We report 3 cases of rash after the first dose of antituberculosis polytherapy, thus raising questions concerning the procedures to be followed.
Case report: Three patients developed a pruritic rash 1 hour after the first dose of isoniazide, rifampicine, pyrazinamide and ethambutol given simultaneously. The eruption did not recur after readministration of isoniazide and rifampicine successively. Pyrazinamide, which was readministered last (at the full dose in one case and at progressive doses in the two others), induced a recurrence in two of them. Pyrazinamide was definitively withdrawn in one patient with recurrence and slower pyrazinamide readministration allowed continuation of treatment in the other two patients.
Conclusion: Since pyrazinamide appeared to be responsible for rash following the first administration of antituberculosis polytherapy, a protocol for readministration of the 4 drugs is suggested. If the responsibility of pyrazinamide is confirmed it should be readministered very slowly.