Pulmonary Mycobacterium kansasii infection successfully treated with a regimen containing erythromycin.

Abstract

We report a case in which erythromycin was used in place of rifampicin after a severe reaction to the latter in the treatment of pulmonary Mycobacterium kansasii infection. Case reportAn 83 year old man presented with physical deterioration, weight loss, and selfneglect. There was no history ofcough or haemoptysis, or ofprevious tuberculosis. His weight was 42-8 kg and he had an intermittent low grade pyrexia. Examination otherwise showed nothing remarkable. Investigations revealed normochromic, normocytic anaemia (haemoglobin concentration 11 1 g/dl) and an erythrocyte sedimentation rate (ESR) of 103 mm in the first hour. Chest radiography showed ill defined soft tissue shadowing with cavitation affecting both upper zones, particularly on the left, and shadowing at the left base. Mantoux testing gave a negative result. Fibreoptic bronchoscopic washings and brushings contained moderate numbers ofacid fast bacilli subsequently identified as M kansasii. The organism was sensitive to rifampicin, ethambutol, erythromycin, and co-trimoxazole but resistant to streptomycin and isoniazid.Meanwhile anti-tuberculosis treatment had been started with rifampicin (450 mg), isoniazid (300 mg), and ethambutol (600 mg) daily. After two weeks' treatment he developed a hepatic reaction with vomiting, jaundice, and deranged liver function. Treatment was therefore curtailed. Reintroduction of rifampicin two weeks later, when liver function was normal, precipitated a cutaneous reaction. Treatment was therefore continued with isoniazid, ethambutol, and pyridoxine. Two weeks later, when the organism had been identified and the sensitivities were known, erythromycin stearate (500 mg thrice daily) was added.Treatment was continued for a further 11 months, which resulted in clinical improvement, as evidenced by weight gain (48-6 kg), resolution ofthe anaemia (haemoglobin concentration 13-3 g/dl), and a fall in the ESR to 15 mm in the first hour. The chest radiograph showed considerable hardening of the inflammatory shadowing and total clearing of the changes at the left base, leaving some residual thin walled cavities at both apices. Repeat bronchoscopy was not felt to be warranted.The patient remained well until six months after finishing