ISONIAZID-INDUCED FEVER

A rare case of isoniazid (INH)-induced fever is described. A 27-year-o ld woman diagnosed with miliary tuberculosis (TB) began to receive com bined anti-TB treatment including INH, ethambutol, rifampicin and pyra zinamide on the second day of hospitalization. A spilled fever develop ed in the afternoon of the seventh hospital day. There was no evidence of a hypersensitivity reaction. All examinations including liver func tion tests, routine biochemistry tests, serum titer of antinuclear ant ibody and rheumatoid factor were within normal limits. The blood tuber culosis leukocyte count was also within normal range and no evidence o f infection at ether sites was found. Following the discontinuance of anti-TB agents, the patient's body temperature gradually returned to n ormal. When the patient was rechallenged with INH, the high fever recu rred. The fever subsided again after the discontinuance of INH, and he r recovery followed a smooth course thereafter, on combination therapy with rifampicin, ethambutol and pyrazinamide. This experience demonst rates the potential of INH to cause an isolated fever without other ma nifestations, which may be misdiagnosed as an infectious process. Thou gh it is very rare, INH-induced fever must be considered when fever de velops during anti-TB treatment.