Hypersensitivity T78.4

Hypersensitivity reactions are defined according to a consensus statement of the World Allergy Organization (WAO) as objectively reproducible symptoms caused by exposure to a specific stimulus (mainly drugs = ADR) in a dose that is easily tolerated by normal subjects. Accordingly, this definition includes both allergic (mediated by specific immunological mechanisms) and non-allergic (pseudoallergy, idiosyncrasy, intolerance) reactions.

By way of example, the following clinical pictures can be classified as hypersensitivity reactions:

• Urticaria
• angioedema
• anaphylactoid reactions after application of non-steroidal anti-inflammatory drugs (acetylsalicylic acid, diclofenac, indometacin)
• maculo-papular drug reactions
• Fixed drug reaction
• Symmetrical drug related intertriginous and flexural exanthema (SDRIFE)
• AGEP
• Erythema (exsudativum) multiforme
• DRESS
• TEN