Pneumopathy due to sulfasalazopyrine. A case with a challenge test

The complications of treatment with sulfasalazopyrine(SSP) are rare. We report a case of a 68 year old patient who was hospitalised for a hectic fever with weight loss, chest pain and dyspnoea of effort. This patient had been treated for 2 1/2 months for a haemorrhagic proctocolitis with 3 gms. per day of SSP. There was a leucocytosis of 23 700/mm3 of which there were 3,318 eosinophils/mm3. The pulmonary radiograph showed a predominantly interstitial pattern at the apices in the axillary region and in the costo-phrenic angle. The broncho alveolar lavage (LBA) was normal. A thoracic scan confirmed the interstitial syndrome and the existence of pleural thickening in the upper part of the lungs. As drug induced pulmonary disease was suspected SSP was stopped. The patient became apyrexial in 48 hours without any further treatment. Thirty days later the pulmonary radiograph and the laboratory investigations had returned to 'normal and a challenge test using the drug was given whilst the patient was still in hospital. After 24 hours there was a febrile peak of 38.7 degrees C and 36 hours later there was a leucocytosis once more of 19 700/mm3 of which there were 1,100 eosinophils/mm3. The pulmonary radiograph showed diffuse bilateral interstitial opacities. The treatment was stopped and the fever disappeared within 24 hours. After a review of the literature, two points of this case were discussed in particular: the frequency of pulmonary disease occurring as a complication of SSP and the indication for challenge test.