Limb ulcers are an important complication of systemic scleroderma, and persistent and recurrent ulcers can cause severe pain, infection, gangrene, functional impairment, and decreased quality of life, causing great suffering to patients. Because of this, the study of scleroderma extremity ulcers has become a hot issue for research in recent years. The main pathological changes of SSc are inflammatory cell infiltration of connective tissue, intimal hyperplasia, vascular occlusion, fibrous tissue proliferation and sclerotic atrophy. In the initial stage of skin lesions (inflammatory phase), interstitial edema of the dermis, separation of collagen fibers, perivascular lymphocytic infiltration of small vessels, edema of the vessel wall, and breakage of elastic fibers. Thereafter, the perivascular inflammatory cell infiltrate subsides, collagen swells, and acidic mucopolysaccharides and their collagen increase around the small vessel fibers. In the later stage (sclerotic phase), collagen fibers homogenize, collagen fiber bundles parallel to the epidermis increase, and collagen fibers proliferate and extend deeper. Small vessel walls thicken and the lumen becomes smaller to the point of occlusion. Late stage changes continue to occur, leading to epidermal and appendage atrophy, calcium salt deposition, fascial muscle sclerosis and atrophy, etc. 1.Symptom examination Early swelling of hands and fingers may also involve forearms, feet, lower limbs and face, but lower limbs are less involved. The swelling period may last for weeks, months, or even longer. The edema is concave or nonconcave and may be accompanied by erythema. The skin lesions begin at the distal end of the limb and progress to the proximal end. The skin gradually hardens, thickens, and finally clings to the subcutaneous tissue (sclerotic phase). 2.Blood routine Blood routine is the most general and basic blood test. Routine blood tests are usually taken from peripheral blood for examination, such as blood from fingertips and earlobe areas. After passing through the blood cell analysis instrument, the computer reports the results, and this item has become a practice to examine patients. Blood consists of two major parts, liquid and tangible cells, and routine blood tests are performed on the cellular part of the blood. Blood has three different functions of cells – red blood cells (commonly known as red blood cells), white blood cells (commonly known as white blood cells), and platelets. Diseases are determined by observing changes in number and morphological distribution. It is one of the common auxiliary tests used by doctors to diagnose the condition.