[Immediate-type reactions to pyrazole derivatives: results of skin tests and antibody determinations].

In a multicentric study by the European Study Group for Drug Allergy 58 patients suffering from an immediate type reaction after intake of pyrazol analgetics were examined with regard to allergy or pseudoallergy. Besides the scratch tests with the original substance we performed cutaneous tests with pyrazol conjugates and determined IgE and IgG antibodies by means of modified radioallergosorbent (RAST) method. Three groups could be distinguished: pseudoallergic reactions to nonsteroidal analgetics of the aspirin type (15 cases); IgE-mediated pyrazolone allergy verified by skin tests and/or IgE-RAST (21 cases), and pyrazolone idiosyncrasy (26 cases).