Controversial aspects of adverse reactions to food. European Academy of Allergology and Clinical Immunology (EAACI) Reactions to Food Subcommittee

A comparison of double-blind, placebo-controlled food challenge and open food challenge

BACKGROUND

Double-blind, placebo-controlled food challenge (DBPCFC) remains the gold standard for diagnosing food allergy, despite sparse comparisons to open food challenges (OpenFCs). The objective of this retrospective study was to compare severity of symptoms and threshold values (cumulative dose of food allergen eliciting a clinical reaction) in children and adults with peanut allergy, challenged in an open and/or double-blind, placebo-controlled protocol.

METHODS

This study included patients from the Allergy Centre, Odense University Hospital with a positive oral food challenge, defined as strict objective signs, with peanut during the period 2001-2022. Severity of symptoms was graded using the Sampson's severity score. Distribution models of threshold values were calculated using log-normal interval-censored survival analysis, and the number of placebo reactions was evaluated.

RESULTS

In total, 318 positive OpenFCs and 86 DBPCFCs were included. There was no difference in severity of symptoms nor threshold values comparing the two challenge types, neither when stratified for age groups. However, a higher proportion of children experienced Grade 3 symptoms in the double-blind group. Only one patient had a positive reaction to a placebo challenge.

CONCLUSION

Our findings do not advocate for DBPCFC being superior to OpenFC, if the latter is performed with strict objective stop criteria by trained staff.

Laboratory tests commonly used in complementary and alternative medicine: a review of the evidence

It is increasingly easy for the general public to access a wide range of laboratory tests. Tests can be ordered online with little or no input from a health professional. The complementary and alternative medicine (CAM) community promote and sell a wide range of tests, many of which are of dubious clinical significance. Many have little or no clinical utility and have been widely discredited, whilst others are established tests that are used for unvalidated purposes. They range from the highly complex, employing state of the art technology, e.g. heavy metal analysis using inductively coupled plasma-mass spectrometry, to the rudimentary, e.g. live blood cell analysis. Results of 'CAM tests' are often accompanied by extensive clinical interpretations which may recommend, or be used to justify, unnecessary or harmful treatments. There are now a small number of laboratories across the globe that specialize in CAM testing. Some CAM laboratories operate completely outside of any accreditation programme whilst others are fully accredited to the standard of established clinical laboratories. In this review, we explore CAM testing in the United States, the United Kingdom and Australia with a focus on the common tests on offer, how they are reported, the evidence base for their clinical application and the regulations governing their use. We will also review proposed changed to in-vitro diagnostic device regulations and how these might impact on CAM testing.

Estimate of the theoretical maximum daily intake of Sunset Yellow FCF by the Brazilian population

This study estimated the theoretical maximum daily intake (TMDI) of Sunset Yellow (SY) synthetic food dye by the Brazilian population through food consumption data from the Household Budget Survey (HBS) of the Brazilian Institute of Geography and Statistics (IBGE, 2008/09). The study covered the population in urban and rural areas in the five regions of the country, and from different age groups, in order to verify if it were possible to exceed the acceptable daily intake (ADI) of SY, which is 4.0 mg kg^-1 body weight. This was assessed by cross-checking food products containing this dye from the largest supermarket chains in Brazil with data from the HBS-IBGE 2008/09. These data showed that the average consumption of SY per capita did not exceed the ADI in any of the aforementioned population groups. However, when considering food consumption in urban and rural areas (279 and 260 mg of SY day^-1), in the five regions of the country (260-338 mg of SY day^-1), and for adolescents (332 mg SY day^-1), it is noted that part of the population could be exceeding the recommended ADI, which may pose health risks. Although it is unlikely that individuals will exceed the SY ADI, this may occur in some cases, especially for younger people.

[Food allergy in adulthood]

Food allergies can newly arise in adulthood or persist following a food allergy occurring in childhood. The prevalence of primary food allergy is basically higher in children than in adults; however, in the routine practice food allergies in adulthood appear to be increasing and after all a prevalence in Germany of 3.7 % has been published. The clinical spectrum of manifestations of food allergies in adulthood is broad. Allergy symptoms of the immediate type can be observed as well as symptoms occurring after a delay, such as indigestion, triggering of hematogenous contact eczema or flares of atopic dermatitis. The same principles for diagnostics apply in this group as in childhood. In addition to the anamnesis, skin tests and in vitro tests, as a rule elimination diets and in particular provocation tests are employed. Molecular allergy diagnostics represent a major step forward, which allow a better assessment of the risk of systemic reactions to certain foodstuffs (e.g. peanuts) and detection of cross-reactions in cases of apparently multiple sensitivities. Current German and European guidelines from 2015 are available for the practical approach to clarification of food allergies. The most frequent food allergies in adults are nuts, fruit and vegetables, which can cross-react with pollen as well as wheat, shellfish and crustaceans. The therapy of allergies involves a consistent avoidance of the allogen. Detailed dietary plans are available with avoidance strategies and instructions for suitable food substitutes. A detailed counseling of affected patients by specially trained personnel is necessary especially in order to avoid nutritional deficiencies and to enable patients to enjoy a good quality of life.

Diagnostic and Therapeutic Iter in Chronic Urticaria Patients

We describe a diagnostic and therapeutic protocol for the management of chronic urticaria. It is derived from an extensive review of current literature, with a cost-effective evaluation of laboratory investigations and therapeutic approaches. Our protocol may not represent a cornerstone for chronic urticaria: much has in fact to be clarified on pathogenetic mechanisms and aetiological factors. Nevertheless, its application should be able, in our opinion, to identify what is useful or not in the everyday management of chronic urticaria patients.

Food allergy and related risk factors in 2540 preschool children: an epidemiological survey in Guangdong Province, southern China

BACKGROUND

Although the number of studies on allergic diseases in the general population of southern China is increasing, only a few have addressed food allergy (FA) in children in this region. The present study aimed to investigate the prevalence, clinical manifestations, spectrum of allergens, and related risk factors of FA in preschool children in Guangdong Province, southern China.

METHODS

A random cluster-sampling method was used to select 24 kindergartens from 12 cities in Guangdong Province. The parents or guardians of the children were requested to complete a questionnaire on general information and data regarding FA diagnosis and symptoms in the children and their first-degree relatives. Thereafter, the Chi-square test, multivariate regression analysis, and Spearman's rank-order correlation coefficient analysis were performed to identify statistically significant differences.

RESULTS

Analysis of 2540 valid questionnaires revealed an FA prevalence rate of 4%. Adverse food reactions were due to the consumption of shrimp (4.4%), crab (3.2%), mango (2.3%), cow's milk and dairy products (1.9%), and eggs (1.4%). Logistic regression analysis indicated that a history of FA and a history of allergic rhinitis in the first-degree relatives were the major factors leading to FA in children.

CONCLUSIONS

The incidence of FA in children in Guangdong Province is higher than that commonly believed. An individual's genetic background is an important risk factor for FA. Hence, mitigation of the impact of lifestyle and environmental factors should be carefully considered to reduce the incidence of childhood FA.

Juvenile allergic urethritis with urethro-ejaculatory reflux presenting as acute intermittent bilateral testicular torsion

We report a case of juvenile allergic urethritis secondary to double concentrate orange squash of a famous brand in a 3-year-old boy who developed bilateral urethro-ejaculatory reflux (UER) and severe urethral, perineal and scrotal pain referred to both lower limbs intermittently predominantly during and after micturition-simulating features of bilateral intermittent testicular torsion. Accurate history, urinalysis, ultrasound, colour Doppler and food challenge were helpful in diagnosis. Topical steroids, antihistaminic, analgesic and anti-inflammatory medications together with withdrawal of the allergen produced complete recovery. Allergic urethritis in association with bilateral UER causing secondary seminal vesiculitis and epididymitis is rare. It presented as acute scrotum and responded to innovative treatment. Allergic disease can have a dramatic effect on a child's quality of life. This is the first documented case of allergic urethritis and associated UER presenting as juvenile acute scrotum. Steroids, antihistamines and anti-inflammatory agents together with avoidance of the allergen helped achieve recovery.

Food allergy in irritable bowel syndrome: The case of non-celiac wheat sensitivity

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders, having a prevalence of 12%-30% in the general population. Most patients with IBS attribute their symptoms to adverse food reactions. We review the role of diet in the pathogenesis of IBS and the importance of dietary factors in the management of these patients. The MEDLINE electronic database (1966 to Jan 2015) was searched using the following keywords: "food", "diet", "food allergy", "food hypersensitivity", "food intolerance", "IBS", "epidemiology", "pathogenesis", "pathophysiology", "diagnosis", "treatment". We found 153 eligible papers; 80 were excluded because: not written in English, exclusive biochemical and experimental research, case reports, reviews, and research otherwise not relevant to our specific interest. We selected 73 papers: 43 original papers, 26 reviews and 4 letters to the editor. These papers focused on IBS pathogenesis, the association between IBS and atopy, and between IBS and food allergy, the relationship between IBS and non-celiac wheat sensitivity, the role of diet in IBS. Pending further scientific evidence, a cautious approach is advisable but the concept of food allergy should be included as a possible cause of IBS, and a dietary approach may have a place in the routine clinical management of IBS.

Interaction between ingested nutrients and gut endocrine cells in patients with irritable bowel syndrome (review)

Several endocrine cell abnormalities have been reported in different segments of the gastrointestinal tract of patients with irritable bowel syndrome (IBS). These cells have specialized microvilli that project into the lumen; they function as sensors for the gut contents and respond to luminal stimuli (mostly ingested nutrients) by releasing hormones into the lamina propria, where they exert their effects via a paracrine/endocrine mode of action. Certain food items trigger the symptoms experienced by IBS patients, including those rich in fermentable oligo-, di- and monosaccharides, and polyols (FODMAPs). In this review, we present the argument that the effects of both FODMAPs and the proportional intake of proteins, fats and carbohydrates on IBS symptoms may be caused by an interaction with the gut endocrine cells. Since the gut hormones control and regulate gastrointestinal motility and sensation, this interaction may be responsible for abnormal gastrointestinal motility and the visceral hypersensitivity observed in these patients. There is no consistent evidence that IBS patients suffer from food allergy. The role of gluten intolerance in the development of IBS symptoms in these patients remains a matter of controversy. Individual guidance on food management, which includes restrictions in the intake of FODMAP-rich foods and testing diets with different proportions of proteins, fats and carbohydrates has been found to reduce the symptoms, improve the quality of life, and make the habitual diet of IBS patients more healthy.

Group 10 allergens (tropomyosins) from house-dust mites may cause covariation of sensitization to allergens from other invertebrates

Group 10 allergens (tropomyosins) have been assumed to be a major cause of cross-reactivity between house-dust mites (HDMs) and other invertebrates. Despite all of the published data regarding the epidemiology, percent IgE binding and level of sensitization in the population, the role of tropomyosin as a cross-reactive allergen in patients with multiple allergy syndrome still remains to be elucidated. Homology between amino acid sequences reported in allergen databases of selected invertebrate tropomyosins was determined with Der f 10 as the reference allergen. The 66.9 and 54.4% identities were found with selected crustacean and insect species, respectively, whereas only 20.4% identity was seen with mollusks. A similar analysis was performed using reported B-cell IgE-binding epitopes from Met e1 (shrimp allergen) and Bla g7 (cockroach allergen) with other invertebrate tropomyosins. The percent identity in linear sequences was higher than 35% in mites, crustaceans, and cockroaches. The polar and hydrophobic regions in these groups were highly conserved. These findings suggest that tropomyosin may be a major cause of covariation of sensitization between HDMs, crustaceans, and some species of insects and mollusks.

Intolerance to food additives - does it exist?

'Food intolerance' is often confused with a range of adverse symptoms which may be coincidental to ingestion of food. 'Food intolerance' is defined as a reaction in which symptoms must be objectively reproducible and not known to involve an immunological mechanism. A more precise term is non-allergic food hypersensitivity, which contrasts with food allergies which are due to an immunological mechanism. Some children will experience food reactions to food additives. Reported symptoms range from urticaria/angioedema to hyperactive behaviours. While parents/carers report that over one fifth of children experience of food reaction, only 1 in 20 of these are confirmed to have a non-allergic food hypersensitivity on testing.

Molecular diagnosis of cow's milk allergy

PURPOSE OF REVIEW

To identify and discuss studies on the molecular diagnosis of cow's milk allergy (CMA) with a view to update allergists since a general review of the methodology in 2006.

RECENT FINDINGS

Seven basic research studies reporting the use of component-resolved diagnostics in CMA were found. All studies were on children positively reacting to a formal challenge with cow's milk. Six studies used natural allergens and three used recombinant milk proteins. Microarray platforms were customized and, thus, differed across studies. Three studies assessed the association between molecular-scale patterns and different presentations of the condition, that is the association between anaphylaxis, gastrointestinal symptoms and other severe phenotypes and the pattern of protein sensitization. Two studies assessed the association between positive oral food challenge and the persistence of milk allergy over time. Protein profiling could be useful to indicate appropriate specific immunotherapy.

SUMMARY

Accurate diagnosis of CMA is challenging and essential. The determination of the immunoglobulin E (IgE)-mediated response to sequenced and characterized allergens may be more useful in predicting the presence and severity of clinical allergy than the currently used skin or blood tests performed with whole extracts. However, as component recognition pattern heterogeneity is observed in different areas, further clinical studies are essential to correlate useful molecular diagnostics and biological markers with disease and patient profiles. Until such markers are found and validated in different age groups, oral food challenge remains the reference standard for the diagnosis of CMA.

Self-reported food intolerance and mucosal reactivity after rectal food protein challenge in patients with rheumatoid arthritis

OBJECTIVES

A dietary link to rheumatoid arthritis (RA) has been suspected and an influence on arthritic symptoms by different diets has been reported. Our primary aim was to record the self-experienced adverse food reactions in patients with RA. A secondary aim was to relate self-experienced adverse reactions to dairy produce and wheat to the local mucosal reactivity observed after rectal challenge with cow's milk protein (CM) and wheat gluten.

METHODS

A questionnaire about self-experienced adverse reaction to food was sent to 347 RA patients. Rectal challenge with CM and gluten was performed in 27 of these patients and in healthy controls (n = 18). After a 15-h challenge the mucosal production of nitric oxide (NO) and the mucosal release of myeloperoxidase (MPO) and eosinophil cationic protein (ECP) were measured by using the mucosal patch technique.

RESULTS

Twenty-seven per cent of the RA patients reported food intolerance (FI) to various foods, and in particular to CM, meat, and wheat gluten. Strong mucosal reactivity to CM was observed in 11% of the patients. Moderately increased mucosal reactivity to CM and gluten was found in 22% and 33%, respectively, of the patients. No relationship was found between self-experienced adverse reactions to CM or gluten and mucosal reactivity to these proteins.

CONCLUSIONS

Perceived FI is reported frequently by RA patients, with a prevalence similar to that reported previously in the general population. Mucosal reactivity to CM and gluten is seen in a minor fraction of RA patients and is not related to the frequently perceived intolerance to these proteins.

Are excipients really inert ingredients? A review of adverse reactions to excipients in oral dermatologic medications in Canada

BACKGROUND

Whereas several literature reviews have discussed the role of excipients in drug-related reactions, no article has focused specifically on those found in oral dermatologic medications.

METHODS

The Compendium of Pharmaceuticals and Specialties (CPS) was used to reference the inert ingredients found in oral dermatologic medications. An extensive literature review was subsequently conducted using PubMed and MEDLINE to document adverse reactions to these excipients.

RESULTS

Sixty-three oral dermatologic medications were reviewed. Lactose was commonly used as a filler. Several medications indicated that they were dye, tartrazine, or gluten free. Three medications were found to contain soybean oil and one was found to contain peanut oil.

CONCLUSIONS

Although there are documented reactions to excipients in other products in the literature, few reports outline reactions to excipients in oral dermatologic medications. Whether this low frequency is accurate or whether it is due to a lack of reporting remains unknown. If the latter reasoning is correct, dermatologists must be more aware of these possible reactions. This article serves as a reference guide for dermatologists to aid in prescribing medications to individuals with known sensitivities and to assist in working up patients with suspected reactions to inert ingredients.

The role of diet in symptoms of irritable bowel syndrome in adults: a narrative review

This review summarizes what is known about the effect of diet on irritable bowel syndrome (IBS) symptoms emphasizing data from randomized, controlled clinical trials. Studies suggest that IBS symptoms in one quarter of patients may be caused or exacerbated by one or more dietary components. Recent studies indicate that a diet restricted in fermentable, poorly absorbed carbohydrates, including fructose, fructans (present in wheat and onions), sorbitol, and other sugar alcohols is beneficial, but confirmatory studies are needed. Despite a long history of enthusiastic use, fiber is marginally beneficial. Insoluble fiber may worsen symptoms. Some patients with IBS, especially those with constipation, will improve with increased intake of soluble fiber. Prebiotic fibers have not been adequately tested. Daily use of peppermint oil is effective in relieving IBS symptoms. The usefulness of probiotics in the form of foods such as live-culture yogurt and buttermilk for IBS symptoms is not established. In clinical practice, it is very difficult to establish that a patient's symptoms result from an adverse reaction to food. A double blind placebo-controlled food challenge is the most reliable method, but it is not suitable for routine clinical use. A modified exclusion diet and stepwise reintroduction of foods or trials of eliminating classes of food may be useful.

Parent-reported adverse food reactions in Hong Kong Chinese pre-schoolers: epidemiology, clinical spectrum and risk factors

The epidemiology of adverse food reactions (AFRs), including the potentially life-threatening food allergy (FA), in Asia is unclear. AFR is believed to be less prevalent than in Caucasians. This study determines the prevalence, clinical features and risk factors for parent-reported AFR in Chinese pre-school children in Hong Kong. Children aged 2-7 yr living in Hong Kong were recruited through local nurseries and kindergartens to ascertain the occurrence and clinical spectrum of AFR and other atopic disorders. Subjects' parents answered a self-administered questionnaire that was modified and validated based on the International Study of Asthma and Allergy in Childhood. A total of 3827 children from 21 nurseries and kindergartens returned the study questionnaires, and information on AFR was analyzable for 3677 (96.1%) children. The prevalence rates of parent-reported AFR and parent-reported, doctor-diagnosed AFR were 8.1% and 4.6%, respectively, whereas 5.0% of pre-schoolers had doctor-diagnosed asthma. The six leading causes of AFR were shellfish (15.8%), egg (9.1%), peanut (8.1%), beef (6.4%), cow's milk (5.7%), and tree nuts (5.0%). When compared with children born and raised in Hong Kong, children born in mainland China (n = 253) had less parent-reported AFR (4.0% vs. 6.7%; p = 0.016). On logistic regression, parent-reported AFR was associated with younger age (p = 0.010), born in mainland China (p = 0.038), and AFR history in father (p = 0.001), mother (p < 0.001), siblings (p = 0.020), and paternal history of rhinitis (p = 0.044). This study shows that AFR is a common atopic disorder in Hong Kong pre-school children, and prevalence rates are comparable to the Caucasians.

Quality-of-life assessment in Chinese families with food-allergic children

BACKGROUND

Caucasian families with food-allergic children have a compromised quality of life (QoL) for fear of life-threatening food reactions. Such data are limited in Asian children. Based on our recent questionnaire-based survey, 8.1% of young children recruited from local nurseries and kindergartens had parent-reported adverse food reactions (AFRs).

OBJECTIVE

This study tested the robustness of the Chinese Food Allergy Quality of Life-Parental Burden questionnaire (FAQL-PB) and assessed QoL in families with childhood AFR. The correlations among FAQL-PB items were evaluated by factor analysis.

METHODS

Two hundred and ninety-eight of 3677 children aged 2-7 years had parent-reported AFR, and 197 (66.1%) of them completed the 17 items of our self-administered FAQL-PB. Six hundred and thirty-nine (18.9%) children without AFR returned this questionnaire. Factor analysis was used to delineate the inter-relationship among the FAQL-PB items.

RESULTS

Cronbach alpha for our Chinese FAQL-PB was 0.976, and the median (interquartile range) FAQL-PB scores of children with and without parent-reported AFR were 0.10 (0.02-0.32) and 0 (0-0.18), respectively (P < 0.001). Factor analysis confirmed excellent correlations between FAQL-PB items. The 17 items were clustered into two factors, which explained 79.7% of the total variance. Among children with AFR, FAQL-PB scores increased with increasing numbers of foods that caused AFRs (P < 0.001 for trend). Thirty (15.2%) children had impaired QoL, defined as average item FAQL-PB score > or = 0.5. Impaired QoL was associated with AFR that was caused by >3 foods (P = 0.001), current food avoidance (P = 0.005) and AFR caused by peanut (P = 0.003), egg (P = 0.011) and cow's milk (P = 0.028), and current flexural dermatitis (P = 0.011).

CONCLUSIONS

FAQL-PB is a robust measure of AFR-specific parental QoL, which is impaired in Chinese children with parent-reported AFR. Flexural dermatitis, current food avoidance and AFR caused by multiple foods are independent risk factors for lower parental QoL.

Cow's milk protein sensitivity assessed by the mucosal patch technique is related to irritable bowel syndrome in patients with primary Sjögren's syndrome

Introduction

Patients with primary Sjögren's syndrome (pSS) are reported to have a variety of gastrointestinal symptoms partly attributed to an overrepresentation of celiac disease. We have observed that irritable bowel syndrome (IBS)-like symptoms are frequent complaints in this patient group. Allergic manifestations to various drugs are also common in pSS. A role of food allergy in IBS has been proposed.

Objective

This study is aimed at evaluating the mucosal response to rectal challenge with cow's milk protein (CM) in patients with pSS and relates possible CM reactivity to their intestinal symptoms.

Methods

A rectal challenge with CM was performed in 21 patients with pSS and 18 healthy controls. Fifteen hours after challenge the mucosal production of nitric oxide (NO) and the release of myeloperoxidase (MPO) as signs of mucosal inflammatory reaction were measured using the mucosal patch technique.

Results

Eight out of 21 patients with pSS had a definite increase of mucosal NO synthesis and the luminal release of MPO after rectal CM challenge. This sign of milk sensitivity was not linked to IgG/IgA antibodies to milk proteins. The symptoms for IBS according to Rome III criteria were fulfilled in 13 patients. All patients who were CM sensitive suffered from IBS. In a small open study, patients reactive to CM reported an improvement of intestinal symptoms on a CM-free diet.

Conclusion

A rectal mucosal inflammatory response after CM challenge is seen in 38% of patients with pSS as a sign of CM sensitivity. IBS-like symptoms were common in pSS, linked to CM sensitivity.

Psychological burden of food allergy

One fifth of the population report adverse reactions to food. Reasons for these symptoms are heterogeneous, varying from food allergy, food intolerance, irritable bowel syndrome to somatoform or other mental disorders. Literature reveals a large discrepancy between truly diagnosed food allergy and reports of food allergy symptoms by care seekers. In most studies currently available the characterization of patient groups is incomplete, because they did not distinguish between immunologic reactions and other kinds of food reactions. In analysing these adverse reactions, a thorough physical and psychological diagnostic approach is important. In our qualitative review, we present those diagnostic measures that are evidenced-based as well as clinically useful, and discuss the various psychological dimensions of adverse reactions to food. It is important to acknowledge the complex interplay between body and mind: Adults and children suffering from food allergy show impaired quality of life and a higher level of stress and anxiety. Pavlovian conditioning of adverse reactions plays an important role in maintaining symptoms. The role of personality, mood, or anxiety in food reactions is debatable. Somatoform disorders ought to be identified early to avoid lengthy and frustrating investigations. A future task will be to improve diagnostic algorithms, to describe psychological aspects in clearly characterised patient subgroups, and to develop strategies for an optimized management of the various types of adverse reactions to food.

The prevalence, cost and basis of food allergy across Europe

The development of effective management strategies to optimize the quality of life for allergic patients is currently hampered by a lack of good quality information. Estimates of how many individuals suffer from food allergy and the major foods involved vary widely and inadequacies of in vitro diagnostics make food challenges the only reliable means of diagnosis in many instances. The EuroPrevall project brings together a multidisciplinary partnership to address these issues. Cohorts spanning the main climatic regions of Europe are being developed in infants through a birth cohort, community surveys in school-age children and adults and an outpatient clinic study. Confirmatory double-blind placebo-controlled food challenge diagnosis is being undertaken using foods as they are eaten with titrated doses to allow no-effect and lowest-observable effect levels for allergenic foods to be determined. The cohorts will also facilitate validation of novel in vitro diagnostics through the development of the EuroPrevall Serum Bank. Complementary studies in Ghana, western Siberia, India and China will allow us to gain insights into how different dietary patterns and exposure to microorganisms affect food allergies. New instruments to assess the socioeconomic impact of food allergy are being developed in the project and their application in the clinical cohorts will allow, for the first time, an assessment to be made of the burden this disease places on allergy sufferers and their communities.

Adverse reactions to food and clinical expressions of food allergy

Adverse reactions to foods are frequent in everyday life. They are divided into toxic and immunologic food reactions. The awareness of toxic food reactions among adverse reactions to food is essential for correct diagnosis. Enzymatic food intolerance, adverse reactions to food or food additives, pharmacologic food intolerance, psychosomatic factors, food allergy with classic symptoms (anaphylaxis, urticaria-angioedema), atopic dermatitis, contact dermatitis (protein), upper and lower respiratory symptoms like rhinitis or asthma, and gastrointestinal disorders (oral allergy syndrome, colic, nausea, vomiting, diarrhea, abdominal pain) are discussed. Target organs throughout the body-ear, eye, pharynx, skin, lung, joints, and muscles-can be involved. The gold standard in diagnosis is a double-blind, placebo-controlled food challenge test. The diagnostic tools available for most food-related disorders are the skin-prick test and radioallergosorbent test. The treatment of food-induced urticaria consists of elimination of the offending food or substance from the diet, use of antihistamines, and immunotherapy.

Perceived food intolerance in subjects with irritable bowel syndrome-- etiology, prevalence and consequences

OBJECTIVES

This study estimates the prevalence of perceived food intolerance and its consequences in subjects with irritable bowel syndrome (IBS), evaluates the utility of common tests for food intolerance, studies the relation between perceived food intolerance and other disorders, and discusses the etiology.

DESIGN

Cross-sectional study.

SETTING

National health survey.

SUBJECTS

A selection of the population (n=11,078) in Oppland county, Norway, was invited to a health screening, and a sample of subjects with IBS were included in the study.

INTERVENTIONS

A medical history of food intolerance, musculoskeletal pain, mood disorders and abdominal complaints was taken, and tests were performed for food allergy and malabsorption. A dietician evaluated the dietary habits of the subjects.

RESULTS

Out of 4,622 subjects with adequately filled-in questionnaires, 84 were included in the study, 59 (70%) had symptoms related to intake of food, 62% limited or excluded food items from the diet and 12% had an inadequate diet. The mean numbers of food items related to symptoms and the number of foods limited or excluded from the diet were 4.8 and 2.5, respectively. There were no associations between the tests for food allergy and malabsorption and perceived food intolerance. Perceived food intolerance was unrelated to musculoskeletal pain and mood disorders.

CONCLUSIONS

Perceived food intolerance is a common problem with significant nutritional consequences in a population with IBS. The uselessness of current antibody tests and tests for malabsorption and the lack of correlation to psychiatric co-morbidity make the etiology obscure.

Time-dependent conversion of benzyl alcohol to benzaldehyde and benzoic acid in aqueous solutions

The oxidative reaction: benzyl alcohol-benzaldehyde-benzoic acid was investigated in time in aqueous solutions of benzyl alcohol widely used as a preservative in medicine and cosmetology. The solutions of benzyl alcohol were stored at concentrations from 0.005 to 2.09 mg/ml for a long time under different conditions. The presence of benzaldehyde and benzoic acid in these solutions was controlled by liquid chromatography on silica sorbent in water. The content of benzoic acid and potentially toxic benzaldehyde in solutions depending on the initial concentration of benzyl alcohol, on time, and on storage conditions was evaluated quantitatively.

IgE sensitization, respiratory allergy symptoms, and heritability independently increase the risk of otitis media with effusion

BACKGROUND AND AIMS

Epidemiological evidence examining the role of atopy and/or allergy in the pathogenesis of otitis media with effusion (OME) is inconclusive. The aim of this study was to assess any increased risk for OME attributable to allergy-related factors, in a well-characterized population using a case-control design and multivariate analysis.

SUBJECTS AND METHODS

Eighty-eight 1-7-year-old children with OME, diagnosed by clinical and tympanometric evaluation and 80 matched controls were enrolled. A standardized questionnaire was completed, in order to assess factors related to OME and allergy-related symptoms and diagnoses using strict clinical definitions. Specific IgE was measured by skin-prick tests and/or CAP-FEIA.

RESULTS

The patient and control groups were well matched. Factors conferring increased risk for OME in the univariate analysis included IgE sensitization, dyspnea, wheezing, asthma, paroxysmal sneezing, rhinitis, eczema, 'any allergic disease,' family history of otitis media, and family history of allergy. After multivariate analysis IgE sensitization, wheezing, nasal obstruction, family history of otitis, and child-care attendance remained as independent risk factors for development of OME.

CONCLUSION

IgE sensitization and respiratory allergy symptoms are independent risk factors for the development of OME, suggesting that both immunological and mechanical pathways may contribute to the development of the disease. Otitis heritability provides additional risk, as well as frequent exposure to viral upper respiratory tract infections in children attending daycare. Treatment and/or prevention of OME using anti-allergic medications should be further examined.

Oral challenge test for the diagnosis of gingival hypersensitivity to apple: A case report

Food intolerance is the term used to describe a hypersensitivity reaction to a food component. These reactions refer to the drug-like side effects caused by a range of chemicals that may be present in food as natural or added components. The range of symptoms which can be induced by food intolerance are very similar to those caused by food allergy, oral allergy syndrome, acute infectious diseases and vesiculobullous disorders; so that on initial presentation, it can be difficult to differentiate between these conditions. A 48-year-old woman with complaints of allergic symptoms was examined with skin prick test (SPT), specific IgE analysis, and oral challenge test for definitive allergen determination. The patient was negative in both specific IgE detection and SPT with commercial extracts of apple, whereas the oral challenge test revealed positive objective symptoms with blister and ulcer formation. Apple has been reported to be the cause of food allergy. To our knowledge, there is no report of apple intolerance in which the lesions are only confined to gingival tissues.

Adverse reactions to food additives

OBJECTIVES

To summarize the literature related to the classification of food additives and their reported adverse reactions and to provide a practical approach for evaluation of patients suspected of having such reactions.

DATA SOURCES

Information was derived from selected reviews and original articles published in peer-reviewed journals and from authoritative textbook chapters, supplemented by the clinical experience of the authors.

STUDY SELECTION

Priority was given to studies that used blinded, placebo-controlled oral challenges to confirm adverse reactions to food additives. In addition, selected, appropriately evaluated case reports are included.

RESULTS

A large number of food additives are widely used in the food industry. Adverse reactions to additives seem to be rare but are likely underdiagnosed in part due to a low index of suspicion. Numerous symptoms have been attributed to food additive exposure, but the cause-and-effect relationship has not been well demonstrated in all.

CONCLUSIONS

Reactions to food additives should be suspected in patients who report symptoms to multiple unrelated foods or to a certain food when commercially prepared but not when homemade and the allergy evaluation rules out a role for food protein. It is also prudent to investigate food additives in patients considered to have idiopathic reactions. There is a minor role for skin testing or in vitro testing. Oral challenge testing with common additives, preferably preceded by a trial of an additive-free diet, is the definitive procedure for detecting the offending agent. Once the specific additive is identified, management is basically avoidance of all its forms.

Food allergies and food intolerances

Adverse reactions to foods, aside from those considered toxic, are caused by a particular individual intolerance towards commonly tolerated foods. Intolerance derived from an immunological mechanism is referred to as Food Allergy, the non-immunological form is called Food Intolerance. IgE-mediated food allergy is the most common and dangerous type of adverse food reaction. It is initiated by an impairment of normal Oral Tolerance to food in predisposed individuals (atopic). Food allergy produces respiratory, gastrointestinal, cutaneous and cardiovascular symptoms but often generalized, life-threatening symptoms manifest at a rapid rate-anaphylactic shock. Diagnosis is made using medical history and cutaneous and serological tests but to obtain final confirmation a Double Blind Controlled Food Challenge must be performed. Food intolerances are principally caused by enzymatic defects in the digestive system, as is the case with lactose intolerance, but may also result from pharmacological effects of vasoactive amines present in foods (e.g. Histamine). Prevention and treatment are based on the avoidance of the culprit food.

Oral food challenges in children in Italy

BACKGROUND

Epidemiological surveys identify a 900,000-strong potential paediatric population who may self-report with food allergy in Italy. As the reference test is the double-blind, placebo-controlled food challenge for diagnosis, we carried out a nation-wide questionnaire survey of hospital-based paediatric allergy centres between 1 January and 30 June 2003.

METHODS

All registered centres received a 27-point questionnaire polling logistics and protocols of oral food challenge. Items polled included medical facilities and personnel, selection of patients, foods tested, blinding, placebo use, evaluation criteria, number of tests and positive outcome rates in 2002.

RESULTS

Two hundred and two of 456 responders (44.3%) carried out food challenges (a ratio of one centre to 37,400 children in the general population). 11,728 challenges were performed in 2002 (an average of 58 procedures per centre; range: 1-500) and 3350 procedures were claimed positive (28.6%). Cow's milk was tested by all centres, egg by 77.2%, beef by 19.8% and cereals, peanuts, fish or fruit collectively by 37.6%. Twenty-nine of 202 centres performed blinded tests, 18 of which under double-blinded conditions. In cow's milk challenges, placebos included lyophilized cow's milk capsules, soy formula, extensive whey hydrolysate or extensive casein hydrolysate.

CONCLUSION

Our survey reveals great differences in challenge test criteria, facilities and procedures and that many centres perform relatively few procedures. This argues in favour of greater rationalization in the allocation of tertiary-level resources before procedure standardization can be contemplated in the diagnostic workup of food allergy.

The SAFE project: 'plant food allergies: field to table strategies for reducing their incidence in Europe' an EC-funded study

The true prevalence of food allergy as an IgE mediated reaction is still under discussion. Using apple as a model allergen source a multidisciplinary consortium worked together at developing various strategies for reducing the incidence of fruit allergies in an EC-funded project. Patient allergen profiles were established using in vitro and in vivo tests with respect to geographic area and mild or severe symptoms. Apple allergens (Mal d 1-Mal d 4) were characterised, variants identified, cloned and sequenced. These individual allergens were used to increase the sensitivity and specificity of diagnosis. Furthermore, they provided better prognosis of disease severity. RT-PCR and ELISA were developed for determining the allergen specific mRNA and expressed allergenic protein in a large number of apple cultivars. Similarly, changes in allergen characteristics from harvest through storage to processing and the impact of agronomic practices were investigated. Allergen genes were mapped on a molecular linkage map of apple. The biological function of Mal d 1 was studied using the RNA interference strategy. Finally, consumer attitudes in Northern, Central and Southern Europe were gauged on the acceptability of low allergen cultivars or a GMO and its impact on product quality.

Food hypersensitivity in Portuguese adults

OBJECTIVE

To describe the frequency and epidemiological features of self-reported food hypersensitivity in Portuguese adults.

DESIGN

Cross-sectional.

SETTING

Participants were selected by random digit dialing among residents of Porto.

SUBJECTS

In total, 659 individuals over 39 y were asked to recall the occurrence of food hypersensitivity, and to describe the most serious episode. The adoption of eviction diets and previous medical diagnosis of food allergy were recorded, and recent dietary intake was evaluated using a validated food frequency questionnaire.

RESULTS

Self-reported food allergy was more frequent in women than men (7.3 vs 1.9%, P<0.01) and decreased with age. Age- and sex-standardized (European population > or =40 y) prevalence of food hypersensitivity was 4.8% (95% CI 3.4-6.9%). Most subjects (67.6%) referred allergy to a single food, fresh fruits being the more frequently incriminated (25%). Approximately 90% that reported food allergy declared the adoption of eviction diets, although 53% in fact ingested the incriminated foods during the previous year.

CONCLUSIONS

The adult prevalence of food hypersensitivity in Porto is one of the lowest observed worldwide, probably reflecting specificities of the genetic make-up and dietary patterns of our population.

Interpretation of subjective symptoms in double-blind placebo-controlled food challenges - interobserver reliability

BACKGROUND

Subjective symptoms after food challenges are difficult to interpret and no standard is available. We discuss a strategy for how to interpret a diary. Furthermore, the interobserver reliability is evaluated.

METHODS

Diaries for 32 patients with subjective symptoms were used. The diaries were re-evaluated with a predefined strategy by three independent observers.

RESULTS

The proportion of positives was 21.9% among the old diagnoses, according to the new approach 34.4% (observers I and II) and 37.5% (observer III) were positive. The new approach had high interobserver reliability (97 and 100%).

CONCLUSIONS

The proportion of positives depends on how subjective symptoms are interpreted. Interpretations of subjective symptoms in diaries could be made with high interobserver reliability.

Prevalence of adverse reactions to food in Germany - a population study

OBJECTIVE

A population study was performed to identify the prevalence of all kinds of adverse reactions to food.

METHODS

In a representative cross-sectional survey performed in 1999 and 2000 in Berlin, 13 300 inhabitants of all ages were addressed by questionnaire. This questionnaire was answered by 4093 persons. All respondents mentioning any sign of food intolerance or the existence of allergic diseases (n = 2298) were followed up by telephone and, in case food intolerance could not be ruled out by patient history, were invited to attend to the clinic for personal investigation including double-blind, placebo-controlled food challenge tests (DBPCFC).

RESULTS

The self-reported lifetime prevalence of any adverse reaction to food in the Berlin population (mean age 41 years) was 34.9%. Eight hundred and fourteen individuals were personally investigated according to the guidelines. The point prevalence of adverse reactions to food confirmed by DBPCFC tests in the Berlin population as a mean of all age groups was 3.6% (95% confidence interval [3.0-4.2%]) and 3.7% in the adult population (18-79 years, 95% confidence interval [3.1-4.4.%]). Two and a half percent were IgE-mediated and 1.1% non-IgE-mediated, females were more frequently affected (60.6%). Based on a statistical comparison with available data of adults from the nationwide German Health Survey from 1998, adverse reactions to food in the adult population of Germany (age 18-79) were calculated with 2.6% [2.1-3.2%]).

CONCLUSIONS

The study gives for the first time information about the point prevalence of both immunological and nonimmunological adverse reactions to food and underlines the relevance of this issue in public health. The data also show that an individualized stepwise approach including provocation tests is mandatory to confirm the diagnosis.

Monosodium benzoate hypersensitivity in subjects with persistent rhinitis

BACKGROUND

Very few data are available from the literature on whether nonatopic subjects affected by persistent rhinitis may show the appearance of objective symptoms of rhinitis after the ingestion of food additives such as tartrazine (E102), erythrosine (E127), monosodium benzoate (E211), p-hydroxybenzoate (E218), sodium metabisulphite (E223), and monosodium glutamate (E620). It is still unclear whether the ingestion of food additive may cause, as well, a consensual reduction of nasal peak inspiratory flow (NPIFR). Therefore, we used a double-blind placebo-controlled (DBPC) study to evaluate this hypothesis.

PATIENTS AND METHODS

Two hundred and twenty-six consecutive patients (76 males and 150 females) aged 12-60 years (mean age 40.2 +/- 16.3 years). After 1 month of an additive-free diet regimen, an open challenge was carried out (food additive-rich diet for 2 weeks). After this period, challenges were administered in a DBPC manner using the above-mentioned substances under investigation.

RESULTS

Twenty of 226 subjects (8.8%) reported an improvement of the symptoms of rhinitis after additive-free diet. More precisely, six of 226 (2.6%) were symptom-free and 14 of 226 (6.2%) showed an improvement in their symptoms after an additive-free diet. As far as the results for DBPC are concerned, 20 challenges with monosodium benzoate induced both objective (i.e. sneezing and rhinorrhoea) and subjective symptoms (nasal blockage and nasal itching) of rhinitis with reduction of NPIFR >/=20%, 45 challenges induced subjective symptoms of rhinitis (i.e. nasal blockage and nasal itching), without reduction of NPIFR >/=20% of the basal value, two with tartrazine, seven with erythrosine, 19 with monosodium benzoate, three with p-hydroxybenzoate, six with sodium metabisulphite, and eight with monosodium glutamate, respectively.

CONCLUSIONS

The observation that nonatopic persistent rhinitis may be caused by the frequent, probably daily, ingestion of small doses of a nontolerated substance is intriguing and suggests that at least some patients with 'chronic vasomotor rhinitis' may be intolerant to a particular food additive. Therefore, food additives can be considered triggers or aggravating factors, rather than aetiological factors.