Abstract
Seven patients with allergic reactions to cephalothin were studied. Four of these occurred in 51 consecutive patients receiving cephalothin. The majority of the patients with cephalothin reactions had a previous history of penicillin allergy and were found to have positive skin tests with penicilloyl-polylysine (PPL). Allergic reactions to cephalothin occurred at a higher rate in Negro women than in Negro men or white persons. A history of atoplc disease was more common in patients with allergic reactions to cephalothin than in persons given cephalothin without reactions. Cephalothin must be used with caution in the treatment of patients with a history of allergic reactions to penicillin or with positive skin tests to PPL, and cannot be considered as a uniformly salt substitute for penicillin in such patients.