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

Background: 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.

Methods: 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.

Results: Median age was 3 years; 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 11.5 kUA/L. Of the 278 OFCs, 225 were positive (median ED: 67.3 mg). Real-life ED was < 100 mg 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 < 100 mg (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).

Conclusion and clinical relevance: 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.