[Lung involvement in pyoderma gangrenosum: a case report and review of the literature].

Pyoderma gangrenosum is a neutrophilic dermatosis that, in addition to its characteristic skin manifestations, can cause visceral alterations. Our patient was a 34-year-old woman with pyoderma gangrenosum that was exacerbated by iodine and that also affected the lungs. Other published cases of lung involvement in pyoderma gangrenosum are reviewed and we discuss the possible exacerbation of this disease by iodine. Lung involvement is the most common extracutaneous manifestation of pyoderma gangrenosum and the main differential diagnosis is then with Wegener granulomatosis. It is important to remember the possible presentation of extracutaneous manifestations of pyoderma gangrenosum, including particularly lung involvement, in order to avoid subjecting a patient to aggressive diagnostic tests, at least in the initial stages.