A retrospective study of peanut and tree nut allergy: Sensitization and correlations with clinical manifestations.

Peanut (PN) and tree nut (TN) allergies are among the leading causes of fatal food-induced anaphylaxis and are increasing in prevalence, especially in children. Their cosensitization and concurrent clinical allergy have been understudied. This retrospective study investigated the correlation between PN and TN allergy, both in terms of in vitro sensitization (IVS) and clinical allergic manifestations. We conducted a retrospective medical record review at the Allergy Clinic at University Hospital of Brooklyn. Fourteen hundred six charts were reviewed, of which 76 (5.4%) had documented relevant clinical allergy: PN allergy but not TN allergy (n = 29) or TN allergy but not PN allergy (n = 11) or both (n = 30). Six patients with PN allergy but no TN exposure history were not included in the analysis. The majority of patients (67/76, 88.1%) had a concurrent history of asthma, rhinoconjunctivitis, or AD. Sensitivity of TN IVS predicting PN IVS was 38/39 (97%). Similarly, sensitivity of PN IVS predicting TN IVS was 38/42 (91%). Sensitivity of TN clinical allergy predicting PN allergy was 30/59 (51%). Sensitivity of PN clinical allergy predicting TN allergy was 30/41 (73%). The total number of organ systems involved in reported clinical reactions correlated with IVS to TN (p = 0.004) but not IVS to PN (p = 0.983). In summary, we found PN sensitization predicts TN sensitization in vitro, with lower predictability for clinical reactions.