PEANUT ALLERGY - A REVIEW OF 132 PEDIATRIC CASES

Peanut allergy, which has become common in the United States over the last ten years, is being increasingly diagnosed in Europe, where it is now the leading cause of food allergies in children older than three years with a history of resolved egg allergy. One hundred thirty-two c ases of peanut allergy documented by a provocation test were reviewed. There were 86 boys and 46 girls, with an age range of 6 months to 15 years (male-to-female ratio, 1.8). More than half the patients were yo unger than three years at diagnosis. Atopic dermatitis was the most co mmon clinical manifestation (43.1% of cases), followed by laryngeal an gioedema (34.8 %), asthma(13.6 %), anaphylactic shock (6 %), gastroint estinal symptoms (1.5 %), and the oral syndrome (0.7%). Prick tests we re consistently positive, with a mean induration diameter of 8 mm (ran ge, 2-25 mm). The induration diameter was significantly smaller in pat ients younger than one year (mean, 4.5 mm; P < 0.01). Specific serum I gE levels were lower than 0.75 IU/ml in 16 patients (14.3 % of cases); the mean level was 30.90 IU/ml (range, 0.75-100 IU/ml). Of the eight patients with a history of anaphylactic shock, three did not undergo p rovocation testing, and the remaining five had either a labial (n = 2) or an oral (n = 3) provocation test, which was consistently positive (mean reactogenic dose, 300 mg; P < 0.001). Among the other patients, 85 (64.8 %) had a positive labial and 45 (34.3 %) a positive oral prov ocation test. The mean reactogenic dose for the oral test was 850 mg ( range, 1 mg to 7). Peanut oil produced a positive reaction in two of 5 0 (4 %) labial provocation tests and in 17 of 63 (26.9 %) oral provoca tion tests. Seventy-one (53.7 %) patients had additional food allergie s documented by provocation testing. Hypersensitivity to airborne alle rgens was found in 83 patients (62.8 %). Peanut allergy is becoming in creasingly common and currently affects 27.4% of children with food al lergies. It is occurring at increasingly younger ages, raising questio ns about the mode of sensitization. The diagnosis can be confirmed by provocation testing. Peanut allergy should be looked for routinely. Er adication of peanut from the diet is difficult because of labeling ina dequacies. An ELISA for detecting the allergen has been developed for patients with severe peanut allergy and is already available in some c ountries.