Abstract Drug hypersensitivity reactions are unpredictable
adverse drug reactions. ey manifest either within 1–6 h following drug intake (immediate reactions) with mild to life-threatening symptoms of anaphy-laxis, or several hours to days later (delayed reac-tions), primarily as exanthematous eruptions. It is not always possible to detect involvement of the immune system (allergy). Waiving diagnostic tests can result in severe reactions on renewed exposure on the one hand, and to unjusti ed treatment re-strictions on the other. With this guideline, experts from various specialist societies and institutions have formulated recommendations and an algo-rithm for the diagnosis of allergies. e key princi-ples of diagnosing allergic/hypersensitivity drug re-actions are presented. Where possible, the objective is to perform allergy diagnostics within 4 weeks–6 months following the reaction. A clinical classi ca-tion of symptoms based on the morphology and time course of the reaction is required in order to plan a diagnostic work-up. In the case of typical symptoms of a drug hypersensitivity reaction and unequivocal ndings from validated skin and/or laboratory tests,
a reaction can be attributed to a trigger with su„-cient con dence. However, skin and laboratory tests are o†en negative or insu„ciently reliable. In such cases, controlled provocation testing is required to clarify drug reactions. is method is reliable and safe when attention is paid to indications and con traindications and performed under appropriate medical supervision.
e results of the overall assess-ment are discussed with the patient and document-ed in an „allergy passport“ in order to ensure target-ed avoidance in the future and allow the use of alter-native drugs where possible.