Fatal methotrexate-induced pneumonitis in a psoriatic patient

Pulmonary toxicity, as an adverse effect of methotrexate (MTX) therapy, is uncommon in psoriatics. This report concerns a patient with psoriatic arthritis who developed fatal pneumonitis with a histopathological pattern of the organizing stage of diffuse alveolar damage and who was receiving MTX at a dose of 15 mg weekly for 1 month. The patient died despite the immediate withdrawal of MTX, the administration of corticosteroids, and adequate supportive care. Since MTX pneumonitis is a potentially fatal complication, new pulmonary symptoms, even in patients on low-dose MTX treatment, should be appropriately investigated.