Chinthrajah RS, et al. - A predictive algorithm of a food challenge severity score (CSS) was developed for the detection of subjects at higher risk for severe reactions to a standardized peanut oral food challenge (OFC). On the basis of cumulative tolerated dose and a “severity clinical indicator”, reactions were assigned a CSS between 1 to 6. A multi-step analysis was performed taking into account demographic characteristics, clinical features, peanut component IgE values, and a basophil activation marker in order to derive a flexible decision rule to understand risk during peanut of OFC. The CSS was recognized as a novel tool that integrates dose thresholds and allergic reactions to understand risks associated with peanut OFCs. Lab-values (CD63 ratio), along with clinical variables (exercise-induced asthma and forced expiratory volume in 1 sec/forced vital capacity ratio) were identified as contributors to the predictive ability of the severity of reaction to peanut OFC.