Generalized pustular and/or erythrodermic psoriasis may have severe or even lethal complications. A peculiar noninfectious acute respiratory distress syndrome (so-called “sterile pneumonitis”) has been described in generalized pustular psoriasis and/or erythrodermic psoriasis. We report a new case in a 14-year-old girl with a long history of pustular psoriasis and review the published work on this complication. The girl developed sterile pneumonitis during a disease flare-up, and high-dose corticosteroid therapy was quickly initiated. Within a few days, her clinical and radiological status was dramatically improved. The pathogenesis of aseptic pneumonitis is unknown, but various proinflammatory cytokines have been implicated, especially tumor necrosis factor-alpha, which could play a role in the recruitment of leukocytes to the lung. This complication has rarely been reported but should be more widely known as the differential diagnoses include congestive heart failure, acute lung infection related or unrelated to immunosuppressive therapy, and drug hypersensitivity reaction. Early recognition would avoid delays in the correct management of this potentially lethal complication, which requires high-dose systemic corticosteroid therapy.