World Allergy Organization Systemic Allergic Reaction Grading System: Is a Modification Needed?

There is no universally accepted grading system to classify the severity of systemic allergic reactions (SARs), including anaphylaxis. Although a consensus definition for anaphylaxis was established in 2005, the signs and symptoms required to define a reaction as anaphylaxis are inconsistently applied in research and clinical practice. As a result, it is difficult to compare and evaluate safety outcomes in surveys, clinical practice and trials, and pharmacovigilance data. In 2010, the World Allergy Organization (WAO) proposed a uniform grading system to classify allergen immunotherapy SARs. The basis of the grading system is the organ system(s) involved and reaction severity. The final grade is determined by the physician/health care professional after the event is over. Although the 2010 WAO grading system was developed to classify allergen immunotherapy SARs, with appropriate modifications, it can be used to classify SARs from any cause. The purpose of this Rostrum is to present a proposed modification of the 2010 WAO SAR grading system that will make it applicable to all SARs due to any cause. The modified grading system allows for classification of less severe SARs, which may be underreported or overreported in clinical trials and surveillance studies, depending on the criteria specified for adverse event reporting. The universal use of the proposed modified SAR grading system will allow for better safety comparisons across different venues and treatment protocols.