Utility of food allergy thresholds.

Food allergy is a prevalent disease worldwide that is a significant quality-of-life burden, and accidental exposures to food allergens may elicit severe, life-threatening reactions such as anaphylaxis. The threshold level, or the dose that triggers an allergic reaction determined by oral food challenges, varies considerably among individuals suffering from food allergies. Moreover, IgE concentration, diversity, or function can only partially explain this variation in threshold; pathogenic effector TH2 cells have also been found to contribute to the eliciting dose. Though very sensitive to cofactors such as physical activity/stress, the threshold is a stable and reproducible feature of an individual's allergy over periods of many months, made clear in the past several years from treatment studies in which repeated threshold determination has been used as a treatment outcome; however, there also seem to be age-related changes at a population level. More routine determination of food allergy thresholds may help patients stratify risk to improve the management of their food allergy. Precautionary allergen labeling, such as "may contain" labels, often causes confusion since they are inconsistent and regularly contain little to trace allergen residues; thus, food products with such labeling may be unnecessarily avoided. Population-based eliciting dose levels have been determined in the literature; patients at lower risk with higher thresholds may be more confident with introducing foods with precautionary allergen labels. Understanding a patient's threshold level could aid in shared decision-making to determine the most suitable treatment options for patients, including the starting dose for oral immunotherapy and/or the use of biologics.

Analysis of Oral Food Challenge Outcomes in IgE-Mediated Food Allergies to Almond in a Large Cohort.

BACKGROUND: Although almond specific IgE-mediated food allergies have traditionally been equated with other tree nut allergies, outcomes of oral food challenges to almond and the utility of clinical testing to predict IgE-mediated almond hypersensitivity are not well known. OBJECTIVE: To describe almond oral challenge outcomes and assess the predictive value of clinical testing. METHODS: A total of 603 almond challenges performed for 590 patients, aged 1 to 66 years, were analyzed from Massachusetts General Hospital allergy practices. Reactions were graded using the Niggemann and Beyer allergic reaction grading system and the Sampson 2006 National Institute of Allergy and Infectious Diseases anaphylaxis definition. RESULTS: Almond challenges included 545 passes (92%), 15 (3%) indeterminates, and 30 (5%) failures, in contrast with 31% challenge failures for other foods. Most reactions were mild; 21 (4%) had grade 2/3 allergic symptoms, and 3 (0.5%) had anaphylaxis. Median almond specific IgE level was 0.89 kU/L (range, <0.35 to >100 kU/L), median skin prick test wheal diameter was 4.0 mm (range, 0-28 mm), and 475 subjects (81%) were sensitized to almond. Failure was associated with higher almond specific IgE level (P < .001), larger almond skin prick test wheal diameter (P = .001), higher peanut IgE level (P = .003), and a history of almond reaction (P < .029). Almond specific IgE level, almond skin prick test wheal diameter, and age at challenge combined demonstrated good predictive value for grade 2/3 allergic reactions by receiver-operating characteristic analysis (area under the curve, 0.83). CONCLUSIONS: The proportion of failed almond challenges (5%) was low in contrast with other allergens, suggesting that some almond challenges may be safely conducted with higher patient-to-staff ratios or potentially introduced at home. Although reactions are usually uncommon and mild, anaphylaxis is possible with high almond sensitization.

Cystic fibrosis on the Internet: a survey of site adherence to AMA guidelines.

OBJECTIVES: The Internet permits unprecedented and mostly unrestricted access to medical knowledge; however, concerns exist regarding viewer privacy, accountability of authorship, accuracy of information, and patient safety. To address these issues, the American Medical Association (AMA) has developed guidelines concerning web site content and visitor rights. Cystic fibrosis (CF) is the most common genetically inherited lethal disease in North America. Many Internet sites that provide information on CF have been developed, although adherence to validated guidelines for online health information is not required. The purpose of this study was to assess systematically web sites with content pertaining to CF for adherence to the published AMA guidelines. METHODS: The search term "cystic fibrosis" was entered into a commonly used search engine (Google), and the first 100 eligible sites were reviewed. Each site was examined for adherence to the AMA Guidelines for Medical and Health Information Sites on the Internet using a series of adapted questions. There were 15 questions divided into the following main categories: 1) site structure and viewer privacy, 2) author accountability, 3) scientific citation, and 4) patient safety. The number of positives for each question was tabulated. RESULTS: With respect to site structure, fewer than half (45%) of the reviewed sites indicated a date of last revision. Only 11 (11%) carried an explicit privacy policy. A responsible author or group was listed in only 43 (43%) of 100 sites. Presented data regarding CF was supported by references, sources, or expert review in only 38 (38%) of 100 sites. A medical disclaimer noting that information provided does not substitute for evaluation by a health care team was evident in only 37 (37%) sites. CONCLUSIONS: The majority of easily accessible CF informational web sites do not adhere to guidelines published by the AMA. Patients and families who use the Internet as a CF information resource should examine the web sites carefully and be familiar with the guidelines established by the AMA. Personal information is not protected, and few sites provide explicit privacy guarantees. Finally, CF care teams should inquire about Internet use by patients and families and be prepared to discuss findings from the Internet to heighten patient safety and awareness.