Differential Diagnosis: Thromboangiitis obliterans should be differentiated from the following diseases:
1. Limb occlusive atherosclerosis: The characteristics are that both men and women can get it, usually over 45-40 years old, and there is not necessarily a smoking habit. There are signs of arteriosclerosis in other parts of the body's arteries, such as coronary arteries, renal arteries, fundus arteries, and superficial temporal arteries. A blood flow murmur may be heard at the site of large vessels, but there is no manifestation of migratory thrombophlebitis. The lesion is located in the larger arteries of the lower limbs, mostly iliac arteries, femoral arteries, and popliteal arteries, followed by posterior tibial arteries, and rarely invades upper limb arteries. Hematological examination shows elevated levels of blood cholesterol and triglycerides. X-ray examination may show calcification spots on the arteries; angiography shows irregular filling defects in the lumen, like worm erosion. The distal arteries of the obstruction can be visualized through collateral vessels, showing significant tortuosity. Pathological examination shows degeneration of the middle layer and intima of medium-sized arteries, while veins are not involved.
2. Raynaud's syndrome: It has three characteristics: most patients are young and middle-aged women; the affected areas are more common in fingers than toes and have symmetrical involvement; radial artery, ulnar artery or dorsal foot artery pulses are normal.