ABSTRACT
Observations over the last three decades have markedly advanced the scientific study of food allergy. Studies from several centers have begun to shed light on the mechanisms of disease, clinical features of the illness, diagnostic tests, and the natural history of food hypersensitivity. We now have a better understanding of the role of food hypersensitivity in asthma. This chapter will explore the more recent studies in this discipline and offer the reader an approach that may be employed to determine the likelihood that food hypersensitivity is involved in the asthma process of any individual patient. The entire area of food hypersensitivity has recently been reviewed by Sampson in two excellent and detailed articles.1,2
PREVALENCE
How much do we really know about the prevalence of food hypersensitivity and of food hypersensitivity in asthma in particular? A
food hypersensitivity is most prevalent in young children and individuals with atopic diseases. A study of 480 consecutively born children, followed until their third birthday, found that 28% had an adverse reaction to food.4 Most of these occurred during the first year of life. However, only about 8% of the total group had adverse reactions that could be confirmed by food challenge. Almost all of these were gone by the third birthday and only a very few had associated IgE identified by skin testing. Other prospective studies from around the world suggest that about 2.5% of newborn children experience food hypersensitivity reactions to milk during the first year of life. In a Dutch study,5 it was found that about 2% of the adult population had experienced adverse food reactions. A recent random digit dial survey in the US found that about 1.1% of the population (adults and children) had experienced adverse (probably allergic) reactions to peanuts and tree nuts.6 Thus it is clear that we do not have firm numbers to assign to the prevalence of food hypersensitivity.
