Epidemics of vascular toxicity and pulmonary hypertension: what can be learned?

Epidemics of vascular disease caused by toxins and infectious agents affect ing both humans and animals have been common in history. Examples of agents implicated include anorexients, ergotamine, mercury, arsenic, vinyl chlori de, thorotrast, plant alkaloids, nitrites, toxic oil, tryptophan and bacter ial, viral and parasitic infections. A major characteristic of these disord ers is endothelial dysfunction, which may manifest itself in vasospastic di sorders, sclerodermiform skin lesions, fibrosis, osteolytic lesions, polyne uropathy and portal and pulmonary hypertension. Angiosarcoma may also be a late outcome. These diseases are more common than is generally appreciated. The aetiology is usually multifactorial. This and other factors contribute to delayed recognition.