Antibiotic Hypersensitivity: Classification, Mechanisms, Signs, and Diagnostic Approaches: A Critical Review

This review focuses on antibiotic hypersensitivity, a clinically relevant issue owing to potentially severe adverse reactions. This review describes the classification, mechanisms of occurrence, and clinical manifestations of antibiotic hypersensitivity, and the diagnostic approaches. The aim was to provide recommendations for effectively treating reactions to antibiotics.

Publications, meta-analyses, and clinical cases related to antibiotic hypersensitivity were reviewed. Four types of antibiotic hypersensitivity were identified according to the Gell and Coombs classification.

Type I [immunoglobin E (IgE)-mediated] antibiotic hypersensitivity manifests as anaphylaxis, urticaria, and bronchospasms. Type II (antibodies) causes cellular damage, resulting in thrombocytopenia or anemia. Type III antibiotic reactions are caused by immune complexes that induce inflammation. Type IV (T cells) is characterized by skin rashes or systemic symptoms. Pseudoallergies mimic allergic reactions without immune mechanisms and were separately considered. Accurate differential diagnosis is crucial in identifying true immune-mediated hypersensitivity reactions, which differ from pseudoallergic conditions, to avoid misdiagnosis and minimize patient risks associated with improper treatment or not administering necessary antibiotics. A detailed analysis of the mechanisms and clinical manifestations of antibiotic hypersensitivity allows the hypersensitivity type to be determined. Classical immunological reactions and reactions that mimic allergy but are not immune-mediated should be considered in diagnosis.

A comprehensive approach for diagnosing antibiotic hypersensitivity is required, which should include obtaining a thorough history, using modern laboratory methods (eg, skin, specific antibody, or basophil activation tests), and differentially analyzing clinical symptoms. Mimetic conditions, such as pseudoanaphylaxis or other pseudoallergic reactions that require different therapeutic approaches, must be considered as diagnoses in these cases.