drug-induced urticaria

Last reviewed 01/2018

Non-immunological mediation:

Certain drugs may trigger degranulation of mast cells:

  • salicylates eg aspirin
  • opiates eg codeine, morphine
  • indomethacin - an NSAID
  • food preservatives eg. benzoates
  • food dyes eg tartrazines
  • atropine
  • metronidazole
  • phenytoin
  • carbimazole
  • cephalosporins
  • quinine
  • pilocarpine

Immunological mediation:

  • these may occur within seconds or minutes of drug administration if the patient has been previously sensitised (IgE type 1 hypersensitivity). Also may occur due to type 3 hypersensitivity (8-10 days after drug administration).
  • examples include:
    • sulphonamides (includes sulphonamide antibiotics, sulphonylurea antidiabetic agents, thiazide diuretics).
    • penicillins
    • serum
    • pollen vaccines

Reference:

  • Thomas RM.Drug eruptions.Medicine International 1992; 102:4273-7.