MedWire News: There is a significant association between food allergy (FA) and asthma, claim researchers writing in the journal Clinical and Experimental Allergy.

Rajesh Kumar (Children’s Memorial Hospital, Chicago, USA) and colleagues report that food allergy is independently associated with asthma and that there is a dose effect, with allergies to more than one food increasing the likelihood of asthma diagnosis.

The team studied 271 children aged 6 years and over and 296 children who were under 6 years old. Asthma status and presence of food allergies were determined by parental report and by type and timing of symptoms after ingestion of a specific food, skin prick test results, and allergen-specific immunoglobulin (Ig)E levels.

The presence of at least one symptomatic food allergy was strongly associated with asthma in both the older and younger age groups (odds ratios [OR] 4.9 and 5.3, respectively). However, there was no association between asymptomatic food allergy (defined as a detectable level of specific IgE or a positive skin prick test) and asthma.

In the older group, there was a striking dose effect as the number of food allergies increased. Older children with two or more food allergies were observed to be 8.6 times more likely to have a diagnosis of asthma, compared with those with no food allergy, whereas with only one food allergy they were only 3.2 times as likely to be diagnosed with asthma. This association was less obvious in the younger group with those with just one allergy having 5.1 times greater odds for asthma and those with two or more allergies 5.8 times greater odds, compared with those with no allergies.

The risk for asthma was greatest in both older and younger children with a severe food allergy (OR=6.0 and 6.2, respectively, vs no allergy) while for non-severe allergy the odds ratios were 2.9 and 3.8 respectively.

Kumar et al also report a shorter time before first asthma symptoms in children with food allergy compared with those without.

They comment: “Our findings, if replicated by future studies, may have important clinical implications,” adding that “while it is possible that interventions to prevent or mitigate food allergy in early life could reduce the risk for asthma, more prospective studies or intervention trials are needed.”

© 2009 Current Medicine Group Ltd, a part of Springer Science+Business Media

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