allergic

Last reviewed 01/2018

Urticarias which are truly allergic in origin may include:

  • type I mediated - tissue fixing IgE is produced in response to specific allergens:
    • food - eg. shellfish, strawberries, nuts
    • drug - eg. penicillin, sulphonamides
    • infestations - eg. parasitic worms, scabies
    • infections - eg. candidiasis

  • type III mediated - immune complexes are deposited in skin vessels and cause wheals of longer duration often associated with arthralgia and fever:
    • serum sickness
    • Henoch Schonlein purpura