Serological and clinical characteristics of children with peanut sensitization in an Asian community.

ABSTRACT

In the past two decades, peanut allergy prevalence has increased in the West but has been perceived as having remained low in Asia. To review the clinical presentation of Asian children with peanut hypersensitivity and measure their IgE responses to major peanut allergens. We enrolled 31 children presenting with various allergies and a positive skin prick test to peanut from the Children's hospital outpatient allergy clinic in Singapore. A detailed questionnaire was completed by parents. The children's serum IgE specific to native Ara h 1, native Ara h 2, and recombinant Ara h 3 were detected using ELISA. Of the 31 patients, 19 had previously documented reactions to peanuts, while 12 had no previous clinical reaction. Most, 89.5% (17/19) of first reactions featured skin changes (urticaria, erythema, angioedema), but only 36.8% (7/19) involved skin symptoms alone. Respiratory symptoms and GI symptoms occurred in 42.1% and 26.3% of patients respectively and did not occur as the sole manifestation of reaction. The most common GI manifestation was emesis, present in 26.3% (5/19) of subjects. Two children experienced impaired consciousness with systemic, anaphylactic events. Although most sought treatment for their first peanut reaction only one patient received epinephrine. Half of our patients reported a subsequent accidental ingestion after the diagnosis of peanut allergy, with a median time from diagnosis to first accidental ingestion of 4 months and a reported increased severity of reaction in approximately half of the repeat exposures. Eighty-seven percent of children had specific IgE directed against at least one of the major peanut allergens. Among all patients, 87.1% had IgE specific to both Ara h 1 and Ara h 2 and 54.8% to rAra h 3. Asian children with peanut sensitization have clinically similar presentations and respond to the same major allergenic proteins as their Western counterparts. The perceived differences between the populations in this context do not stem from divergent clinical or immunological responses.