Thromboangiitis obliterans (TAO), also known as Buerger disease, is a nonatherosclerotic inflammatory vascular occlusive disease affecting small and medium-sized vessels, primarily of the extremities. It most commonly affects males aged 20-40 years and is markedly associated with smoking. There are reports that secondhand smoke and even smokeless tobacco use and some nicotine replacement medications also enhance the risk of TAO. Cannabis arteritis has been described in marijuana users as a subtype of thromboangiitis obliterans.

Although the number of cases in the United States has declined along with the decreased per capita rate of smoking, the incidence was estimated to be between 12 and 20 per 100 000 people in the early 2000s. The disease is most prevalent in Asia and the Far and Middle East. There is a genetic predisposition as certain human leukocyte antigen (HLA) class I and class II alleles have been associated with an increased risk of disease. Susceptible individuals seem to have an abnormal autoimmune reaction of the endothelium upon tobacco exposure. The stages of change in the vessel begin with thrombus formation in response to vascular inflammation, followed by occlusion and microabscess formation, granulomatous change, and ultimately reorganization and recanalization of the vessel. 

Affected individuals initially experience both upper and, more commonly, lower extremity claudication distally. They may also experience pain and paresthesia. It is not uncommon to affect multiple extremities, and more severe disease leads to pain at rest and ischemic ulceration that may progress to gangrene and amputation.

Superficial thrombophlebitis is also seen in TAO. Joint involvement with recurrent arthritic symptoms of the large joints can precede the occlusive phase and make early diagnosis difficult. Intestinal involvement with abdominal pain, diarrhea, and even frank melena may rarely occur. There have been rare case reports of scrotal and penile involvement.