Food protein-induced enterocolitis syndrome to peanut with early introduction: a clinical dilemma

The Learning Early About Peanut Allergy (LEAP) study and Addendum Guidelines for the Prevention of Peanut Allergy spurred a dramatic shift in the approach to peanut introduction in early childhood.1,2 Recommendations now encourage peanut introduction to infants as early as 4 to 6 months to reduce the risk of developing peanut allergy. Patient 1 was an 11-month-old male with moderate atopic dermatitis who previously had specific IgE (sIgE) and skin prick testing (SPT) at 6 months that showed sensitization to peanut, tree nuts, egg, and milk, none of which had been introduced. Other clinical features include diarrhea, lethargy, pallor, cyanosis, hypotension, and hypothermia.3 Symptom onset is often correlated with timing of food introduction.3 Although cow's milk and soy are the most common triggers during food introduction in infants, FPIES can be triggered by solid foods traditionally thought to be of low allergenicity. Table I Clinical features of children with FPIES reactions to peanut FPIES, Food protein-induced enterocolitis syndrome; OFC, oral food challenge; SPT, skin prick testing. 1 2 3 Sex M F F Age at peanut introduction (mo) 13 5 4 Age at peanut reaction(mo) 13∗17∗ 6∗7∗ 9†47† Quantity of peanut ingested 1 g1 g 1 g100 mg Unknown>1 g Reaction symptoms Repetitive emesis 1.5 h after ingestion, pallor, perioral cyanosis (13 mo)Emesis x1 2.5 hours after ingestion (17 mo) Repetitive emesis 2.5 h after ingestion, lethargy, diarrhea Repetitive emesis 4.5 h after ingestion, pallor, lethargy Age at testing (mo) 1114 6 1346 SPT (wheal, mm) 0 (11 mo)0 (14 mo) 3 N/A sIgE peanut (kU/L) (age) 4.61 (6 mo)2.76 (11 mo)2.37 (14 mo) 1.88 (6 mo) 4.10 (13 mo)0.58 (46 mo) Peanut component testing (kU/L) Ara h 1 0.39 (11 mo)/0.86 (14 mo)