[Pancytopenia during low-dose oral methotrexate therapy of psoriatic arthritis].

Pancytopenia and interstitial pneumonia occurred in a 70-year-old woman with psoriatic arthritis and compensated renal insufficiency while she was being treated with low doses of the folic-acid antagonist methotrexate (5 mg weekly). Despite the administration of platelets, red blood cells, antibiotics, acyclovir and folinic acid (100 mg daily), the pneumonia progressed, and the patient died of global respiratory failure.