ADVERSE CUTANEOUS REACTIONS TO TRIMETHOPRIM-SULFAMETHOXAZOLE IN PATIENTS WITH THE ACQUIRED-IMMUNODEFICIENCY-SYNDROME AND PNEUMOCYSTIS-CARINII PNEUMONIA

Background and Design: Patients with the acquired immunodeficiency syn drome are predisposed to cutaneous drug reactions. The reasons are poo rly understood and the circumstances in which such patients can be tre ated through hypersensitivity are a matter of discussion. We assessed the value of clinical and laboratory parameters for predicting trimeth oprim-sulfamethoxazole-induced skin reactions and the effects of conti nued trimethoprim-sulfamethoxazole therapy in such patients. We retros pectively studied all episodes of nonhypoxemic Pneumocystis carinii pn eumonia in patients with the acquired immunodeficiency syndrome who we re treated with trimethoprim-sulfamethoxazole. Results: No clinical or laboratory parameters were found to be predictive of trimethoprim-sul famethoxazole-induced cutaneous reactions. Of 38 patients treated with trimethoprim-sulfamethoxazole, 18 (47%) developed cutaneous reactions ; these occurred within a median of 11 days (range, 7 to 20 days). Of these 18 patients, 12 (67%) continued to be treated with trimethoprim- sulfamethoxazole through hypersensitivity. Trimethoprim-sulfamethoxazo le treatment was continued in 19 (95%) of the 20 patients who did not develop cutaneous reactions (P=.067). The mean duration of trimethopri m-sulfamethoxazole therapy was shorter (18 days) in patients who devel oped skin reactions than in those who did not (20 days) (P=.016). Nonc utaneous side effects accounted for all but one interruption of therap y. Conclusion: No clinical or laboratory parameters were found to be p redictive of cutaneous reactions. By treating through hypersensitivity , 67% of our patients, who otherwise might have had to stop taking tri methoprim-sulfamethoxazole, were able to continue this essential drug therapy.