Anaphylactoid reactions due to nonsteroidal antiinflammatory drugs: clinical and cross-reactivity studies.

Background: Anaphylactoid reactions due to nonsteroidal antiinflammatory drugs have been described.

Objective: To study the clinical characteristics of 21 patients with anaphylactoid reactions due to nonsteroidal antiinflammatory drugs and to determine the cross-reactivity to non-steroidal antiinflammatory drugs not involved in the previous reactions nor structurally related by means of single-blind, placebo-controlled drug challenges.

Patients And Methods: Twenty-one patients who exhibited clinical evidence of anaphylactoid reactions after nonsteroidal antiinflammatory drugs were recruited for the study at the time of admission in Emergency Unit of our Hospital, Single-blind, placebo controlled oral challenges with nonsteroidal antiinflammatory drugs (except those reported by the patient as being responsible for the previous reaction), were performed in all patients.