Pneumonitis complicating methotrexate therapy for pustular psoriasis

We report a patient with pustular psoriasis who developed interstitial pneu monitis after receiving weekly methotrexate (MTX) therapy at an average dos e of 20 mg for 26 years. The patient responded dramatically to withdrawal o f the drug and administration of corticosteroids. Pulmonary toxicity is a r are adverse effect of MTX therapy and is particularly uncommon in psoriatic s. As interstitial pneumonitis is a potentially fatal but reversible compli cation, early respiratory symptoms even in patients on low-dose MTX treatme nt should be appropriately investigated.