Today, about one in four European children suffer from allergy, which makes this disease the non-infectious epidemic of the 21st century. Evidence suggests that lifestyle factors and nutritional patterns, such as breastfeeding, help to reduce the early symptoms of allergy.
The detection and reduction of the early causes of childhood allergy is the major topic at the 2nd EAACI Pediatric Allergy and Asthma Meeting (PAAM 2011) in Barcelona. There is no doubt that the exposure to allergens, both in food and the environment, play a role though the exact significance of dose and timing is not yet fully defined. According to Prof. Halken, PAAM 2011 Chair "there are some hypotheses suggesting that specific lifestyle and nutritional patterns may lead to early symptoms of allergy. For example, breastfeeding for the first 4-6 months has been showed to reduce the risk for atopic eczema and cow's milk protein allergy".
The development of allergy is a result of a complex interaction between genetic and many environmental factors that may protect against or promote its development. Factors such as pollution have also been linked to the increased prevalence of allergic diseases during childhood in developed countries.
"Exposure to many environmental factors have changed during the last decades, including exposure to tobacco smoke, which appears to increase the risk for airway infections and asthma. Besides, exposure to allergy developing agents such as food, house dust mites, pets and pollens is a prerequisite for development of allergic diseases, but also many other unknown factors may play a role", explains Prof. Halken.
"Genetic factors may also influence the susceptibility to different environmental factors and also influences the pattern of symptoms of the individual child", says Prof. Halken. "Some studies report that a child with atopic dermatitis and a family background show higher risk to develop asthma later in life. When one of the parents is allergic, the child is predisposed to be allergic, and the risk is even higher when both parents suffer this disease".
The expression of allergic disease may vary with age, and some symptoms may disappear being replaced by other symptoms. As Prof. Halken says, "infants typically experience atopic dermatitis, gastrointestinal symptoms and recurrent wheezing, whereas bronchial asthma and allergic rhinoconjunctivitis are the main allergic symptoms in childhood". In that sense, allergic reactions to foods, mainly cow's milk protein, are the commonest manifestation in the first years of life, whereas allergy to inhalant agents mostly occurs later in childhood.
Physicians agree that one of the key elements in achieving better management of childhood allergy is to improve diagnostic techniques and to develop treatments that do not only reduce symptoms, but can induce a permanent cure. "Early diagnosis can lead to effective treatment to reduce symptoms and improve quality of life. Knowledge about allergies can help patients to avoid contact with offending agents, and thereby to reduce symptoms and avoid risky situations, which may even be life threatening", points out Prof. Halken.