CLINICAL-FEATURES OF ACUTE ALLERGIC REACTIONS TO PEANUT AND TREE NUTSIN CHILDREN

Background. Peanut (PN) and tree nut (TN) allergies are potentially li fe-threatening, rarely outgrown, and appear to be increasing in preval ence. However, there is relatively little reported about the clinical features of acute reactions to these foods and their potential associa tion. Objective. To describe the clinical features of acute reactions during initial and subsequent accidental ingestions of PN and TN among children with a history of at least one acute allergic reaction to th ese foods. Design. Questionnaire survey, examination, and serologic te sting for specific IgE antibody of patients with convincing histories of acute reactions (at least one organ system involved within 60 minut es of ingestion) to PN or Results. A total of 122 patients (63% males; median age, 8 years at time of study) had acute reactions; 68 had rea ctions only to FN, 20 only to TN, and 34 to both PN and TN. Of those r eacting to TN, 34 had reactions to one, 12 to two, and 8 to three or m ore different TN, the most common being walnut, almond, and pecan. Ini tial reactions usually occurred at home (median age, 24 months for PN and 62 months for TN) and were considered to result from a first expos ure in 72% of cases. Eighty-nine percent of the reactions involved the skin (urticaria, angioedema), 52% the respiratory tract (wheezing, th roat tightness, repetitive coughing, dyspnea), and 32% the gastrointes tinal tract (vomiting, diarrhea). Two organ systems were affected in 3 1% of initial reactions, and all three in 21% of reactions. Thirty-eig ht of 190 first reactions to PN or TN were treated with epinephrine. A ccidental ingestions occurred in 55% of PN-allergic children (average of two accidents per patient with an accidental ingestion) and in 30% of TN-allergic children over a median period of 5.5 years. On average symptoms after accidental exposure were generally similar to those at initial exposure. Accidents occurred commonly in school but also at ho me and in restaurants. Modes of accidental ingestion included sharing food, hidden ingredients, cross-contamination, and school craft projec ts using peanut butter. Eighty-three percent of the children were brea stfed, with >90% of the mothers ingesting PN and at least one TN durin g lactation. Among patients reporting no history of exposure (>60% of patients for each TN), IgE antibodies were found to a particular TN in 50% to 82% of patients and to PN in 100% of patients. Conclusions. Ac ute allergic reactions to PN occur early in life. PN and TN allergic r eactions coexist in one third of PN-allergic patients, frequently occu r on first known exposure, and may be life-threatening, requiring emer gency treatment. Accidental ingestions are common, occur frequently ou tside of the home, and often require emergency treatment. Consequently , early diagnosis followed by education on avoidance and treatment mea sures (including self-administered epinephrine) is imperative.