OBJECTIVE:To determine the safety and efficacy of 100 mg dapsone three times weekly for Pneumocystis carinii pneumonia (PCP) prophylaxis in HIV-infected, trimethoprim-sulfamethoxazole (TMP-SMX)-intolerant patients. DESIGN:Retrospective chart review of patients followed-up to 22 May 1992. SETTING:Infectious diseases outpatient clinic of a tertiary care center in suburban New York City. PATIENTS:Twenty-three HIV-infected patients requiring PCP prophylaxis with documented intolerance to TMP-SMX. MAIN OUTCOME MEASURES:Patients were followed clinically and with laboratory testing at approximately monthly intervals. RESULTS:Dapsone was discontinued in nine (39%) patients because of adverse reactions. All reactions occurred within the first 2 months of treatment. Two (14%) of the remaining 14 patients developed histologically proven PCP over 126 patient-months of follow-up. CONCLUSION:Approximately 40% of TMP-SMX-intolerant HIV-infected individuals are also intolerant of dapsone. Prophylaxis failures may be expected on a dose regimen of 100 mg dapsone three times weekly. More experience with other dose regimens and alternative agents is needed.

BACKGROUND:Lyme disease is the most common vector-borne disease in the United States. The characteristic rash, erythema migrans, is an early sign of the disease. Clinical criteria remain the "gold standard" for diagnosis at this stage of illness.OBSERVATIONS:Five (8%) of 65 patients with erythema migrans seen in a Lyme disease diagnostic center in Westchester County, New York, had a lesion with vesicles. Borrelia burgdorferi was cultured from two of five. In one case the positive culture came from a swab of the blister fluid.CONCLUSIONS:Recognition of erythema migrans and its variants is important, since early treatment of Lyme disease may prevent late complications. Vesicular erythema migrans should be added to the differential diagnosis of inflammatory vesicular rashes in the appropriate clinical setting.