28 research outputs found
Multisystem reactions during egg oral food challenges may be associated with less severe reactions on initial presentation
In this study, we assessed whether multisystem reactions to egg and extensively-heated (EH) egg during OFCs were associated with a history of multisystem reactions. Records of children, who underwent OFC to egg or EH egg over a five-year period were reviewed. Of the 120 challenges, 26 (21.67 %) failed, with 38.4 % (10/26) having multisystem reactions. Of the 13 who had multisystem reactions on initial presentation, only two (15.4 %) had a similar OFC outcome. Eighty percent (8/10) of those who had a multisystem OFC reaction had a less severe initial presentation. Initial and OFC multisystem reactions were not associated with each other
Oral Food Challenge Failures Among Foods Restricted Due to Atopic Dermatitis
BACKGROUND
Recent studies have suggested that removing foods from the diet to manage atopic dermatitis (AD), based on positive allergy tests, may lead to immediate allergic reactions on reintroduction of that food.
OBJECTIVE
The purpose of this study was to examine the frequency of oral food challenge (OFC) failures among foods removed from the diet as suspected AD triggers, focusing on the five major food allergens in the US.
METHODS
OFCs to egg, milk, peanut, soy, and wheat, performed from 2008-14, at a children's hospital's allergy clinics, were reviewed. OFCs were offered based on history and laboratory values. Reasons for food avoidance were classified as food allergy (IgE-mediated reaction occurring within two hours); sensitization only (lack of introduction due to positive test results); and removal due to test results during AD evaluation.
RESULTS
There were 442 OFCs performed, with 89 failures (20.1%). Reasons for OFCs included a history of food allergy (320/442; 72.4%); food sensitization without any introduction (77/442; 17.4%); and AD (45/442; 10.2%). OFC failures among those who had food allergy (70/320; 21.9%); sensitization only (13/77; 16.9%); and suspected AD trigger (6/45; 13.3%) did not significantly differ (p=0.63). Wheat was more likely to be avoided than the other four foods for AD concerns (p<0.0001).
CONCLUSION
The frequency of OFC failure among those who removed foods suspected as AD triggers was 13.3%, indicating a loss of tolerance. Restriction of foods to manage AD must be done with caution and close monitoring
Role of the Microbiome in Allergic Disease Development
PURPOSE OF REVIEW: Evidence suggests that the microbiome of the skin, gastrointestinal tract, and airway contribute to health and disease. As we learn more about the role that the microbiota plays in allergic disease development, we can develop therapeutics to alter this pathway.
RECENT FINDINGS: Epidemiologic studies reveal that an association exists between environmental exposures, which alter the microbiota, and developing atopic dermatitis, food allergy, and/or asthma. In fact, samples from the skin, gastrointestinal tract, and respiratory tract reveal distinct microbiotas compared with healthy controls, with microbial changes (dysbiosis) often preceding the development of allergic disease. Mechanistic studies have confirmed that microbes can either promote skin, gut, and airway health by strengthening barrier integrity, or they can alter skin integrity and damage gut and airway epithelium. In this review, we will discuss recent studies that reveal the link between the microbiota and immune development, and we will discuss ways to influence these changes
Management of food allergy in the school setting
Food allergy is a growing health and safety concern that affects up to 8% of school-age children. Because children spend a significant part of their day in school, and the overall number of school-age children with food allergy has been increasing, management of food allergies relies
on the collaboration of allergists, families, and schools to treat and prevent acute allergic reactions. For schools, this involves policies centered on food allergen avoidance, preparedness with epinephrine autoinjectors, adequate school personnel training, and accommodations for an equal
opportunity learning environment. Partnerships with allergists, primary care providers, students, families, school nurses, and school staff are vital for creating individualized and effective care plans that will allow all children, including those with food allergies, a safe and nurturing
learning environment
In children, the microbiota of the nasopharynx and bronchoalveolar lavage fluid are both similar and different
RATIONALE:
Sputum and bronchoalveolar lavage fluid (BALF) are often obtained to elucidate the lower airway microbiota in adults. Acquiring sputum samples from children is difficult and obtaining samples via bronchoscopy in children proves challenging due to the need for anesthesia and specialized procedural expertise; therefore nasopharyngeal (NP) swabs are often used as surrogates when investigating the pediatric airway microbiota. In adults, the airway microbiota differs significantly between NP and BALF samples however, minimal data exist in children.
OBJECTIVES:
To compare NP and BALF samples in children undergoing clinically indicated bronchoscopy.
METHODS:
NP and BALF samples were collected during clinically indicated bronchoscopy. Bacterial DNA was extracted from 72 samples (36 NP/BALF pairs); the bacterial V1-V3 region of the 16S rRNA gene was amplified and sequenced on the Illumina Miseq platform. Analysis was performed using mothur software.
RESULTS:
Compared to NP samples, BALF had increased richness and diversity. Similarity between paired NP and BALF (intra-subject) samples was greater than inter-subject samples (Pβ=β0.0006). NP samples contained more Actinobacteria (2.2% vs 21%; adjusted Pβ=β1.4βΓβ10-6 ), while BALF contained more Bacteroidetes (29.5% vs 3.2%; adjusted Pβ=β1.2βΓβ10-9 ). At the genus level several differences existed, however Streptococcus abundance was similar in both sample types (NP 37.3% vs BAL 36.1%; adjusted Pβ=β0.8).
CONCLUSION:
Our results provide evidence that NP samples can be used to distinguish differences between children, but the relative abundance of organisms may differ between the nasopharynx and lower airway in pediatric patients. Studies utilizing NP samples as surrogates for the lower airway should be interpreted with caution
Designer covalent heterobivalent inhibitors prevent IgE-dependent responses to peanut allergen
Allergies are a result of allergen proteins cross-linking allergen-specific IgE (sIgE) on the surface of mast cells and basophils. The diversity and complexity of allergen epitopes, and high-affinity of the sIgE-allergen interaction have impaired the development of allergen-specific inhibitors of allergic responses. This study presents a design of food allergen-specific sIgE inhibitors named covalent heterobivalent inhibitors (cHBIs) that selectively form covalent bonds to only sIgEs, thereby permanently inhibiting them. Using screening reagents termed nanoallergens, we identified two immunodominant epitopes in peanuts that were common in a population of 16 allergic patients. Two cHBIs designed to inhibit only these two epitopes completely abrogated the allergic response in 14 of the 16 patients in an in vitro assay and inhibited basophil activation in an allergic patient ex vivo analysis. The efficacy of the cHBI design has valuable clinical implications for many allergen-specific responses and more broadly for any antibody-based disease
Detection of Pathogenic Bacteria During Rhinovirus Infection is Associated with Increased Respiratory Symptoms and Exacerbations of Asthma
Background Detection of either viral or bacterial pathogens is associated with wheezing in children, however the influence of both bacteria and virus on illness symptoms has not been described. Objective We evaluated bacterial detection during peak RV season in children with and without asthma to determine if an association exists between bacterial infection and the severity of RV illnesses. Methods 308 children (166 with asthma, 142 without asthma) ages 4β12 years provided five consecutive weekly nasal samples during September, and scored cold and asthma symptoms daily. Viral diagnostics and quantitative PCR for Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were performed on all nasal samples. Results Detection rates were 53%, 17% and 11% for H. influenzae, S. pneumoniae and M. catarrhalis, respectively, with detection of RV increasing the risk of detecting bacteria within the same sample (OR 2.0, 95% CI 1.4β2.7, p<0.0001) or the following week (OR 1.6 (1.1β2.4), p=0.02). In the absence of RV, S. pneumoniae was associated with increased cold symptoms (mean 2.7 (95% CI 2.0β3.5) vs. 1.8 (1.5β2.2), p=0.006) and moderate asthma exacerbations (18% (12%β27%) vs. 9.2% (6.7%β12%), p=0.006). In the presence of RV, S. pneumoniae was associated with increased moderate asthma exacerbations (22% (16%β29%) vs. 15% (11%β20%), p=0.01). Furthermore, M. catarrhalis detected alongside RV increased the likelihood of experiencing cold and/or asthma symptoms compared to isolated detection of RV (OR 2.0 (1.0β4.1), p=0.04). Regardless of RV status, H. influenzae was not associated with respiratory symptoms. Conclusion RV infection enhances detection of specific bacterial pathogens in children with and without asthma. Furthermore, these findings suggest that M. catarrhalis and S. pneumoniae contribute to the severity of respiratory illnesses, including exacerbations of asthma