Management of sulfadiazine allergy in patients with acquired immunodeficiency syndrome

AR to sulfonamides are frequent in patients suffering from AIDS. ARs are sometimes so severe that suspension of treatment is required. ’ Because of the therapeutic alternative failure or lack of treatment, we are confronted with a situation of vital risk to the patient, since drug desensitization is necessary.2‘4 We report seven patients with AIDS with previous serious ARs to SZ. 01s requiring its use are presented in Table I. In all patients, the symptoms disappeared after SZ was stopped. An alternative treatment was tried without any improvement in the 01. Skin prick tests, performed with a solution of SZ (Sulfadiacina; Andreu Laboratory SA, Barcelona, Spain) in normal saline to concentrations of 1, 2 and 5 mg/ml were negative in all patients. Histamine release tests (with an automated fluorometric method) were negative in the four cases tested (1, 2, 3, and 4). A single-blind placebo COC was performed, with progressively increasing doses administered of SZ, starting with 62.5 mg. If no symptoms were experienced, the close was increased twofold at 24-hour intervals until the therapeutic dose was reached of 100 mg / kg / day or until recurrence of symptoms. This test was positive in the three patients. Patient 1 demonstrated general macular rash and fever. Patient 2 had a general macular rash, fever, and facial angioedema. Patient 3 only presented a general macular rash. Single doses and time when the patients reacted were 500 mg, 2 hours; 125 mg, 4 hours; 125 mg, 30 minutes, respectively. We did not consider this test appropriate for patient 4 because he had previously been treated on two separate occasions with therapeutic doses of SZ with the