Ciprofloxacin is a broad-spectrum antibiotic of the fluoroquinolone family. Anaphylactoid reactions occur at a reported rate of 1.2/1000 prescriptions [1]. Many of these reactions [2] occur in patients positive for the human immunodeficiency virus (HIV). We describe a 21-year-old white woman negative for HIV infection who had anaphylactoid reactions after initial and repeated encounters with ciprofloxacin. Thirty minutes after receiving ciprofloxacin for pelvic inflammatory disease, the patient presented to the emergency department reporting generalized itching, shortness of breath, facial swelling, and hives. She had received ciprofloxacin, meperidine, and ranitidine 2 weeks earlier for pelvic inflammatory disease and had a similar but milder reaction on that occasion. On this current presentation, she was receiving ciprofloxacin only. She stated that she had allergies to penicillin and aspirin.

Physical examination showed a urticarial rash with facial angioedema. She was normotensive with tachypnea and tachycardia; her chest was clear. Treatment included oxygen, intravenous hydrocortisone, cimetidine, diphenhydramine, and subcutaneous epinephrine. An admission leukocyte count was 17 100 cells/mm³. Results from other laboratory tests were not remarkable. Antibody tests for HIV were negative at admission and after repeated testing 3 months later. The patient recovered quickly and was released in the morning at her request.

Despite the generalized availability of ciprofloxacin, few reports have associated anaphylactoid reactions with its use. Only 29 cases of anaphylactoid reactions, including the current one, have been reported [1-3]. Twelve of these patients were known to be HIV positive. The HIV status of the other 17 patients was unknown. In these 29 reported cases, 17 patients had the anaphylactoid reaction with the initial dose of the drug [1, 4].

This is only the second report confirming an anaphylactoid reaction in a patient who was known to be negative for HIV [2]. Recently, the Centers for Disease Control and Prevention [5] recommended an expanded indication for ciprofloxacin as a convenient single-dose oral agent for the treatment of gonorrhea. Because this group of patients is also more likely to be HIV positive, physicians need to be aware of the potential for anaphylactoid reactions with ciprofloxacin.