Cross-reactivity in HIV-infected patients switched from trimethoprim-sulfamethoxazole to dapsone.

STUDY

OBJECTIVE

To evaluate the cross-reactivity of dapsone after a documented hypersensitivity reaction to trimethoprim-sulfamethoxazole (TMP-SMX) during prophylaxis for Pneumocystis carinii pneumonia.

DESIGN

Retrospective, chart review, cohort study.

SETTING

Two university-affiliated teaching hospitals.

PATIENTS: Sixty patients infected with the human immunodeficiency virus.

MEASUREMENTS AND MAIN

RESULTS

Thirteen patients (21.7%) had cross-reactivity to dapsone after the reaction to TMP-SMX. No significant risk factors for this response were identified. Most reactions were of mild or moderate severity and rated as possibly or probably caused by one of the agents. Of the 13 patients, 4 (30.8%) continued therapy.

CONCLUSIONS

Although cross-reactivity can occur, dapsone may be considered in patients with mild hypersensitivity reactions to TMP-SMX.