Drug allergy: diagnosis and management ( NICE guidance summary )

The tables offer a comprehensive overview of the signs and allergic patterns associated with suspected drug allergies, categorizing reactions based on their timing of onset. These include immediate reactions, such as anaphylaxis and urticaria, and non-immediate reactions, which may or may not involve systemic involvement. While focusing on common and significant features of drug allergies, the tables also acknowledge the existence of other potential presentations, highlighting the diverse and complex nature of allergic responses to medications.

Immediate, rapidly evolving reactions

Non-immediate reactions without systemic involvement refer to allergic responses to medications that appear after the initial exposure period, typically manifesting on the skin without affecting the whole body. These reactions, such as exanthema (widespread red macules or papules) and fixed drug eruption (localized inflamed skin), generally occur 6 to 10 days after first exposure or within a few days of re-exposure. Unlike immediate reactions, they are delayed and primarily localized, not typically accompanied by systemic symptoms like fever or anaphylaxis.