Investigations on group allergy reactions to cefazedone in patients with penicillin allergy of the anaphylactic type (type I) and of the delayed type (type IV).

Allergological investigations (scratch test, intracutaneous test, RAST test, patch test) on 19 patients displaying allergies of type I or IV, respectively, against penicillin G according to Coombs and Gell, in the skin test with (6R,7R)-7-(2-[3,5-dichloro-4-oxo-1(4H)-pyridyl]-acetamido)-3-([(5-methyl-1,3,4-thiadiazol-2-yl)-thio]methyl)-8-oxo-5-thia-1-azabicyclo[4,2,0]oct-2-ene-2-carboxylic acid (cefazedone, Refosporen) revealed in two cases group allergy against cefazedone. The studies demonstrate that group allergic reactions against cefazedone are quite possible in patients with primary allergy to penicillin derivatives or other beta-lactam antibiotics.