Clinical features and respiratory comorbidity in Hong Kong children with peanut allergy

Food allergy is more common in infants and children (~6% under 3 years of age) than in adolescents and adults (~3.5%). 1 The epidemiology of food allergy is influenced by cultural and geographical dietary influences. In US studies of young children, cow's milk, hen's egg, peanut, wheat, and soybean account for the majority of significant food-allergic reactions. For adults, peanut, tree nuts (e.g. walnut, Brazil nut, cashew), fish, and shellfish account for the majority of significant reactions. 2 Food allergic reactions can be severe and life-threatening, and a number of patient factors were reported to predict anaphylaxis. 3 Such potentially fatal reactions can occur at any age and even on the first known exposure to a food. Food allergy is partly Abstract Peanut is commonly associated with severe and potentially life-threatening allergic reactions. Besides, such patients had increased risk of developing asthma. Recent data suggested peanut allergy to be uncommon in Asian children. We reviewed clinical features of peanut allergy among 58 children who were managed in our allergy clinic between January 1999 and June 2012. Their median age was 5.4 years (range 0.8-17.6 years), and 43 (74.1%) were males. They presented at a median age of 2.0 years (range 0.3-10 years). Nineteen (32.8%) patients suffered from peanut-induced anaphylaxis. Thirtyseven (63.8%) patients reported isolated cutaneous symptoms. Male patients more likely presented with anaphylaxis than females (41.9% vs 7.1%, P=0.012). Thirty-three patients showed allergic reactions to other foods, the leading ones being hen's egg (27.6%), shellfish (17.2%) and tree nuts (13.8%). Nearly 90% of these patients were atopic to at least one allergen by skin prick testing. Concerning respiratory comorbidity, asthma and rhinitis were found in 35 (60.3%) and 37 (63.8%) patients respectively. Asthma was associated with presence of rhinitis (P=0.009) and marginally with being born outside Hong Kong (P=0.056). Regarding anti-allergy treatments, adrenaline autoinjectors were prescribed to 17 (29.3%) patients whereas salbutamol inhaler and oral antihistamine were prescribed to 29 (50.0%) and 46 (79.3%) patients respectively. In conclusion, this case series reveals that anaphylaxis is common among local children with peanut allergy. Such finding strongly supports that adrenaline autoinjectors should be an essential component of their management plan. The majority of these peanut-allergic children also suffer from airway allergies.