International Con sensus on drug allergy

Abstract

When drug reactions resembling allergy occur, they are called drug hypersensitivity reactions (DHR s) before showing the evidence of either drug‐specific antibodies or T cells.DHR s may be allergic or nonallergic in nature, with drug allergies being immunologically mediated DHR s. These reactions are typically unpredictable. They can be life‐threatening, may require or prolong hospitalization, and may necessitate changes in subsequent therapy. Both underdiagnosis (due to under‐reporting) and overdiagnosis (due to an overuse of the term ‘allergy’) are common. A definitive diagnosis of such reactions is required in order to institute adequate treatment options and proper preventive measures. Misclassification based solely on the DHR history without further testing may affect treatment options, result in adverse consequences, and lead to the use of more‐expensive or less‐effective drugs, in contrast to patients who had undergone a complete drug allergy workup. Several guidelines and/or consensus documents on general or specific drug class‐induced DHR s are available to support the medical decision process. The use of standardized systematic approaches for the diagnosis and management of DHR s carries the potential to improve outcomes and should thus be disseminated and implemented. Consequently, the I nternational C ollaboration in A sthma,A llergy and I mmunology (i CAALL), formed by the E uropean A cademy of A llergy and C linical I mmunology (EAACI), the A merican A cademy of A llergy,A sthma and I mmunology (AAAAI), the A merican C ollege of A llergy,A sthma and I mmunology (ACAAI), and the W orld A llergy O rganization (WAO), has decided to issue an I nternational CON sensus (ICON) on drug allergy. The purpose of this document is to highlight the key messages that are common to many of the existing guidelines, while critically reviewing and commenting on any differences and deficiencies of evidence, thus providing a comprehensive reference document for the diagnosis and management of DHRs.