Possible consequences of elimination diets in asymptomatic immediate hypersensitivity to fish

A review of food allergy panels and their consequences

Serum immunoglobulin E (IgE) assays to food specific IgE (s-IgE) are useful tools for the confirmation of clinical suspicion of food allergy. However, the specificity of these assays is poor given that sensitization is much more common than clinical food allergy. Therefore, the use of broad panels to assess sensitization to multiple foods often leads to overdiagnosis and unnecessary food avoidance. Unintended consequences that may occur as a result include physical harm, psychological harm, financial cost, opportunity cost, and even worsening of existing health care disparities. Although current guidelines recommend against the use of s-IgE food panel testing, these tests are widely available and frequently used. To limit the negative impacts of s-IgE food panel testing, further work is needed to effectively spread the message that these food panels may cause unintended harm to patients and families.

Eosinophilic esophagitis in children: Updates and practical aspects of management for allergists in a non-tertiary care private practice setup

Background: Eosinophilic esophagitis (EoE) is a chronic immune and/or antigen-mediated disease characterized by eosinophilic infiltration of mucosa (≥15 eosinophils per high power field) without any secondary etiology. Non-immunoglobulin E mediated mechanisms predominate in EoE. Objective: This review concentrated on a stepwise approach for the allergist working in non-tertiary care private practice. Methods: A medical literature search that focused on several areas of the latest developments in the diagnosis and management of EoE was conducted. Results: There has been a steady increase in the prevalence and incidence of EoE. Clinical symptoms can vary from dysphagia to failure to thrive, depending on the age at presentation; some children develop adaptive behaviors to compensate for dysphagia, such as food preferences and slow eating. The diagnosis is based on a high index of clinical suspicion and is confirmed with endoscopy with biopsies after ruling out other causes of esophageal eosinophilia. Treatment options may include dietary therapy, pharmacologic therapies, or combination therapy. Therapeutic options may also include endoscopic dilation for stricturing disease. Conclusion: Providers should be aware of recent recommendation changes in the diagnostic workup, the role of skin-prick testing, and role of the proton-pump inhibitor as first-line therapy for EoE. Also, clinicians should be aware of the emerging role of empiric dietary therapy as a preferable therapeutic option when compared with the testing-directed diet and the elemental diet. Furthermore, topical glucocorticoid therapies are available, and new developing therapies are being investigated. Reevaluation of esophageal mucosa with biopsies is required approximately 2 months after therapy for a response and after a change in therapies to confirm continued resolution.

Factors influencing reintroduction of peanut and tree nuts after negative oral food challenges in children

BACKGROUND

Compliance with reintroduction of foods after a negative oral food challenge (OFC) is variable. Ongoing avoidance of tolerated foods is associated with recurrence of allergy and a reduced quality of life.

OBJECTIVE

To determine the proportion of children who reintroduced peanut or tree nuts after a negative OFC and to describe factors that influenced decisions regarding reintroduction or avoidance of nonallergic (negative) nuts.

METHODS

Families of children that had undergone an OFC for peanut or tree nuts at Sydney Children's Hospital were invited to participate. Consenting families were sent an online questionnaire.

RESULTS

The response rate to the questionnaire was 64%. More than 85% of respondents had introduced all or some of the negative nuts after the OFC and most had maintained at least some regular exposure in the child's diet at the time of the study. The age at diagnosis of the nut allergy and an awareness of the benefit of introducing foods after a negative OFC were significantly (P < .05) associated with introducing negative nuts. There was improved quality of life in those that introduced negative nuts.

CONCLUSION

Most families introduced or attempted to introduce negative nuts after a negative OFC. Educating families on the benefits of introducing foods after a negative OFC result is an important factor contributing to successful reintroduction.

Home-Based Peanut Oral Immunotherapy for Low-Risk Peanut-Allergic Preschoolers During the COVID-19 Pandemic and Beyond

The coronavirus disease 2019 (COVID-19) pandemic has led to the deprioritization of non-emergency services, such as oral food challenges and the initiation of oral immunotherapy (OIT) for food-allergic children. Recent studies have suggested that home-based peanut OIT could be a safe and effective option for low-risk peanut-allergic children. In the period between September 1, 2020, and January 31, 2021, nine preschoolers with a history of mild allergic reactions to peanut underwent home-based peanut OIT. Eight of them (88.9%) completed the build-up phase at home in 11–28 weeks, tolerating a daily maintenance dose of 320 mg peanut protein. During the build-up, six patients (75.0%) reported urticaria, three (33.3%) reported gastrointestinal tract symptoms, and one (14.3%) reported oral pruritis. None of the patients developed anaphylaxis, required epinephrine, or attended emergency services related to OIT. One or two virtual follow-up visits were completed per patient during the build-up phase. Our case series shows that home-based OIT could be offered to the low-risk preschoolers during the COVID-19 pandemic when non-emergency services are limited and could be considered beyond the pandemic, especially for the families living in the rural or remote areas that may otherwise be unable to access OIT.

Update of the S2k guideline on the management of IgE-mediated food allergies

Not available.

Food Allergy from Infancy Through Adulthood

Food allergies are the result of immune responses that cause adverse reactions to foods. Immune responses to foods may produce a spectrum of symptoms and disorders, including acute allergic reactions and anaphylaxis, food protein-induced allergic proctocolitis, food protein-induced enterocolitis syndrome, food-dependent, exercise-induced anaphylaxis, and oral allergy syndrome (pollen-food allergy syndrome). Food-allergic responses also contribute to chronic inflammatory disorders such as eosinophilic esophagitis and atopic dermatitis. Although food allergy affects people from infancy through adulthood, there are allergic features that differ according to age (ie, presentation, triggers, and natural course) and have important implications for diagnosis, prognosis, and management. New food allergies can develop at any age, and we propose similarities in the etiology of de novo food allergy whether in infancy or adulthood. The approach to managing food allergy changes dramatically over the life course, and physicians and patients must respond accordingly to optimize care. Food allergy therapies are emerging, and the efficacy and safety of these interventions could differ by age group of those treated. In this review, we highlight interesting observations on the etiology and characteristics of food allergy presenting at different ages and discuss clinical management as it relates to life stage.

Are avoidance diets still warranted in children with atopic dermatitis?

Nearly 40% of children with moderate-to-severe atopic dermatitis (AD) have IgE-mediated food allergy (FA). This clinical observation has been extensively documented by experimental data linking skin inflammation in AD to FA, as well as by food challenges reproducing symptoms and avoidance diets improving AD. Although food avoidance may improve AD, avoidance diets do not cure AD, may even have detrimental effects such as progression to immediate-type allergy including anaphylactic reactions, and may significantly reduce the quality of life of the patient and the family. AD care should focus upon optimal medical management, rather than dietary elimination. Food allergy testing is primarily indicated when immediate-type allergic reactions are a concern. In recalcitrant AD, if food is being considered a possible chronic trigger, a limited panel of foods may be tested. An avoidance diet is only indicated in patients clearly identified as food allergic by an appropriate diagnostic food challenge, and after adequately informing the family of the limited benefits, and possible harms of an elimination diet.

Conservation Analysis of B-Cell Allergen Epitopes to Predict Clinical Cross-Reactivity Between Shellfish and Inhalant Invertebrate Allergens

Understanding and predicting an individual's clinical cross-reactivity to related allergens is a key to better management, treatment and progression of novel therapeutics for food allergy. In food allergy, clinical cross-reactivity is observed in patients reacting to unexpected allergen sources containing the same allergenic protein or antibody binding patches (epitopes), often resulting in severe allergic reactions. Shellfish allergy affects up to 2% of the world population and persists for life in most patients. The diagnosis of shellfish allergy is however often challenging due to reported clinical cross-reactivity to other invertebrates including mites and cockroaches. Prediction of cross-reactivity can be achieved utilizing an in-depth analysis of a few selected IgE-antibody binding epitopes. We combined available experimentally proven IgE-binding epitopes with informatics-based cross-reactivity prediction modeling to assist in the identification of clinical cross-reactive biomarkers on shellfish allergens. This knowledge can be translated into prevention and treatment of allergic diseases. To overcome the problem of predicting IgE cross-reactivity of shellfish allergens we developed an epitope conservation model using IgE binding epitopes available in the Immune Epitope Database and Analysis Resource (http://www.iedb.org/). We applied this method to a set of four different shrimp allergens, and successfully identified several non-cross-reactive as well as cross-reactive epitopes, which have been experimentally established to cross-react. Based on these findings we suggest that this method can be used for advanced component-resolved-diagnosis to identify patients sensitized to a specific shellfish group and distinguish from patients with extensive cross-reactivity to ingested and inhaled allergens from invertebrate sources.

Food allergy to previously tolerated foods: Course and patient characteristics

BACKGROUND

The acquisition of food allergy (FA) to previously safely consumed basic food proteins is an unusual presentation of immunoglobulin E (IgE)-mediated allergic disease.

OBJECTIVE

We sought to characterize patients who developed FA to previously tolerated foods (FA-PTF), including underlying reasons for and length of elimination diet of previously tolerated foods.

METHODS

Patients (n = 30) with complaints consistent with FA to foods previously consumed safely were evaluated. Clinical history was obtained, and skin prick testing and graded oral food challenges (OFC) were performed. One fatal case of FA-PTF was reported by a physician.

RESULTS

Twenty-two of 30 patients (ages 1.2-50 years) were diagnosed with FA-PTF by OFC to milk (n = 17), egg (n = 2), and peanuts (n = 3). One additional patient with FA-PTF had a fatal reaction to milk. Anaphylactic reactions were reported in 12 of these 23 FA-PT patients (52%); 8 experienced multiple episodes. Atopic dermatitis was diagnosed in 52% (12/23) of patients, 8 of 12 as severe; overall, 18 of 23 (78%) of patients had marked personal atopic background. Sixteen patients (70%) initiated an elimination diet, 12 of whom did so on advice from a health care provider, before the appearance of allergic symptoms. However, in 4 patients with FA-PTF, reactivity to the food protein emerged during uninterrupted consumption.

CONCLUSION

Food allergy to previously tolerated foods primarily appears after an elimination diet in atopic patients. Anaphylactic reactions are common. Health care providers should consider these risks before recommending elimination diet of tolerated foods.

Dietary Therapy and Nutrition Management of Eosinophilic Esophagitis: A Work Group Report of the American Academy of Allergy, Asthma, and Immunology

Eosinophilic esophagitis (EoE) is a chronic/immune-antigen-mediated disease characterized clinically by symptoms related to esophageal dysfunction and histologically by eosinophil-predominant inflammation. Dietary elimination therapy has been shown to be an effective, drug-free prescription for the treatment of EoE. A range of different dietary elimination therapies have been used. Regardless of the elimination diet chosen, dietary therapy requires in-depth nutrition assessment and management. Elimination diets are not without risk and may impact nutritional status, eating pleasure, and overall quality of life. With adequate guidance, dietary therapy can be effective and nutritionally balanced, and the adverse impact on lifestyle can be minimized. This work group report addresses the potential challenges of implementing an elimination diet for the management of EoE and provides instructions and tools for physicians, dietitians, and other allied health professionals to help guide them in planning elimination diets for both children and adults.

IgE-mediated food allergy in children

Food allergy is a serious health issue affecting roughly 4% of children, with a substantial effect on quality of life. Prognosis is good for the most frequent allergens with almost all children outgrowing their allergy. However, the long-term implications for disease burden are substantial for children with persistent allergies (eg, peanuts, tree nuts, fish, and shellfish) and for those with high concentrations of milk, egg, and wheat IgE. Antigen avoidance has been the time-honoured approach both for prevention and treatment. However, findings from studies done in the past 5 years show that early contact with food can induce tolerance and desensitisation to foods. We review the epidemiology, natural history, and management of food allergy, and discuss the areas of controversy and future directions in research and clinical practice.

Food avoidance in children with adverse food reactions: influence of anxiety and clinical parameters

BACKGROUND

Many children in the general population avoid food because of self-reported adverse food reactions (AFR). Food avoidance can have negative consequences for well-being and nutritional status. This study aimed to investigate which factors are related to avoidance behavior in children (10-13 yr old) from the general population.

METHODS

Questionnaires for both mother and child were sent to participants from the Europrevall study: 164 children with self-reported AFR and 170 children without AFRs. Spielberger state anxiety and trait anxiety and clinical parameters, such as severity of the adverse reaction, specific IgE and doctor's diagnosis, were compared between those who have (had) AFR and avoid food (i.e., avoiders) and those who have (had) AFR(s) and do not avoid food (anymore; i.e., non-avoiders).

RESULTS

In total, 59% of the children with AFRs avoided food, of whom 26% had positive specific immunoglobulin E (sIgE). Child's state anxiety about an AFR was higher in avoiders than in non-avoiders, (p < 0.001), whereas child's trait anxiety and maternal state anxiety and trait anxiety were comparable in both groups. Avoiders reported more often severe symptoms (i.e., generalized urticaria, respiratory or cardiovascular symptoms) than non-avoiders, (p = 0.03). Food avoidance was not associated with doctor's diagnosis of food allergy or doctor's advice to avoid food (p = 1.00).

CONCLUSION

Food avoidance is related to child's state anxiety about an adverse food reaction. Food avoidance seems to be independent of a doctor's diagnosis of food allergy and advice on food avoidance.

Sesame seed food allergy

The number of reports regarding sesame seed food allergy (SFA) has increased significantly worldwide over the past two decades, either due to a genuine increase in SFA or merely an increase in its awareness. Its prevalence is difficult to estimate due to the lack of well designed prospective population-based studies. Based on the available data, we estimate that SFA affects 0.1-0.2 % of the population, in areas where the food is available. Albeit this prevalence appears to be relatively low, it is approximately one-half of that of persistent cow's milk allergy. While only one fatality has been reported, the significant number of SFA patients presenting as anaphylaxis indicates the potential risk. Many reports based the diagnosis of SFA on sensitization criteria alone, particularly amongst atopic dermatitis patients. Elimination of sesame from the diet of these children utilizing such criteria is not justified, and may even increase the risk for developing SFA.

Allergenicity of casein containing chalk in milk allergic schoolchildren

BACKGROUND

Nondietary exposure to milk proteins may be a risk for children who do not outgrow milk allergy by school age.

OBJECTIVE

To study the allergenicity of casein containing chalk.

METHODS

A 6-year-old, milk allergic child developed asthma and rhinoconjunctivitis while in school. The suspected cause was dust-free chalk containing casein. To study the relationship of dust-free chalk containing casein with asthma and rhinoconjunctivitis, 13 additional milk allergic patients were studied: 3 school-aged children, 8 preschool-aged infants, and 2 children with outgrown milk allergy. Skin tests and/or specific IgE with chalk and casein were performed. A chalk use test was performed in older children. Milk allergens contained in chalk were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblot, and IgE inhibition experiments.

RESULTS

All school-aged, milk allergic children were exposed to chalk and reported symptoms attributed to chalk exposure. The skin test result to chalk was positive in 5 of 12 cases, and the specific IgE test result was positive in all 12 study participants in which it was performed. Casein strongly inhibited the binding of IgE to chalk. Chalk sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed proteins with molecular weight similar to caseins. Immunoblot demonstrated strong binding of IgE to chalk in a blurred pattern and a band at 30 kDa, inhibited by casein. The chalk challenge test result was positive in 2 school-age children who had a positive skin test result to chalk. Their symptoms improved after avoidance of chalk in the school. In 2 other cases in which the challenge test result was negative, chalk was reintroduced without problems.

CONCLUSION

Inhalation of chalk dust containing casein can induce asthma symptoms in milk allergic patients. Hidden and nondietary sources of exposure should always be considered in food allergic patients.

Dietary baked egg accelerates resolution of egg allergy in children

BACKGROUND

Baked egg is tolerated by a majority of egg-allergic children.

OBJECTIVE

To characterize immunologic changes associated with ingestion of baked egg and evaluate the role that baked egg diets play in the development of tolerance to regular egg.

METHODS

Egg-allergic subjects who tolerated baked egg challenge incorporated baked egg into their diet. Immunologic parameters were measured at follow-up visits. A comparison group strictly avoiding egg was used to evaluate the natural history of the development of tolerance.

RESULTS

Of the 79 subjects in the intent-to-treat group followed for a median of 37.8 months, 89% now tolerate baked egg and 53% now tolerate regular egg. Of 23 initially baked egg-reactive subjects, 14 (61%) subsequently tolerated baked egg and 6 (26%) now tolerate regular egg. Within the initially baked egg-reactive group, subjects with persistent reactivity to baked egg had higher median baseline egg white (EW)-specific IgE levels (13.5 kU(A)/L) than those who subsequently tolerated baked egg (4.4 kU(A)/L; P= .04) and regular egg (3.1 kU(A)/L; P= .05). In subjects ingesting baked egg, EW-induced skin prick test wheal diameter and EW-, ovalbumin-, and ovomucoid-specific IgE levels decreased significantly, while ovalbumin- and ovomucoid-specific IgG(4) levels increased significantly. Subjects in the per-protocol group were 14.6 times more likely than subjects in the comparison group (P< .0001) to develop regular egg tolerance, and they developed tolerance earlier (median 50.0 vs 78.7 months; P< .0001).

CONCLUSION

Initiation of a baked egg diet accelerates the development of regular egg tolerance compared with strict avoidance. Higher serum EW-specific IgE level is associated with persistent baked and regular egg reactivity, while initial baked egg reactivity is not.

Food allergy: is strict avoidance the only answer?

It is an immunological paradigm that avoidance of food allergen may reduce the risk or prevent immunological reactions and conversely that a greater exposure increases the magnitude of the immune response. Consequently, food allergen avoidance has been recommended to reduce the risk of sensitization in infants and to prevent clinical reactions in children with positive skin prick tests (SPT). In the latter setting, it is hoped that avoidance may either promote or at least not retard the development of tolerance. Animal studies, however, have demonstrated that tolerance to food allergens may be induced by either large (high zone tolerance) or small (low zone tolerance) doses, whereas doses in between may actually stimulate immune responses. In this review, we discuss whether strict allergen avoidance is always the most appropriate strategy for preventing or managing IgE-mediated food allergy.

Cow's milk protein allergy. A multi-centre study: clinical and epidemiological aspects

BACKGROUND

Due to the age when it becomes apparent and the treatment needed, cow's milk proteins (CMP) allergy requires an accurate diagnosis to avoid labelling infants falsely as allergic and subjecting them to unnecessary diets. The objective of this multi-centre study carried out at the Allergy Units of 14 Children's Hospitals was to discover the epidemiological, clinical and evolutionary characteristics of cow's milk protein allergy (CMPA).

METHODS AND RESULTS

Infants suspected of CMPA who attended allergy clinics at the hospitals taking part during the study period were studied and a detailed clinical history was collected on all of them. Prick tests were done with cow's milk and its proteins and specific IgE anti-bodies were determined by means of CAP with the same allergens as the Prick test. The challenge test with cow's milk was carried out unless contraindicated by the diagnostic protocol. Two different challenge regimens were used: one of them carried out in 3 days and the other in one day. 409 infants with suspected CMPA were included and the diagnostic challenge test was performed on 286 patients (70 %) and not carried out on 123, as it was not indicated according to the protocol. IgE-mediated allergy was confirmed in 234 infants (58 %) and in 15 (4 %) non-IgE-mediated hypersensitivity was diagnosed. The two challenge regimens were equally secure. The average age when the reaction to cow's milk formula took place was 3.5 months (10 days-10 months). The symptoms appeared in the first week of introduction in 95 % of cases and appeared in 60 % with the first feeding with the formula. The most frequent clinical signs were cutaneous in 94 % of cases and the majority of cases appeared within 30 minutes of the feed. 99 % had been breast fed and 44 % had received some cow's milk supplement during the lactation period. Sensitization to egg not given in the feed was noted in 30 % and to beef in 29 %, being well tolerated in all of these.

CONCLUSIONS

Carrying out an appropriate diagnostic protocol in infants attending for suspected CMPA allows allergy to be ruled out in a high percentage of cases.

Acute allergic reactions in children with AEDS after prolonged cow's milk elimination diets

BACKGROUND

Food allergy is not always correctly diagnosed in children with atopic eczema dermatitis syndrome (AEDS) and treatment with an avoidance diet is not without danger.

METHODS

After admission to our clinic, 11 children with a prolonged cow's milk (CM) elimination diet because of AEDS and sensitization underwent double-blind placebo-controlled food challenge (DBPCFC). Retrospectively, the exposure to CM, sensitization and reactions to accidental ingestion were carefully documented. The DBPCFC was used to evaluate the childrens' current status.

RESULTS

Before the elimination period (median 2.3 years; started before the admission) all 11 children with AEDS were sensitized and had ingested CM (four bottle-fed; seven breast-fed without CM diet of the mother) without the development of acute reactions. The diagnosis of CM allergy was not confirmed by DBPCFC previously. After elimination the AEDS had not improved, but nevertheless the diet was continued. During the elimination period, eight of 11 children developed severe acute allergic reactions to CM after accidental ingestion. In evaluation, in our clinic all 11 children experienced acute allergic reactions to CM during DBPCFC.

CONCLUSION

There is a considerable chance of developing acute allergic reactions to CM after elimination in children with AEDS without previous problems after CM intake.

Food allergy diagnosis: are there any missing factors? A theoretical approach

Actual diagnostic criteria in food allergy frequently show a group of subjects with uncertain diagnosis, i.e., subjects with only occasional reactions to an offending food. These subjects are probably under- or misdiagnosed. It is possible that food itself may be only one of the factors involved in the allergic food reaction, at least in these subjects. In these cases, several factors besides food could modify either the allergenic potential of food or the absorption of allergens and may be relevant for a clinical response to occur. In order to investigate the possible relevance of missing factors, a theoretical model is elaborated by modifying the equation that represents the classical food allergy model: xAg+(IgE(*)-cell)--> clinical response (mediators release em leader ). In this classical model, it is assumed that if there is specific IgE against a food (IgE*-cell), the only limiting factor will be x (total amount of allergen ingested), being Ag, the allergen supposed to elicit a clinically relevant response. Always that x>/=a (threshold quantity of allergen that elicits a reaction) a reaction should occur. The possible existence of missing factors, i.e., the presence of 'modified allergens' (Ag('),Ag("), em leader,Ag(n)) induced by modification of the allergenic potential of food, are not considered in the equation, but these factors may have clinical relevance, and these relevance could be related to x(1),x(2), em leader,x(n) (relative quantities of 'modified allergens'). So, a modified formula is proposed:(x-Sigma(x(1),x(2), . . . x(n)]Ag+Sigma(x(1)Ag('),x(1)Ag("), . . . x(n)Ag(n)]+IgE(*)-cell)-->clinical response. In this formula, depending of the relative amount of the limiting factors: x(1),x(2), . . . x(n) and the relevant allergen (Ag,Ag('),Ag(") . . . or Ag(n)) to which the subject is sensitized an allergic reaction could or could not be elicited. So, factors other that the food itself and the threshold of sensitivity may be missed in the diagnosis of food allergy. When there are not any factors modifying Ag, the allergic response will depend only on the amount of x ('classical equation'). But when there is some kind of modification the response will depend on the relevance of the modified allergens and on the relative amount of them. If the factors modifying the allergenicity cannot be controlled, the amount of the clinically relevant allergen cannot be estimated, and the clinical response may be only occasional, explaining the inconsistent findings of some subjects.

Fish allergy: is cross-reactivity among fish species relevant? Double-blind placebo-controlled food challenge studies of fish allergic adults

BACKGROUND

Allergic reactions to fish are a common cause of food allergy in many areas of the world where fish is a major source of protein. Although different species of fish may be consumed, possible cross-reactivity has received limited investigation.

OBJECTIVE

The aim of this study was to assess potential cross-reactivity to different species of fish species using double-blind, placebo-controlled food challenges (DBPCFC) in fish-allergic adults and to compare skin test and RAST reactivity with the challenge response.

METHODS

Nine skin prick test and/or RAST-positive adult individuals with histories of an immediate-type reaction following fish ingestion were challenged with different fish species using double-blind, placebo-controlled food challenge.

RESULTS

Of a total of 19 double-blind, placebo-controlled fish challenges performed, 14 challenges (74%) resulted in the induction of objective signs that were consistent with an IgE-mediated response. The most common sign observed was emesis (37%); the most prevalent subjective symptoms reported were compatible with the oral allergy syndrome (84%). Three subjects reacted to at least three fish species and one subject reacted to two fish species tested. In regard to the positive challenges, predictive accuracy of skin prick test and RAST was 84% and 78%, respectively.

CONCLUSION

Our results indicate that clinically relevant cross-reactivity among various species of fish may exist. Advising fish-allergic subjects to avoid all fish species should be emphasized until a species can be proven safe to eat by provocative challenge.

Benefits and risks of elimination diets

Elimination diets have been used for the prevention or treatment of allergic disease with the diet of the pregnant or breastfeeding mother or the child, or both, being modulated as deemed appropriate. Evidence from studies published so far suggests that dietary restrictions are in fact effective only in the treatment of specific food allergies, not in allergy prevention. An elimination diet of a child or a breastfeeding mother entails a risk to normal nutrition and growth of the child. Although studies are lacking, dietary restrictions during lactation may well be harmful also to the mother's health. Substitution of nutritionally important foods and professional guidance are necessary for the successful treatment of food allergies.

Allergy to lentils in Mediterranean pediatric patients

BACKGROUND

Peanuts and soybeans are the major legumes involved in human food allergy; however, scarce data exist on adverse reactions to other temperate legumes, such as lentils.

OBJECTIVE

The purpose of this study was to identify patients who are allergic to lentils, to assess clinical features and other associated food allergies, and to characterize allergens in lentil extract.

METHODS

Twenty-two children each with a history of adverse reactions to lentils were enrolled in the study. The diagnosis of lentil allergy was based on food challenges or a convincing history of anaphylaxis, with positive skin tests and/or specific serum IgE to lentils. Lentil components were characterized by SDS-PAGE immunoblotting.

RESULTS

Twenty of 22 subjects had symptomatic allergy to lentils at the diagnostic time. The most frequent symptoms were oropharyngeal symptoms (40%) and acute urticaria (30%); 3 patients also reported symptoms when they were exposed to steam from cooked lentils. In 18 patients, symptoms after lentil ingestion started under 4 years of age (median, 2.7 years). Nine patients had allergic reactions to other legumes: chick peas (6 patients), peas (2 patients), and green beans (1 patient). Immunoblotting patterns obtained with patients' sera showed IgE-binding bands ranging from 14 to 84 kd. Five sera recognized 9 or more IgE-binding bands, and more than 50% of patients who were tested have specific IgE antibodies to 7 components in lentil extract.

CONCLUSION

Allergic reactions to lentils started early in life, usually below 4 years of age; oropharyngeal symptoms and acute urticaria were the most common symptoms through ingestion, and symptomatic reactivity to chick peas is frequently associated.

Allergic reactions associated with airborne fish particles in IgE-mediated fish hypersensitive patients

We evaluated the clinical characteristics found in 21 children who showed allergic reactions upon incidental inhalation of fish odors or fumes, from 197 diagnosed with IgE-mediated fish hypersensitivity. Allergic reactions to fish via ingestion began in most patients (86%) within the first 24 months of life. The vast majority (19/21) of patients showed cutaneous symptoms, either alone or, less frequently, associated with other clinical manifestations. Hake and flounder were the species of fish most frequently implicated in eliciting clinical manifestations upon ingestion. After diagnosis, all these patients were placed on a strict fish-avoidance diet. During this period of avoidance, patients reported allergic reactions (mean age 7 years) after incidental exposure to airborne fish odors or fumes. Clinical manifestations through inhalation were respiratory (mainly wheezing) in 12 patients and cutaneous (mainly urticaria) in nine patients. Nineteen of 21 patients reported three or more episodes upon exposure to fish aerosols; in most cases, these episodes occurred at home when other people were eating fish. In conclusion, incidental inhalation of fish odors or fumes could play an important role in accidental and unknown encounters with fish in children on fish-avoidance diets for fish IgE-mediated hypersensitivity. Such exposures could elicit clinical symptoms and could have some effect in delaying the development of tolerance.

Frequency of food allergy in a pediatric population from Spain

We evaluated the prevalence and characteristics of the principal foods implicated in 355 children diagnosed with IgE-mediated food allergy. Diagnosis was established on the basis of positive clinical history for the offending food, positive specific IgE by skin prick test and RAST, and open food challenge. Our results showed the principal foods involved in allergic reactions are: eggs, fish, and cow's milk. These are followed in frequency by fruits (peaches, hazelnuts and walnuts), legumes (lentils, peanuts and chick peas) and other vegetables (mainly sunflower seeds). The legumes demonstrated the highest degree of clinical cross-reactivity. Most patients with food allergy reacted to one or two foods (86.7%). Only 13.3% of patients reacted to 3 or more foods, mostly to legumes and fruits. We found that food allergy begins most frequently in the first (48.8%) and second (20.4%) years of life. Allergy to proteins of cow's milk, egg, and fish begins predominantly before the second year, demonstrating a clear relationship with the introduction of these foods into the child's diet. Allergy to foods of vegetable origin (fruits, legumes and other vegetables) begins predominantly after the second year.