[Skin testing with the components of analgesics in patients with anaphylactoid hypersensitivity reactions to mild analgesics].

In 282 patients presenting with adverse reactions to mild analgesics, prick tests were performed with components of analgesic drugs; in some of them, commercial preparations were also tested. In 19 patients (7%), a total of 40 conclusively positive immediate reactions was found: there were 22 reactions to pyrazolone derivatives, 14 reactions to commercial preparations, and one singular reaction to phenacetin, phenobarbital, carbromal and vitamin B1, respectively. Cross-sensitivity to different pyrazolone derivatives was observed in only 5 of 15 patients with a positive reaction to at least one of these substances. One of the patients with a positive immediate reaction and 2 further individuals developed positive test reactions after 4 to 24 h. Within 117 patients who gave a clear-cut history of anaphylactoid reactions to mild analgesics, there were conclusive immediate prick test results in 15 cases (13%). In these patients, the diagnostic relevance of the prick test increased with the severity of symptoms in the history, and a conclusive immediate reaction was obtained in 25% of those with full shock in the history.