Hand and foot cyanosis is a state of vasospasm characterized by a persistent, uniform cyanosis of the skin of the extremities, accompanied by a decrease in local skin temperature, while the pulses of the extremities are normal. The cause is not known and is characterized by symmetrical, persistent cyanosis of the skin of the hands and feet. Clinical manifestations The onset of the disease is usually around 20 years old, and it is more common in young women than in men. The symptoms tend to resolve after middle age, but some persist. The incidence is higher in patients with mental abnormalities. Patients are thin and weak, often report fear of cold around the body, continuous uniform cyanosis at the ends of the extremities, especially the hands and forearms, a marked decrease in skin temperature (cold to touch), swelling of the hands, symptoms are aggravated in the cold season, and when the limbs droop and emotional fluctuations, and alleviated in the warm season, when the hands are raised and exercise, massage of both hands and feet can reduce cyanosis or restore normal skin color, while the involvement of the feet and legs is less significant, other parts of the The skin color of other parts is normal. Local pressure may produce white spots, which fade slowly. It may be accompanied by sweaty palm surfaces, swelling, numbness, stiffness or limited pressure pain in the fingers. The skin temperature decreases, while the pulse of the affected limb is normal. Tissue nutritional changes such as ulceration or gangrene do not occur. Treatment No specific treatment is required for this disease. Reducing exposure to cold outdoor environments or protection from cold is sufficient. If necessary, vasodilators should be considered: 1) phenelzine hydrochloride and dihydroergot alkaloids; 2) ciprofloxacin orally; 3) reserpine orally; 4) calcium channel blockers, nifedipine or diltiazem depending on heart rate; 5) long-acting tolazoline; 6) scopolamine for hyperhidrosis; α1-blockers may also reduce symptoms. In severe cases, thoracic sympathetic nerve block or resection is feasible.