THE OCCURRENCE rate of anaphylactoid reactions to penicillin is in the thousands each year, and the mortality rate is estimated to be about 10 per cent.1 In the development of newer forms of penicillin, one of the primary interests has been the possibility of finding one that would not produce allergic reactions, especially in those already showing sensitivity to the older forms. Inasmuch as penicillin is not very antigenic in animals and information regarding antibodies from in vitro studies is scanty, knowledge of the characteristics of anaphylactoid penicillin allergy is secured only from clinical reports. The following cases are reported because of positive reactions to penicillin G (benzyl penicillin), with negative skin tests, and tolerance to full doses of sodium methicillin (Staphcillin), given intramuscularly.
Report of Cases
A 31-year-old male laborer was admitted to Kennedy VA Hospital on Nov. 13, 1960 because of an acute hallucinosis
Luton EF. Methicillin Tolerance After Anaphylactoid Reactions to Penicillin G. JAMA. 1961;177(2):152-153. doi:10.1001/jama.1961.73040280019016b