the lesions typical of eczema, demonstrating their involvement in the etiopathogenesis of dermatitis.     

Risk of allergy to food proteins in topical medicinal agents and cosmetics

The risk of allergy to food proteins in cosmetics and topical medicinal agents is poorly evaluated. IgE dependent contact urticaria and contact dermatitis are observed. Eleven cases (7 infants and 4 women) are reported. Wheat, egg, oats, milk, peanut proteins are incriminated by prick-tests or atopy patch-tests. Cases are related to a previous food allergy and other ones may indicate primary sensitization to topical creams mainly used for skin care of atopic dermatitis. A consecutive exercise induced anaphylaxis to wheat and a long lasting sensitization to wheat have been observed. A clear and accurate identification of food allergens in cosmetics and topical agents is necessary. Given the hyper-permeability of infant skin, topical products containing food proteins of known allergenicity are contra-indicated for neonates, and for infants with atopic dermatitis, which may be associated with skin hyper-permeability.     

Asthma Symptoms and Bronchial Reactivity in School Children Sensitized to Food Allergens in Infancy

Food allergy in infancy usually disappears but is followed primarily by respiratory allergy. We hypothesized that children allergic to common food allergens in infancy are at increased risk of wheezing illness and bronchial hyperresponsiveness during school age. In a case-control study 69 children 7.2 to 13.3 years of age allergic to egg (N = 60) and/or fish (N = 29) in early life (first 3 years) who attended our allergy outpatient clinic were recruited. They received follow-up for 1 year and were evaluated by parental questionnaire, skin prick testing, spirometry, and metacholine bronchial challenge. Another 154 children (70 sensitized to inhaled allergens) recruited selectively from a general population sample with no history of food allergy during their first 3 years served as control subjects. Twenty-three children (38.3%) maintained their sensitization to egg and 19 (65.5%) to fish; the prevalence of sensitization to ≥ 1 inhaled allergen(s) increased from 59.4% to 71% during childhood. Current asthma symptoms were reported more frequently in the study group than in either control groups, sensitized to inhaled allergens and non-sensitized. Children of the study group showed a significantly increased frequency of positive response to metacholine bronchial challenge compared to the control group as a whole; the difference was statistically indicative when study groups separately were compared to the sensitized control subjects. Multivariate logistic regression analysis showed that bronchial hyperresponsiveness, as well as reported current asthma symptoms were associated with early wheezing and early sensitization to inhaled allergens but not with atopic dermatitis in infancy or persistence of egg or fish allergy. Children allergic to egg or fish in infancy are at increased risk for wheezing illness and hyperactive airways in school age; asthma and bronchial hyperresponsiveness development is mostly determined by wheezing and senzitization to inhaled allergens in early life regardless of atopic dermatitis in infancy or retention of food allergy.     

The problems of the child with food allergies

In France, about 20% of schoolchildren are suffering from allergic diseases. Food allergy (FA) is steadily increasing for the last 20 years. Actually, 400,000 children are suffering from FA. Prevalence has increased this last decade. Frequency is estimated about 10% and increased twofold within 5 years. In France, the most common food allergens are: hen's egg (35%), peanut (24%), cow's milk (8%), mustard (6%), and fish (4%). Other food allergens as hazelnut, kiwi, wheat, sesame, seafood, and lupin. Cross reactivities to exist between fruits, vegetables pollen, latex and are more and more frequent. Multiple food allergies have recently been described.     

"Atopy patch tests" in the diagnosis of delayed food hypersensitivity

The prevalence of atopic diseases is increasing worldwide. Food allergies are the earliest manifestation of atopy. Atopic eczema affects about 18% of infants in the first 2 years of life and the main cause is allergy to multiple foods. A strong association has been shown between atopic eczema and IgE mediated allergy to milk, egg or peanut, but more than two-thirds of patients intolerant to food proteins have no evidence of IgE sensitization to the relevant food protein. Recently, patch testing with proteins has been found to be helpful in diagnosing food allergy in cases where skin prick tests and estimation of specific antibodies have failed. The methodology of atopy patch test (APT) is unstandardized, and contradictory results have been reported. In contrast to the more standardized APT methodology with aeroallergens, the sensitivities and specificities of food allergens can easily be estimated with food challenge tests. With multiallergic children adding of APTs to the skin prick tests and specific antibody estimation tests give more information for planning a wide enough elimination diet to get the skin and gastrointestinal tract symptomless in order to perform the challenge test which remains the only reliable test for food allergy. Standardization of the APT materials and reading procedure will add to the reliability of this new test method.     

Effect of extensively hydrolyzed milk formula on growth and resistance to bronchitis and atopic dermatitis in infants and toddlers.

OBJECTIVE: This study aimed to evaluate the adverse effects of extensively hydrolyzed milk formula on growth in infants and toddlers. METHODS: Prospectively, 45 infants and toddlers with a positive history of cow's milk allergy confirmed by positive skin prick test and high IgE levels for either alpha-lactalbumin, beta-lactoglobulin, or casein and positive single-blind food challenge received extensively hydrolyzed milk formulas for 1 year. Sex-normalized percentiles of heights and weights of infants and toddlers before their enrollment in the study were compared to those at the end of the study. The contribution of breastfeeding, early use of bottle feeding and intake of adapted or special milk formulas, and history of bronchitis and atopic dermatitis on toddlers' growth were also evaluated by multivariate analysis. RESULTS: Similar percentiles of the children's weight and height were observed at the beginning of the study and 1 year later. According to the multivariate analysis, sex, breastfeeding, early bottle feeding, ingestion of adapted or special milk formulas, atopic dermatitis, and bronchitis were not correlated with either the children's weight or height at diagnosis of the allergy or at 1 year of follow-up (P > .10). Weights and heights were not different between toddlers who had atopic dermatitis or bronchitis during the study period and those who did not. CONCLUSIONS: Growth of infants and toddlers with cow's milk allergy was not affected by the intake of extensively hydrolyzed milk for 1 year. Atopic dermatitis and bronchitis did not appear to have any deleterious effect on these children's growth.     

What makes a child allergic? Analysis of risk factors for allergic sensitization in preschool children from East and West Germany.

Earlier epidemiologic studies within Germany found a higher frequency of allergic sensitization in West Germany. The reasons for that and the role of environmental factors in the process of allergic sensitization are not fully understood. This study aimed to determine the prevalence of positive skin-prick test results 5 years after unification and to investigate risk factors for allergic sensitization in preschool children. A total of 1235 children (5-6 years) from two West and five East German locations were skin-prick tested after the compulsory school entrance examination. Six common aero- (birch, grass, mugwort pollen, cat, HDM, alternaria) and two food allergens (egg, milk) were used and additional information was obtained by questionnaire. Of the tested children 23.3% exhibited at least one positive reaction. The prevalence of sensitization to the single allergens was as follows: grass (14.4%), birch (6.6%), mugwort pollen (4.5%), cat (8.5%), HDM (5.5%), alternaria (4.9%), egg (2.8%), and milk (3.9%). In the crude analysis significantly more children were sensitized in the East German city Magdeburg (40.2%) compared to the West German control region Borken (23.5%) (OR 2.20, CI 1.47-3.29). Dampness and visible molds were reported in 8.8% of all households, but significantly more often for East German apartments (10.3% versus West Germany 1.9%, OR 5.85, CI 2.55-16.53). Dampness and molds were associated with a higher frequency of sensitizations (40.6% versus 27.6% in unaffected homes). After controlling for sex, parental atopy, SES, family size, and smoking during pregnancy, this association remained statistically significant (OR 1.93, CI 1.19-3.12). With regard to single allergens, dampness and visible molds were significantly associated with sensitization to HDM (OR 3.37, CI 1.63-6.96), cat (OR 3.19, CI 1.11-5.74), and mugwort pollen (OR 2.86, CI 1.29-6.35). In addition, family size was inversely and linearly associated with the frequency of sensitization (OR for four, three, and two-person households: 1.10 (0.74-1.63), 1.57 (1.06-2.42), 2.70 (1.39-5.24), respectively, when compared to family size of five or more). Neither parental predisposition for atopic diseases nor parental education level influenced the prick test reactivity. We conclude that in addition to genetic predisposition, environmental factors like indoor climate and probably infectious stimuli (family size) play an important role in the process of allergic sensitization in children.     

Anaphylaxis to pine nuts and immunological cross-reactivity with pine pollen proteins.

Despite the wide use of pine nuts, the fruit of Pinus pinea, only a few reports of allergic reactions to them have been published. We present herein a case of food allergy to pine nuts in a patient who showed no clinical symptoms to pine pollen despite the presence in her serum of specific IgE antibodies. In order to verify whether the reaction against pine nuts was IgE mediated, specific IgE against pine nuts and pollen were evaluated by skin-prick test, prick by prick and RAST. Immunoblotting and immunoblotting-inhibition were used to evaluate the allergenic components of both extracts and their cross-reactivity. Prick by prick with fresh pine nuts and RAST with pine nut and pine pollen extracts showed that the patient had high levels of specific IgE against both extracts. Immunoblotting experiments showed the presence in serum of IgE antibodies against several components in pine nuts and pollen. Immunoblotting-inhibition experiments demonstrated the presence of some cross-reacting components. These data confirm the existence of food allergy induced by pine nuts. This sensitization to pine nuts developed with no symptoms of pine pollinosis. Development of pollinosis may require a longer time of exposure to allergens. Based on the cross-reactivity between pine nut and pine pollen extracts, cosensitization to these two allergens could be possible.     

The role of food allergy in atopic dermatitis

Atopic dermatitis (AD) is a chronic, pruritic, inflammatory skin disease affecting more than 10% of all children. Sensitization to foods triggers isolated skin symptoms in about 30% of children. These symptoms include immediate reactions within minutes after ingesting food without exacerbation of AD and early and late exacerbations of AD. It is important to identify clinically relevant sensitizations to foods using skin prick tests, a specific IgE blood test (ImmunoCAP; Phadia, Portage, MI, USA), and double-blind, placebo-controlled food challenges to initiate appropriate dietary interventions and avoid unnecessary dietary restrictions. Children with AD triggered by food allergens demonstrate a distinct immune response upon stimulation of their peripheral blood mononuclear cells with food allergen. A defective skin barrier and increased intestinal permeability appear to facilitate allergen sensitization. Appropriate skin care to maintain skin barrier function and dietary avoidance of highly allergenic foods during infancy may help to prevent allergen sensitization, thereby reducing the severity of AD and food allergies.     

Contact sensitization in children with atopic dermatitis

Background

Atopic dermatitis is a common illness in childhood. Children with atopic dermatitis are prone to develop cutaneous sensitization due to skin barrier dysfunction.

Cow's Milk Anaphylaxis in Children First Report of Iranian Food Allergy Registry

Cow's milk anaphylaxis is the most common food-induced anaphylaxis in Iranian children. The clinical and laboratory findings of cow's milk anaphylaxis are evaluated in this study. All children who had experienced cow's milk anaphylaxis and had been referred to Immunology, asthma and allergy research center during a 5-year period were considered. After fulfilling a questionnaire, patients underwent measurement of total IgE and cow's milk-specific IgE by Immunocap test and Skin prick test (SPT) with cow's milk extract. Patients with a convincing history and one positive cow's milk-specific IgE test (SPT or Immunocap test) and patients with both positive tests were enrolled, in this study.Out of 49 patients, 59.2% were male. Patients' mean age was 5 years old and their mean age at the time of first attack was 5.7 months (SD = 4.3). Most of the patients have experienced more than one episode of anaphylaxis (79.5%) and in 85.7% of all cases, first attack occurred during the first year of life. Severity grading 1-5 were 2%, 6.1%, 18.4%, 69.4%, 4.1% respectively. Most common manifestations were cutaneous 98%, Respiratory 91.8%, Gastrointestinal 55.1%, Cardiovascular 46.9% and neurologic 46.9% signs and symptoms respectively. Twenty four patients showed positive SPT. Mean total IgE was 239.6±3.3 (IU/mL) and mean cow's milk-specific IgE was 19.28±27.2 (IU/mL). Most patients showed reactions only after ingestion of cow's milk or after dairy foods (81.6%).It is concluded that cow's milk anaphylaxis may happen early in life. Regarding the severity of attacks and remarkable number of patients with several attacks, poor knowledge about this disorder is evident.