The majority of infants with wheezing have transient conditions associated with diminished airway function at birth and do not have increased risks of asthma or allergies later in life. In a substantial minority of infants, however, wheezing episodes are probably related to a predisposition to asthma.

No abstract

We investigated the association of self-reported asthma or allergic rhinitis with serum IgE levels and skin-test reactivity to allergens in 2657 subjects in a general-population study. Regardless of the subjects' status with respect to atopy or their age group, the prevalence of asthma was closely related to the serum IgE level standardized for age and sex (P less than 0.0001), and no asthma was present in the 177 subjects with the lowest IgE levels for their age and sex (greater than 1.46 SD below the mean). The log odds ratio increased linearly with the serum IgE level after we controlled for possible confounders and the degree of reactivity to skin tests. In contrast, allergic rhinitis appeared to be associated primarily with skin-test reactions to common aeroallergens, independently of the serum IgE level. We conclude that asthma is almost always associated with some type of IgE-related reaction and therefore has an allergic basis, although not all the allergic stimuli that cause asthma appear to have been included in the battery of common aeroallergens we used to assess atopic status. These findings challenge the concept that there are basic differences between so-called allergic ("extrinsic") and nonallergic ("intrinsic") forms of asthma.

No abstract

Background-Incidence of asthma increases during the early adult years, but the relative influence of sex and early life factors in determining newly diagnosed asthma in young adults is unknown.

Background-Recent studies have suggested that a restrictive pattern assessed with a single spirometry is associated with increased morbidity and mortality. In this study, we sought to determine demographic, clinical, and mortality profiles of subjects with either a recurrent or inconsistent restrictive spirometric pattern assessed prospectively.

Background The association between vitamin D status at birth and childhood allergic outcomes is uncertain. The desert climate of Tucson offers a unique setting for studying the health effects of higher exposure to vitamin D. Objective To assess relations between cord blood 25-hydroxyvitamin D (25[OH]D) levels and allergic outcomes through age 5 years. Methods Cord blood 25(OH)D levels were measured in 219 participants in the Tucson Infant Immune Study, a population-based birth cohort. Plasma total IgE and specific IgE to 6 aeroallergens were measured at 1, 2, 3 and 5 years. Skin-prick test (SPT) positivity (wheal ≥ 3mm), and physician-diagnosed active allergic rhinitis and asthma were assessed at age 5. Longitudinal models were used to assess relations between 25(OH)D and IgE outcomes. Logistic regression models were used to assess relations with SPT positivity, allergic rhinitis and asthma. Results The median cord blood 25(OH)D level was 64 nmol/L (interquartile range, 49 to 81 nmol/L). Relative to the reference group (50–74.9 nmol/L), both low (<50 nmol/L) and high (≥ 100 nmol/L) levels were associated with increased total IgE (coef.=0.27, P=0.006; and coef.=0.27, P=0.04, respectively) and inhalant specific IgE (OR=2.4, P=0.03; and OR=4.0, P=0.01, respectively) through age 5 years. High 25(OH)D levels also were associated with increased SPT positivity (OR=4.0, P=0.02). By contrast, 25(OH)D level was not significantly associated with allergic rhinitis or asthma. Conclusion Both low and high levels of cord blood 25(OH)D were associated with increased aeroallergen sensitization. The association between vitamin D status and actual allergic diseases merits further study.

No abstract