[Severe pneumonitis as a complication of low-dose methotrexate therapy in psoriasis-associated polyarthritis].

A 71-year-old woman with psoriasis-associated rheumatoid arthritis had for 15 months been treated with methotrexate (5 mg/week orally). Four weeks before admission she had developed dyspnoea and cough. On admission her axillary temperature was 38.2 degrees C, the white cell count was normal. Erythrocyte sedimentation rate (50/90 mm), lactate dehydrogenase activity (449 U/l) and the creatinine level (1.33 mg/dl) were all elevated. Blood gas analysis revealed partial respiratory impairment (pO2 52 mm Hg), and the chest X-ray demonstrated bilateral interstitial-alveolar changes. Despite antibiotics the temperature continued to rise, and on the 11th day a blood eosinophilia of 4% was noted. The bronchial mucosa was normal on bronchoscopy, and transbronchial biopsy showed only minor interstitial fibrosis, occasional macrophages and lymphocytes. Cultures of the lavage-fluid were negative. As methotrexate pneumonitis was suspected the drug was discontinued and prednisolone administered (50 mg daily for 3 days, gradually reducing over 7 days). The symptoms quickly improved, and blood gas analysis and the X-rays became normal. The patient was discharged symptom-free after 30 days.