Nut Allergy in Children Clinical Trial
Official title:
Tree Nuts Allergies: Does a Single Nut Allergy Necessitate the Dietary Eviction?
The aim of this study is to identify, based on standardized food provocation tests, which nuts allergic patients need a selective, or a complete dietary eviction of all kind of nuts (nuts being defined as peanut, all tree nuts, pine nut and sesame). The investigators postulate that predictive factors of multiple nut allergy are high specific immunoglobulin E level, positive skin tests and/or clinical markers, such as atopic dermatitis, presence of other food allergies or a history of a severe previous reaction
Food allergy in children is a disease of growing importance, current estimation in school age
children are between 4 and 8 %. The most frequently involved foods in IgE reaction in
school-aged children are hazelnut (especially in Switzerland according to the ongoing Swiss
Registry, Wiesner et al, personal communication) and peanut. Tree nuts and peanut allergies
are often involved in severe reactions, including cases of death by anaphylaxis. In addition,
the disease is long-lasting as Fleischer et al could show that only 9% of children with nut
allergies will outgrew from it. This number is worse than for peanut where a positive outcome
is seen in 20% of the patients.
Food challenges are the most reliable tests to investigate a possible food allergy, but these
are time consuming and may elicit severe reactions in patients with a previous history of
anaphylactic reactions(8). There are no allergy tests able at this time to predict with
certainty the clinical reactivity, although Sampson et al could identify a general tree nuts
specific IgE cut-off level with a high positive predictive value for clinical reactivity.
It could be demonstrated, in well-designed studies, that in vitro cross-sensitivity between
tree nuts (members of the oleaginous family) and peanut (members of the legume family) is
frequent (86%). However, clinical reactions to tree nuts are estimated to be present in only
40% of peanut allergic patients. Therefore 60% of peanut allergic patients may eat tree nuts
without reactions.
Similarly, there is a large in vitro cross-sensitivity between tree nuts. However, it is not
known to date if this cross-sensitivity relates to clinical reactivity. Consequently, in case
of one tree nut allergy, strict eviction to all nuts is largely recommended, and possibly
results in a unnecessary dietary eviction of all tree nuts leading to a high impact on the
quality of life of the children.
We aim to identify, based on standardized food provocation tests, which nuts allergic
patients need a selective, or a complete dietary eviction of all kind of nuts (nuts being
defined as peanut, all tree nuts, pine nut and sesame). We postulate that predictive factors
of multiple nut allergy are high specific immunoglobulin E level, positive skin tests and/or
clinical markers, such as atopic dermatitis, presence of other food allergies or a history of
a severe previous reaction.
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