Objective

To determine whether environmental control using nocturnal temperature controlled laminar airflow (TLA) treatment could improve the quality of life of patients with persistent atopic asthma.

Design

Randomised, double-blind, placebo-controlled, parallel-group trial.

Setting

Nineteen European asthma clinics.

Participants

312 patients aged 7–70 with inadequately controlled persistent atopic asthma.

Main outcome measure

Proportion of patients with an increase of ≥0.5 points in asthma quality of life score after 1 year of treatment.

Results

TLA devices were successfully installed in the bedrooms of 282 (90%) patients included in the primary efficacy analysis. There was a difference in treatment response rate between active (143 of 189, 76%) and placebo (56 of 92, 61%) groups, difference 14.8% (95% CI 3.1 to 26.5, p=0.02).3 In patients aged ≥12, on whom the study was powered, the difference in response rate was similar-active 106 of 143 (74%), placebo 42 of 70 (60%), difference 14.1% (0.6 to 27.7, p=0.059). There was a difference between groups in fractional exhaled nitric oxide change of −7.1 ppb (−13.6 to −0.7, p=0.03). Active treatment was associated with less increase in cat-specific IgE than placebo. There was no difference in adverse event rates between treatment groups.

Conclusion

Inhalant exposure reduction with TLA improves quality of life, airway inflammation and systemic allergy in patients with persistent atopic asthma. TLA may be a treatment option for patients with inadequately controlled persistent atopic asthma.

Trial registration number

Clinical Trials NCT00986323.

Epidemiological data provide strong evidence for a relationship between undernutrition and life-threatening infection in infants and children. However, the mechanisms that underlie this relationship are poorly understood. Through foetal life, infancy and childhood, the immune system undergoes a process of functional maturation. The adequacy of this process is dependent on environmental factors, and there is accumulating evidence of the impact of pre- and post-natal nutrition in this regard. This review outlines the impact of nutrition during foetal and infant development on the capacity to mount immune responses to infection. It provides an overview of the epidemiologic evidence for such a role and discusses the possible mechanisms involved.

Objectives: To determine whether there are any differences between children who remain mildly or moderately allergic to peanut and children with similar histories but a negative reaction on challenge with peanut.

Design: Case-controls matched for age and sex.

Setting: Children’s day wards in two teaching hospitals.

Intervention: Open food challenge with peanut.

Subjects: 15 children with resolved peanut allergy (resolvers) and 15 with persistent allergy (persisters).

Main outcome measure: Reaction on challenge with peanut, serum total and peanut specific IgE concentrations.

Results: The groups had a similar median age at first reaction to peanut (11 months, range 5-38) and similar symptoms. Allergy to other foods was less common in resolvers (2/15) than persisters (9/15) (P=0.02). On skin prick testing with peanut all 13 resolvers tested but only 3/14 persisters had a weal of <6 mm (P<0.0001). Total and peanut specific IgE concentrations did not differ much between the groups.

Conclusion: Appropriately trained clinicians must be prepared to challenge preschool children with peanut as some will be tolerant despite a history of reactions to peanut and a positive skin prick test with peanut. Preschool children whose apparent peanut allergy is refuted by food challenge show allergy to other foods less often than those in whom peanut allergy persists. The size of weal on skin prick testing to peanut predicts reactivity but not severity on peanut challenge.

Key messages Peanut allergy rarely resolves in older children and adults Skin prick testing with peanut has a high negative predictive value, but some people with positive skin tests do not react to peanut challenge Some preschool children with a convincing history of reaction to peanut may become tolerant of peanut. Such children have fewer other manifestations of atopy than children whose peanut allergy persists Paediatricians must be prepared to undertake peanut challenges or refer children to units that will undertake such challenges