Delayed immune mediated adverse drug reactions (IM-ADRs) are defined as reactions occurring more than 6 hours after dosing. They include heterogenous clinical phenotypes that are typically T-cell mediated reactions with distinct mechanisms across a wide spectrum of severity from benign exanthems through to life-threatening cutaneous or organ-specific diseases. For mild reactions such as benign exanthem, considerations for delabeling are similar to immediate reactions, and may include graded or single dose drug challenge with or without preceding skin or patch testing. Evaluation of challenging cases such as the patient who is on multiple drugs at the *