Drug-induced pneumonitis caused by sulfamethoxazole, trimethoprim during treatment of Pneumocystis carinii pneumonia in a patient with refractory ulcerative colitis.

We recently treated a patient with intractable ulcerative colitis complicated with Pneumocystis carinii pneumonia in whom sulfamethoxazole/trimethoprim caused pneumonitis. The pneumonitis was difficult to differentiate from worsening of the infection or the appearance of another opportunistic infection. The patient's history of sulfasalazine (sulfonamide)-induced pneumonitis made diagnosis possible. The CD4/CD8 ratio of lymphocyte subsets in bronchoalveolar lavage fluid was decreased at the diagnosis of Pneumocystis carinii pneumonia and this ratio had increased when drug-induced pneumonitis was diagnosed. Topical administration of beclomethasone dipropionate by enema was a safe and effective for the treatment of such a compromised patient with active colitis.