RISK FACTORS
There appears to be a genetic component to the risk of developing a food allergy: one study found a seven-fold increase in the incidence of peanut allergy if the child has a parent or sibling with this allergy.3 Food allergy is also very much more common in children with other atopic disease such as eczema, asthma or allergic rhinitis: 33-81% of children with infantile eczema also have IgE-mediated food allergy.3
One of the most common food allergies in very young children is cows' milk allergy (CMA), which is usually non-IgE-mediated. In a study based on data from 300 practices and 1000 babies aged under 1 year with newly diagnosed CMA, the babies were seen in general practice more than 18 times over the course of a year. On average it was 4.2 visits before a food elimination diet was tried, 2.9 months before an appropriate formula was identified and 3.6 months before diagnosis.2 This typical delay in diagnosing the problem and taking appropriate action was one of the reasons that NICE felt it necessary to issue guidance on the diagnosis and assessment of food allergy, including CMA, in children and young people.