Drug hypersensitivity reactions (DHRs) occur in certain people and are often not predictable. DHRs can be classified as immediate and delayed reactions regarding to onset of clinical manifestations. Both reactions are considered to be an important public health problem because they can lead to life-threatening conditions; however, this review article will focus on delayed DHRs. The most important points for diagnosis of delayed DHRs are the recognition of drug hypersensitivity characteristics and culprit drug identification. While it is usually difficult to identify a culprit drug; clinical evaluation using the causality assessment method, a non-invasive process, can identify the culprit drug without the need for intensive investigation. Delayed DHRs can cause life-threatening conditions; therefore, in vivo skin tests, as well as drug provocation tests, have to be cautiously performed by a drug allergist and have not been recommended in uncontrolled conditions. ENDA/EAACI has recommended that in vitro tests (if available) be performed prior to any in vivo tests. Therefore, in vitro diagnostic tests can be alternative methods to identify a culprit drug for delayed DHR diagnosis as there is no or very low risk for patients under investigation. There are many testing approaches to identify causative agents for delayed DHRs such as: the lymphocyte transformation test (LTT), cytokine/mediator detection assays (i.e. ELISA and flow cytometry-based bead assays), multiplex bead-based immunoassay and ELISpot. The LTT is the most standardized method whereas it has been available in medical schools affiliated with university hospitals. Other in vitro tests, like cytokine detection assays, have also been used, even though they are still being evaluated. They could supplement LTT results that would provide drug allergist's with documentary evidence and prevent risk to patients by avoiding in vivo or drug provocation testing. Hence, the in vitro tests have been promising tests contributing to the management of the delayed DHR work-up process in clinical practice.

某些人会发生药物超敏反应 (DHR)，而且通常无法预测。DHR 可分为关于临床表现发作的即时反应和延迟反应。这两种反应都被认为是一个重要的公共卫生问题，因为它们可能导致危及生命的情况；然而，这篇评论文章将重点关注延迟的 DHR。诊断延迟性 DHR 最重要的一点是识别药物超敏反应特征和罪魁祸首药物。虽然通常很难确定罪魁祸首的药物；使用因果关系评估方法进行的临床评估是一种非侵入性过程，可以在无需深入调查的情况下确定罪魁祸首。延迟 DHR 可能会导致危及生命的情况；因此，体内皮肤试验以及药物激发试验必须由药物过敏症专家谨慎进行，并且不建议在不受控制的情况下进行。ENDA/EAACI 建议在任何体内试验之前进行体外试验（如果有）。因此，体外诊断测试可以成为识别延迟 DHR 诊断的罪魁祸首药物的替代方法，因为接受调查的患者没有风险或风险非常低。有许多检测方法可以确定延迟 DHR 的病原体，例如：淋巴细胞转化试验 (LTT)、细胞因子/介质检测试验（即ELISA 和基于流式细胞术的微珠测定）、多重微珠免疫测定和 ELISpot。LTT 是最标准化的方法，而它已在附属于大学医院的医学院中可用。其他体外测试，如细胞因子检测分析，也已被使用，尽管它们仍在评估中。他们可以补充 LTT 结果，为药物过敏症患者提供书面证据，并通过避免体内或药物激发测试来防止对患者的风险。因此，体外测试一直是有希望的测试，有助于管理临床实践中延迟的 DHR 工作过程。