Milk-induced wheezing in children with asthma
Food allergy has been gaining increasing attention, mostly as causing gastrointestinal and cutaneous reactions. Its role in asthma seems to be under-recognised.This study's aim is to explore the frequency of involvement of a common food, namely cow's milk, in childhood asthma.32 children (5 months to 11 years; median 24 months; mean 34 months) with asthma and a suspected history of cow's milk allergy were studied. They underwent skin prick testing (SPT) and specific IgE (sIgE) testing to whole cow's milk (WCM), casein, α-lactalbumin, and β-lactoglobulin, followed by single-blind oral milk challenge.Reactions to milk challenge occurred in 12 (37.5%) including wheezing in 5 (41.7%, or 15.6% of the whole group). Children who developed wheezing at the time of challenge were younger than those who had negative challenge (23.0 months vs. 34.8 months). Challenge was positive in 33.3% of subjects who had a positive SPT, and SPT was positive in 50% of challenge-positive subjects. Regarding sIgE, challenge was positive in 26.7% of sIgE-positive subjects, and sIgE was positive in 33.3% of challenge positive subjects. Skin or serum testing with individual protein fractions did not seem to add significant advantage over testing with WCM alone.This study shows that cow's milk can cause wheezing in children with asthma. Although SPT seemed to be more reliable than sIgE testing, both had suboptimal reliability. It is worth considering possible milk allergy in children with asthma, particularly when poorly controlled in spite of proper routine management.