BMI predicts exercise induced bronchoconstriction in asthmatic boys.

BACKGROUND: Exercise induced bronchoconstriction (EIB) is a frustrating morbidity of asthma in children. Obesity has been associated with asthma and with more severe EIB in asthmatic children. OBJECTIVES: To quantify the effect of BMI on the risk of the occurrence of EIB in children with asthma. METHODS: Data were collected from six studies in which exercise challenge tests were performed according to international guidelines. We included 212 Children aged 7-18 years, with a pediatrician-diagnosed mild-to-moderate asthma. RESULTS: A total of 103 of 212 children (49%) had a positive exercise challenge (fall of FEV1 ≥ 13%). The severity of EIB, as measured by the maximum fall in FEV1 , was significantly greater in overweight and obese children compared to normal weight children (respectively 23.9% vs 17.9%; P = 0.045). Asthmatic children with a BMI z-score around +1 had a 2.9-fold higher risk of the prevalence of EIB compared to children with a BMI z-score around the mean (OR 2.9; 95%CI: 1.3-6.1; P < 0.01). An increase in BMI z-score of 0.1 in boys led to a 1.4-fold increased risk of EIB (OR 1.4; 95%CI: 1.0-1.9; P = 0.03). A reduction in pre-exercise FEV1 was associated with a higher risk of EIB (last quartile six times higher risk compared to highest quartile (OR 6.1 [95%CI 2.5-14.5]). CONCLUSIONS: The severity of EIB is significantly greater in children with overweight and obesity compared to non-overweight asthmatic children. Furthermore, this study shows that the BMI-z-score, even with a normal weight, is strongly associated with the incidence of EIB in asthmatic boys.

[Peanut allergy, not always the correct diagnosis]. / Pinda-allergie, niet altijd een terechte diagnose.

BACKGROUND: Diagnosing peanut allergy in children is complicated. The clinical history can be difficult to interpret, measurement of peanut-specific immunoglobulin E (IgE) is of limited usefulness due to its poor specificity, and the gold standard (double-blind placebo-controlled food challenge) is time-consuming and labour-intensive, limiting its use in daily practice. Under-diagnosing peanut allergy is considered dangerous, because of serious reactions like anaphylaxis. As a result, there is a high probability of over-diagnosis of peanut allergy in the general population, leading to unnecessary peanut-free diets and parental anxiety. CASE DESCRIPTION: We discuss three children diagnosed with peanut allergy, and describe the clinical and diagnostic considerations of peanut allergy. After a detailed history focusing on the reproducibility of objective symptoms after exposure, peanut allergy was excluded in two cases allowing normalization of the diet and reduction of patient and parental anxiety. CONCLUSION: A detailed history, focusing on reproducible and objective symptoms, is helpful in confirmation or exclusion of the diagnosis 'peanut allergy' and can thus prevent unnecessary peanut-free diets.

Predictive value of specific IgE for clinical peanut allergy in children: relationship with eczema, asthma, and setting (primary or secondary care).

The usefulness of peanut specific IgE levels for diagnosing peanut allergy has not been studied in primary and secondary care where most cases of suspected peanut allergy are being evaluated. We aimed to determine the relationship between peanut-specific IgE levels and clinical peanut allergy in peanut-sensitized children and how this was influenced by eczema, asthma and clinical setting (primary or secondary care). We enrolled 280 children (0-18 years) who tested positive for peanut-specific IgE (> 0.35 kU/L) requested by primary and secondary physicians. We used predefined criteria to classify participants into three groups: peanut allergy, no peanut allergy, or possible peanut allergy, based on responses to a validated questionnaire, a detailed food history, and results of oral food challenges.Fifty-two participants (18.6%) were classified as peanut allergy, 190 (67.9%) as no peanut allergy, and 38 (13.6%) as possible peanut allergy. The association between peanut-specific IgE levels and peanut allergy was significant but weak (OR 1.46 for a 10.0 kU/L increase in peanut-specific IgE, 95% CI 1.28-1.67). Eczema was the strongest risk factor for peanut allergy (aOR 3.33, 95% CI 1.07-10.35), adjusted for demographic and clinical characteristics. Asthma was not significantly related to peanut allergy (aOR 1.93, 95% CI 0.90-4.13). Peanut allergy was less likely in primary than in secondary care participants (OR 0.46, 95% CI 0.25-0.86), at all levels of peanut-specific IgE.The relationship between peanut-specific IgE and peanut allergy in children is weak, is strongly dependent on eczema, and is weaker in primary compared to secondary care. This limits the usefulness of peanut-specific IgE levels in the diagnosis of peanut allergy in children.