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Background: Atopic, eosinophilic, and TH2-high asthma phenotypes may overlap, but the extent is unknown. Understanding the overlap across these phenotypes may be useful in guiding asthma patient care., Objective: To examine the frequency and overlap of atopic, eosinophilic, and TH2-high asthma phenotypes., Methods: We analyzed 2005 to 2006 data from the National Health and Nutrition Examination Survey. Patients with asthma were identified based on the participant self-report. Eosinophilic asthma was defined as a blood eosinophil cutoff point of ≥150, 300, or 400/μL. Atopic asthma was defined as having an allergen-specific IgE level of ≥0.35 IU/mL for any of the 9 perennial allergens tested. TH2-high asthma was defined as a total serum IgE of ≥100 IU/mL and a blood eosinophil count of ≥140/μL., Results: The study included 269 children and 310 adults. Depending on the eosinophil cutoff used, 31% to 78% of children and 21% to 69% of adults with asthma were classified as having eosinophilic asthma. In addition, 63% of children and 61% of adults were classified as having atopic disease and 48% of children and 37% of adults as having TH2-high asthma. At a higher eosinophil cutoff point, a greater proportion of eosinophilic asthma can be classified as atopic or TH2 high, but a lower proportion of atopic or TH2-high asthma can be classified as eosinophilic. Approximately 70% or more of children and adults with asthma were 1 of these 3 phenotypes., Conclusion: A considerable overlap among eosinophilic, atopic, and TH2-high asthma phenotypes exists in a general asthma population., (Copyright © 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: The increase in pediatric allergy and asthma parallels the increase in use of antibiotics. Antibiotics disturb the flora of the gastrointestinal tract, possibly perturbing the developing immune system., Objective: We evaluated whether antibiotic use during early infancy increased the risk for atopy., Methods: Antibiotic prescriptions documented in medical records were collected from a birth cohort born from 1987 through 1989 (n = 725). At 6 to 7 years of age, 448 were followed by means of examination, including skin prick tests and serum IgE measurements to common allergens., Results: Adjusted odds ratios (aORs) and 95% CIs were calculated comparing children with any versus those with no antibiotic use in the first 6 months and the outcomes of atopy (any positive skin test response), seroatopy (any positive specific IgE test result), either atopy or seroatopy, and both atopy and seroatopy. Atopy increased with antibiotic use approaching statistical significance (aOR, 1.48; 95% CI, 0.94-2.34; P = .09); however, the risk was concentrated among children with less than 2 pets in the home (aOR, 1.73; 95% CI, 1.07-2.80; P = .024) and children breast-fed for 4 or more months (aOR, 3.02; 95% CI, 1.27-7.17; P = .013). The aORs were generally in the same direction for seroatopy and the combined categories., Conclusion: Antibiotic use in early life appears to contribute to increased risk for atopy in certain subgroups of children.

A world wide web database was established that tracked features of eosinophil-associated gastrointestinal disorders; 80% had coexisting atopic disease, 62% had food sensitization, and 16% had an immediate family member with a similar disorder. Developmental delay, seizure disorders, and congenital anomalies were seen in a proportion of respondents. The world wide web has proven to be an efficient tool to gather patient information, allowing us to define distinguishing features of various eosinophil-associated gastrointestinal disorders and to establish that these disorders have strong genetic and allergic components.

Background: Previous literature has indicated that environmental exposures in childhood influence development of atopic sensitization., Objective: We sought to study the association between childhood environment and adult atopy., Methods: Thirteen thousand nine hundred thirty-two subjects aged 20 to 44 years from 36 areas in Europe, New Zealand, the United States, and Australia took part in the European Community Respiratory Health Survey, answering interviewer-led questionnaires and providing blood tests for measurement of specific IgE to grass, house dust mite, cat, and Cladosporium allergens., Results: Atopy was negatively associated with family size (OR = 0. 93; 95% CI = 0.90-0.96 per 1 sib), partly attributable to an independent protective effect of a greater number of brothers (OR = 0.92; 95% CI = 0.89-0.95 per 1 brother). Accounting for total number of siblings, no further influence was detected for number of older or younger siblings. Bedroom sharing was associated with a lower prevalence of atopy, particularly to cat allergen. A protective effect of family size and bedroom sharing could only be detected in subjects reporting no parental allergy (family size, test for interaction P =.012). The presence of a dog in the home in childhood was negatively associated with adult atopy (OR = 0.85, 95% CI = 0. 78-0.92), an effect that remained after adjustment for parental allergy, sibling allergy, and adult pet ownership., Conclusion: Subjects from large families with brothers, shared bedrooms, and dogs in childhood were less often atopic as adults. Our findings are consistent with the hypothesis that infectious agents could inhibit development of atopy during childhood. However, in subjects with a strong genetic predisposition, environmental factors in childhood are possibly of less importance.