Good prognosis, clinical features, and circumstances of peanut and tree nut reactions in children treated by a specialist allergy center

BackgroundThe diagnosis of nut allergy causes anxiety. Few studies exist that estimate risk of reactions and inform management.ObjectiveTo describe frequency and circumstances of reactions after the institution of a management plan.MethodsProspective study of children with peanut/nut allergy with an allergist's management plan. Severity and circumstances of worst reaction before diagnosis (index) and follow-up reactions were evaluated.ResultsA total of 785 children were followed for 3640 patient-years from diagnosis. Index reactions were mild in 66% (516), moderate in 29% (224), and severe in 5% (45). Fourteen percent (114/785) had follow-up reactions (3% annual incidence rate). Ninety percent had the same/reduced severity grade, and 1 of 785 (0.1%) had a severe reaction. Preschool children (n = 263) had a low incidence of reactions, and none were severe. There was a 3-fold reduction in injected epinephrine use from that used in the index reaction, required in 1 severe reaction, never twice; 14% (16/114) required no medication, 78% only oral antihistamines. Forty-eight percent reacted to the index nut type, 19% to a different nut (55% sensitized at diagnosis, 14% not sensitized, 31% not tested). Accidental versus index reactions were 4-fold more likely to be a result of contact exposure rather than ingestion. Contact reactions were always mild. Most (53%) reactions occurred at home, 5% in school, 21% at other sites (21% not recorded). The nut was given by a parent/self in 69 (61%) reactions or teacher in 5 (4%).ConclusionWith a comprehensive management plan, accidental reactions were uncommon and usually mild, most requiring little treatment; 99.8% self-treated appropriately and 100% effectively.