Allergy in Children

The bulk of allergic disease occurs in childhood, with asthma, allergic rhinitis, eczema and food allergy comprising a significant percentage of the workload of doctors dealing with children in primary care and hospital paediatric departments. In a recent large UK survey, 20% of children were reported to have had asthma in the previous year, 18% had allergic rhino conjunctivitis (hay fever) and 16% had eczema. This represents a massive increase in prevalence compared with similar studies in the 1970s where prevalence rates were 3 fold lower. Of these children 47% had at least two co-existing conditions e.g. asthma and eczema.

Prevalence rates for food allergy have similarly increased with peanut allergy now affecting 1 in 70 children in the UK. This is reflected in a documented increase in admission rates of children with very severe (anaphylactic) reactions.

Allergic diseases are not static. The distribution and pattern of disease changes as the child matures. Infants are more likely to present with atopic eczema, food allergy, gastrointestinal symptoms and wheezing, whilst older children typically present with asthma and allergic rhinoconjunctivitis. These observed differences are frequently referred to as the allergic march, which recognises the association between these diseases and the tendency for children to “outgrow” certain aspects of their allergic disease e.g. eczema or milk allergy. Important associations are recognised between eczema and respiratory allergy, between eczema and food allergy and between rhinitis and asthma. 70% of infants with eczema are at risk of developing either asthma or allergic rhinitis.  Infants with moderately severe or severe eczema have a 30-50% risk of being food allergic.

The risk can further be quantified by the presence or absence of specific IgE (allergy antibodies) to relevant inhalant or food allergens- positive tests to house dust mite and grass pollen at 2 years strongly predicts the development of asthma and allergic rhinitis. 

It is important that doctors caring for children with allergic disease recognise these longitudinal developments. As early life events appear to be critical to the programming of an individual to develop subsequent allergic disease, the management of a child in early life may have far reaching consequences. For this reason there are a number of research programmes underway looking at early intervention strategies for the prevention of asthma and allergy.

Central to the optimum management of any child with allergic disease is an understanding of the impact of disease on their lives at school and at home and the consequences of allergic disease on their growth and development. As many children will be  multiply allergic with co-existing respiratory, gastrointestinal or skin disease, good allergy management requires a holistic, structured approach with a co-ordinated treatment strategy aimed at maximising the child’s quality of life whilst minimising the potentials side effects of treatment.