Background Sensitization to food antigen can occur through cutaneous exposure. Objective We sought to test the hypothesis that epicutaneous sensitization with food antigen predisposes to IgE-mediated ...anaphylaxis on oral allergen challenge. Methods BALB/c mice were epicutaneously sensitized by repeated application of ovalbumin (OVA) to tape-stripped skin over 7 weeks or orally immunized with OVA and cholera toxin (CT) weekly for 8 weeks and then orally challenged with OVA. Body temperature was monitored, and serum mouse mast cell protease 1 levels were determined after challenge. Tissue mast cell (MC) counts were examined by using chloroacetate esterase staining. Levels of serum OVA-specific IgE and IgG1 antibodies and cytokines in supernatants of OVA-stimulated splenocytes were measured by means of ELISA. Serum IL-4 levels were measured by using an in vivo cytokine capture assay. Results Epicutaneously sensitized mice exhibited expansion of connective tissue MCs in the jejunum, increased serum IL-4 levels, and systemic anaphylaxis after oral challenge, as evidenced by decreased body temperature and increased serum mouse mast cell protease 1 levels. Intestinal MC expansion and anaphylaxis were IgE dependent because they did not occur in epicutaneously sensitized IgE−/− mice. Mice orally immunized with OVA plus CT did not have increased serum IL-4 levels, expanded intestinal MCs, or anaphylaxis after oral challenge, despite OVA-specific IgE levels and splenocyte cytokine production in response to OVA stimulation, which were comparable with those of epicutaneously sensitized mice. Conclusion Epicutaneously sensitized mice, but not mice orally immunized with antigen plus CT, have expansion of intestinal MCs and IgE-mediated anaphylaxis after single oral antigen challenge. IgE is necessary but not sufficient for food anaphylaxis, and MC expansion in the gut can play an important role in the development of anaphylaxis.
Background Children with food allergies spend a large proportion of time in school but characteristics of allergic reactions in schools are not well studied. Some schools self-designate as ...peanut-free or have peanut-free areas, but the impact of policies on clinical outcomes has not been evaluated. Objective We sought to determine the effect of peanut-free policies on rates of epinephrine administration for allergic reactions in Massachusetts public schools. Methods In this retrospective study, we analyzed (1) rates of epinephrine administration in all Massachusetts public schools and (2) Massachusetts public school nurse survey reports of school peanut-free policies from 2006 to 2011 and whether schools self-designated as “peanut-free” based on policies. Rates of epinephrine administration were compared for schools with or without peanut-restrictive policies. Results The percentage of schools with peanut-restrictive policies did not change significantly in the study time frame. There was variability in policies used by schools self-designated as peanut-free. No policy was associated with complete absence of allergic reactions. Both self-designated peanut-free schools and schools banning peanuts from being served in school or brought from home reported allergic reactions to nuts. Policies restricting peanuts from home, served in schools, or having peanut-free classrooms did not affect epinephrine administration rates. Schools with peanut-free tables, compared to without, had lower rates of epinephrine administration (incidence rate per 10,000 students 0.2 and 0.6, respectively, P = .009). Conclusions These data provide a basis for evidence-based school policies for children with food allergies. Further studies are required before decisions can be made regarding peanut-free policies in schools.
Cow's milk allergy is the most common food allergy in childhood. Many children with IgE-mediated cow's milk allergy may tolerate baked milk products, but few data exist on predictors of outcomes of ...baked milk challenges.
To determine the relation of milk protein allergen specific IgE (sIgE) levels and skin prick test (SPT) wheal size with baked milk challenge outcomes.
A retrospective medical record review was conducted of 35 baked milk challenges. SPT results, sIgE levels, demographic characteristics, and food challenge results were analyzed.
Thirty-five children underwent open challenges to baked milk and 29 (83%) passed. Of those who failed, 3 (50%) passed the initial clinic challenge but developed symptoms to ongoing exposure at home, days to months later. One child who ultimately failed at home required epinephrine. Compared with those who passed, children who failed were younger (median age, 8.9 and 3.7 years, respectively; P = .02). Children with a milk SPT wheal less than 12 mm were more than 90% likely to pass a baked milk challenge, and no child with a milk SPT wheal less than 7 mm failed a baked milk challenge. We were also able to establish more than 90% predictive values for passing baked milk challenges with a casein SPT wheal of 9 mm, a milk sIgE level of 1.0 kU/L, and a casein sIgE level of 0.9 kU/L.
Most children allergic to cow's milk tolerated baked milk. Milk protein SPT wheal may be more reliable than sIgE level in predicting outcomes of baked milk challenges. It is important to be aware of the possibility of late reactions to ongoing baked milk exposure.
Children with egg allergy may tolerate baked egg products. Ovomucoid specific IgE (sIgE) antibody levels have been suggested to predict outcomes of baked egg challenges.
We determined the ...relationship of ovomucoid and egg white sIgE levels and egg white skin prick test (SPT) wheal size with baked egg challenge outcome.
Retrospective review of 1186 patients who underwent ovomucoid sIgE blood testing. Subset analysis was of 169 patients who underwent baked egg food challenges.
Egg white sIgE, ovomucoid sIgE, and egg white SPT were different among those eating regular egg, eating baked egg only, or avoiding all egg (P < .001 for all). One hundred forty-two of 169 patients (84.0%) passed baked egg challenges. We were able to establish >90% predictive values for passing baked egg challenge for egg white sIgE, ovomucoid sIgE, and egg white SPT.No patient with egg white SPT wheal <3 mm failed a baked egg challenge. Receiver operating characteristic curve analysis of egg white sIgE, ovomucoid sIgE, and egg white SPT showed areas under the curve of 0.721, 0.645, and 0.624, respectively. No significant difference was observed among these immunologic parameters in their abilities to predict baked egg challenge outcome (P .301).
Most children with egg allergy in this study passed baked egg challenges. Ovomucoid sIgE, although a useful clinical predictor of baked egg tolerance, was not superior to egg white SPT or sIgE in predicting outcome of baked egg challenge.
After adjusting for race and season (spirometry reference values standardized by age, height and gender), NO2 was highly associated with increased airflow obstruction such that each 10ppb rise in NO2 ...exposure was associated with a 3% decline in FEV1/FVC (β: -0.03, 95% confidence interval (CI) -0.05, -0.00, p=0.03).
Conclusions By setting and continually refining ssIgE and skin prick test recommendations using the SCAMP method, allergists can better determine the risk of severe reactions and triage patients to ...the appropriate resource setting for an OFC.
Oral food challenges (OFCs) are routinely used to confirm ongoing food allergy. Serum-specific IgE (sIgE) and skin prick testing (SPT) are imperfect predictors of which patients will pass OFCs.
The ...objective of this study was to describe the design and implementation of a Standardized Clinical Assessment and Management Plan (SCAMP) to study and iteratively improve sIgE and SPT thresholds to determine when and where to conduct OFCs for patients.
Allergists consulted recommended sIgE and SPT thresholds when ordering challenges although diversions were permitted. Criteria were iteratively improved after periodic analyses of challenge outcome and diversions.
Over 3 years, allergists ordered 2368 food challenges for 1580 patients with histories of IgE-mediated reactions to food: 1386 in an outpatient clinic and 945 in a higher resource infusion center. Reactions to challenge were observed in 13% of clinic and 23% of infusion center challenges. Six patients challenged in clinic required treatment with epinephrine compared with 22 in the infusion center. The need for epinephrine was more common in patients with asthma-5% of asthmatic patients required epinephrine compared with 1% of nonasthmatic patients (P < .01). Recommended sIgE and SPT thresholds were incrementally changed and, using the control chart methodology, a significant decrease was noted in the proportion of challenges ordered in the higher resource location.
By setting and continually refining sIgE and SPT recommendations using the SCAMP method, allergists can better determine the risk of severe reaction and triage patients to the appropriate setting for an OFC.
•Avoidance diets may contribute to a heightened awareness of food and diet•There may be a modest association of food allergy, body image and eating disorders•Anorexia nervosa and avoidant restrictive ...food intake disorder receive most focus•Feelings of inadequacy and defectiveness may explain body image dissatisfaction•Comorbid food allergy and body image issues should be screened for eating disorders
Food allergy (FA) management involves avoiding allergenic foods to prevent an adverse reaction. Affected individuals spend substantial amounts of time thinking about food and the impact it has on their bodies. As such, we posit sustained awareness of food choices may contribute to distorted body image and disordered eating. We performed a narrative review to glean insight into associations between FA, body image and eating disorders.
A literature search of Scopus, PsycINFO, PubMed and Google Scholar was conducted connecting terms for “food allergy” with terms for “body image” and “eating disorders”. Title and abstract screening were independently performed by two reviewers, with relevant abstracts carried forward to full text screening.
159 articles were eligible for full text screening and a total of 12 publications were ultimately included in this narrative review, and 1 article from the grey literature. Adolescents and adults both reported feeling as though their bodies were “defective” and were found to have integrated their FA as a stable facet of their identities. In addition, FA was overwhelmingly associated with prevalence of eating disorders and eating disorder-like symptoms. Disturbed body image was found to be a mediating variable for the development of disordered patterns of eating in food allergic individuals.
Few studies appeared to consider comorbidities as confounders. Also, many studies employed convenience sampling, which does limit generalizability of conclusions.
Based on a small body of literature, there appears to be a potential association between FA and distorted body image and disordered eating.