Predictive values for food challenge-induced severe reactions: development of a simple food challenge score

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).

To develop a score that accounts for SPT, sIgE and clinical history to predict the risk of severe reaction to the OFC.

A 5 year retrospective chart review was performed on 983 children who underwent OFC to egg, milk and peanut.

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.

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.