Background: Skin-prick tests (SPT), food-specific immunoglobulin E level (sIgE) and clinical history have limited value individually in predicting the severity of outcome of the oral food challenge (OFC).
Objectives: To develop a score that accounts for SPT, sIgE and clinical history to predict the risk of severe reaction to the OFC.
Methods: A 5 year retrospective chart review was performed on 983 children who underwent OFC to egg, milk and peanut.
Results: Using multilogistic regression, four major indicators were found to be independently associated with failed OFC: sIgE (odds ratio = 1.04, P < 0.0001), wheal size of the SPT (OR = 1.23, P < 0.0001), a history of any prior reaction to the food (OR = 1.13, P < 0.01), and a history of a prior non-cutaneous reaction (OR = 1.99, P < 0.01); and three were independently associated with anaphylaxis: wheal size (OR = 1.16, P < 0.001), a history of a prior non-cutaneous reaction (OR = 4.24, P < 0.01), and age (OR = 1.07, P < 0.03). A Food Challenge Score (0-4) was developed which accounted for SPT wheal, sIgE, a history of a prior non-cutaneous reaction, and age. A score of 0-1 had a negative predictive value for multisystem reaction to the OFC: 95% for milk, 91% for egg and 93% for peanut. A score of 3-4 had a positive predictive value for anaphylaxis: 62% for milk, 92% for egg and 86% for peanut.
Conclusions: Severe reaction to milk, egg and peanut OFC can be predicted using a simple score that takes into account clinical data that are commonly available prior to the challenges.