Peanut-allergic patients in the MIRABEL survey: characteristics, allergists' dietary advice and lessons from real life.

Abstract

The MIRABEL survey is an observational study on peanut allergy in France, Belgium and Luxemburg. The objectives are to provide data on a large population, to analyse the consumer behaviour, to study the presence of peanut traces in pre-packed foods with/without precautionary allergen labelling (PAL), and to combine these data to quantify allergic risk and produce a cost/benefit analysis. This paper reports a real-life observatory of 785 patients (<16y: 86%): medical characteristics, eliciting doses (ED) in real life and in oral food challenges (OFC), factors associated with severe reactions, allergist dietary advice and patients' anxiety regarding their allergy. Age and symptoms at diagnosis, route of exposure, comorbidities, allergy tests, ED (OFC/real life; mg peanut protein), dietary advice about PAL, and anxiety score were recorded. Median age was 3years; 85% were declared allergic. Severe/potentially severe reactions were reported in 30% of the allergic patients: serious systemic reaction (15%), laryngeal angioedema (8%), shock (4%) and acute asthma (3%); 66% had atopic dermatitis, 58% asthma. Median ara h 2 sIgE level was 11.5kUA/L. Of the 278 OFCs, 225 were positive (median ED: 67.3 mg). Real-life ED was <100mg in 44.3%. Severe reactions were significantly more frequent in teenagers and adults (P=0.004), asthmatic patients (P=0.033), and patients who reacted to inhalation (P<0.001). No significant association was found for OFC ED or ara h 2 sIgE. Factors associated with strict avoidance advice including PAL were OFC ED <100mg (P<0.001), but not severe reaction history (P=0.051) or asthma (P=0.34). Anxiety was significantly associated with strict avoidance (P<0.001). Severe/potentially severe reactions, allergic comorbidities, and low EDs in real life are frequent in peanut-allergic patients. Asthma, teenage/adulthood and reaction to inhalation are associated with severe symptoms. PAL and criteria guiding dietary advice need to be improved.