Systemic vasculitis is a group of diseases characterized by vascular necrosis and inflammation, which can involve various blood vessels throughout the body and have a variety of clinical manifestations. The etiology of systemic vasculitis is not fully understood, but the possible causes and pathogenesis are (1) Infection Infection may be the main cause of systemic vasculitis. There is evidence that certain viral or bacterial infections of the body can lead to the development of systemic vasculitis. These pathogens include: hepatitis B virus, human immunodeficiency virus, herpes simplex virus; streptococci, Salmonella, Mycobacterium tuberculosis; fungi and certain parasites. However, not all of these pathogens can cause the development of systemic vasculitis when they infect the body, but only when these sources of infection directly damage the vessel wall or cause an abnormal immune response in the body. Zhang Chao, Department of Rheumatology and Immunology, Xinxiang Central Hospital, Henan Province, China (2) Drug and chemical factors A part of the development of systemic vasculitis seems to be related to drugs, such as penicillin and its derivatives, sulfonamides, antipyretic and analgesic drugs and iodine agents. Certain chemicals like insecticides, herbicides, snake venom serum, and various desensitizers are also associated with the development of systemic vasculitis, especially allergic vasculitis. (3) Immune factors The deposition of circulating immune complexes in the vessel wall, the close binding of certain autoantibodies to endothelial cells in the vessel wall can activate complement, fibrinolytic enzymes, kinins, neutrophils, mononuclear macrophages, platelets, etc., causing inflammatory cell aggregation and necrosis of the vessel wall, and also the formation of local thrombi leading to vascular damage. Anti-neutrophil cytoplasmic antibody (ANCA) is a recently discovered autoantibody that can react with granules in neutrophils and lysosomes in monocytes. ANCA binding to neutrophils or monocytes can activate both types of cells, and these activated cells can in turn activate inflammatory mediators, ultimately leading to the development of vasculitis. How to classify systemic vasculitis There are several different ways to classify this disease, but generally it is mostly classified according to the size of the involved vessels, namely: (1) Vasculitis involving large and medium vessels including large arteritis, temporal arteritis (giant cell arteritis) (2) Vasculitis involving medium and small vessels including nodular arteritis, Kawasaki disease, isolated central vasculitis (3) Vasculitis involving small vessels including Wegener granulomatosis, allergic granulomatous vasculitis (Churg-Strauss syndrome), microscopic polyangiitis, allergic purpura, and cutaneous leukocyte fragmentation vasculitis What is aortitis and what are its clinical manifestations Aortitis is a chronic progressive inflammation and stenosis of the aorta and its branches (involving large and medium-sized arteries), and the disease is commonly seen in young women. The inflammation of the disease involves different arteries and can present with different clinical manifestations. (1) Head and arm artery type: This type mainly involves the arteries of the head and neck and the upper extremities, including the common carotid artery, the subclavian artery, the unnamed artery and its branches, and also the aortic arch. Clinically, there is intermittent weakness of the upper extremities with pain, numbness and coldness; as well as dizziness, headache, loss of vision, memory loss and even sudden fainting. Such patients may hear vascular murmurs in the neck or supraclavicular region, present with no pulse or diminished pulse on one side, and unequal blood pressure in both upper extremities. This type most often involves the beginning of the aortic arch and is also called Takayasu disease (Takayasu). (2) Thoracoabdominal aortic type (i.e., lower extremity pulselessness) may present with numbness, coldness, pain, and easy fatigue in the lower extremities, and may present with intermittent claudication, and may be accompanied by clinical manifestations of hypertension. (3) Renal artery type Involving one or both renal arteries alone can have persistent, persistent, and severe hypertension, and the condition continues to progress eventually leading to renal failure. (4) Mixed type The lesion involves both or more of the above-mentioned groups of vessels. Most of this type has symptoms of one group first and then gradually evolves into a mixed type. All of the above types can involve the pulmonary artery and show symptoms of chest pain, shortness of breath and right heart failure. Involvement of the coronary arteries can lead to angina pectoris or myocardial infarction. What are the treatments for aortitis? In stable patients with normal sedimentation, the following can be used: (1) vasodilators: niacin 50-100mg three times a day, tolazurin 25-50mg three times a day, hexoketone cocaine 400mg three times a day, captopril 25-50mg three times a day, etc. (2) Anti-platelet aggregation drugs, including aspirin, ticlopidine (resorcinolide), etc., are mainly used to prevent more embolism of blood vessels. When the disease shows symptom progression or increased blood sedimentation, it indicates that the disease is in the active stage and mainly relies on drug treatment, including: (1) Glucocorticoids Prednisone or prednisolone 60mg/d can control the symptoms, and the dose can be gradually reduced after about 6-8 weeks, and finally maintained at 7.5~10mg/d. It should be noted that those with renal hypertension should have their blood pressure closely monitored. (2) Methotrexate (MTX) and other immunosuppressants MTX 10-25mg once a week can be used in combination with glucocorticoids to control the development of the disease, but the liver function and blood image should be monitored. (3) Symptomatic treatment such as antihypertensive drugs and drugs to improve microcirculation. Patients in remission or chronic stage with limited lesions can consider surgical treatment, such as revascularization bypass grafting, vascular anastomosis, arterial endothelial dissection, etc., which also includes angioplasty. What is giant cell arteritis Giant cell arteritis is a type of systemic, necrotizing total vasculitis that primarily involves the large and medium-sized arteries emanating from the aortic arch, especially the temporal arteries. Granulomas may form at the site of vascular inflammation and contain varying numbers of giant cells. A typical patient with giant cell arteritis has a triad of symptoms, namely temporal headache, intermittent jaw movement disorder, and blindness. What are the clinical manifestations of giant cell arteritis The disease tends to start slowly, with fever, malaise, and weight loss as common systemic symptoms. Seventy percent of patients have specific headache: one-sided or bilateral temporal headache, scalp tenderness, thickening and stiffening of superficial temporal arteries, nodularity, and pressure pain. Thirty percent of patients had symptoms of head and neck artery ischemia, which manifested as reduced vision, diplopia, ocular muscle paralysis or even blindness, as well as hearing loss, vertigo, and intermittent open mouth movement disorders. Fifteen percent of patients have manifestations of upper extremity ischemia: weak or absent pulse, unequal blood pressure in both upper extremities, and large vascular murmurs in the upper extremities. Other clinical manifestations were muscle pain and morning stiffness in the neck, shoulders, and hips, but no muscle weakness, and normal muscle enzymes and electromyography. Temporal headache, jaw movement disorder, and blindness are the typical triad of this disease. What are the diagnostic criteria for giant cell arteritis Currently, the diagnostic criteria for giant cell arteritis are: ① onset after 50 years of age; ② newly developed headache; ③ pressure pain and weakened pulsation in the temporal artery (not due to atherosclerosis); ④ sedimentation >50mm/h; ⑤ biopsy of the temporal artery shows predominantly mononuclear cell infiltration or granulomatous vasculitis, commonly with multinucleated giant cells. With the above 3 items, giant cell arteritis can be diagnosed. How to treat giant cell arteritis A small number of patients can resolve on their own after a few months or years and do not require special treatment. Most patients should be treated promptly after the diagnosis is made, and most have a good prognosis. Commonly used drugs are: (1) Glucocorticoids This disease is very sensitive to glucocorticoid therapy. Prednisone or prednisolone 20-30mg/d, the symptoms of most patients can disappear within 1 week, 1 month later gradually reduce the dose to 7.5-10mg/d, maintain 1 to 2 years, most patients can be completely relieved. In patients with relapse after stopping the drug, glucocorticoid treatment is still effective. (2) Immunosuppressants can be used as an adjunct to glucocorticosteroid treatment. (3) Other drugs such as NSAIDs can also be used as adjuvant drugs.