1, skin allergic vasculitis Symptoms of vasculitis This disease only involves the skin, mostly occurs in young adults. There are usually symptoms such as weakness, joint and muscle pain, etc. A few cases may have irregular fever, but there may be no such symptoms. Skin lesions may be polymorphic, including erythema, nodules, purpura, pemphigus, hemorrhagic blisters, papules, necrosis, and ulcers. The most common lesions are below the knees, with the most frequent lesions on the lower legs and the back of the feet. More lesions begin as purpura-like papules, which do not recede when pressed, due to inflammatory cell infiltration and exudation from the vessel wall, so these bruises are high and palpable, which are characteristic of the disease. Some of them start as subcutaneous nodules, such as soybean to bean and small date size, light red with pressure pain. Some lesions begin to resemble purpura-like lesions, some lesions begin to resemble dermatitis-like changes, some resemble scleroderma-like changes, and some resemble erythema multiforme-like. The lesions may be accompanied by pimples and papules during the development of the skin lesions. Due to the severe inflammatory reaction, blood blisters, necrosis and ulcers occur on purpura and purpura papules, and ulcers with pain may occur on some nodular lesions. The edema is more severe in the ankle and dorsum of the foot. The edema is more pronounced in the afternoon and is accompanied by soreness and weakness in both lower limbs. There are various types of skin lesions, but almost all have purpura or nodules. Pustules may also appear when neutrophilic polymorphonuclear leukocytes exude into the surrounding tissue. The lesions can occur anywhere, such as the back, upper extremities, and buttocks, and are symmetrically distributed. The lesions are painful, itchy, or burning, and some are painful with no symptoms but pressure. After the lesions heal, there is pigmentation, and if there are ulcers, there may be atrophic scars after healing. In acute attacks, the lesions appear in batches, are widely distributed, are accompanied by edema in the lower legs, and are more severe. In chronic cases, recurrent attacks last for months or years. In mild cases, the lesions can heal in 2-4 weeks. In some cases, the lesions fuse with each other and expand into a large area of damage around the knees, elbows, and hands, which appears to be a persistent elevated erythema. 2, systemic vasculitis symptoms of vasculitis this disease multi-organ involvement, the disease is more serious. As the small vessels of the organs, especially the post-capillary veins, are involved, diffuse exudate and bleeding foci are mostly within the organs. Organ involvement is usually acute, with symptoms such as headache, irregular fever, malaise, malaise, joint and muscle pain. The course of the disease varies in severity and severity, and heals in about 3-4 weeks with a single exposure to the antigen, or months or years with repeated exposures. The prognosis of the disease depends on the organs involved and the extent of the lesions. 67% of patients develop polymorphic skin lesions, but palpable bruises are often the most common. 75% of patients have nonspecific fever, and about 2/3 of patients have arthralgia and joint swelling. The lesions may invade the mucous membranes and cause epistaxis, hemoptysis, and blood in the stool. Renal involvement, proteinuria and hematuria, and severe renal failure are the main causes of death in 1/3 of patients. Gastrointestinal symptoms such as abdominal pain, steatorrhea, blood in the stool, and acute cholecystitis may be present. There may be pancreatitis and diabetes mellitus. Chest X-ray shows pneumonia and nodular shadows, pleurisy or pleural effusion. The nervous system may be invaded, such as headache, diplopia, delusions, confusion, even cerebral thrombosis and paralysis, dysphagia, sensory and/or motor dysfunction. Cardiac damage is myocardial infarction, cardiac rhythm disturbances and pericarditis. Localized ischemia of the renal cortex may produce severe hypertension. The most common ocular manifestations of systemic vasculitis are outer scleral inflammation and retinal hemorrhage. Painful swelling of the parametrium and testes may be a manifestation of vasculitis. It is thought that renal biopsy and direct immunofluorescence tests are often useful in diagnosing systemic vasculitis. 3. Nodular vasculitis is a small vasculitis of the skin with a predominantly lymphocytic infiltrate. It is characterized by recurrent small skin nodules on the lower leg or foot, with a normal or slightly red surface, usually along superficial venous lines, mild pain or tenderness, and generally no systemic symptoms. The duration of the disease may vary from several weeks to several months. They occur mostly in women after 30 years of age, and occasionally in young women and men. The lesions are subcutaneous nodules to large infiltrated masses. The lesions are usually found on the lower extremities. The lesions occur on the lower extremities, especially on the back of the lower legs, but also on the thighs and upper arms. The nodules may occur on one calf only, or on one calf more than the other, often asymmetrically. The nodules have spontaneous pain or pressure, and develop slowly, but sometimes acutely, with red and hot skin on the surface. Some nodules are arranged in a linear pattern and occur in the direction of the superficial skin veins. Most of the nodules do not ulcerate and disappear in about 2-4 weeks, or they may remain as fibrous nodules and disappear slowly. The nodules often recur over a period of time. In addition to the clinical manifestations, there is no specificity in the ancillary examinations. Except for the acute phase, the blood sedimentation rarely increases, and in a few cases, the anti-“O” or Y-globulin is high. Tuberculin test and chest radiograph can determine whether the patient has pulmonary or other visceral tuberculosis. In the acute stage, anti-neutrophil cytoplasmic antibodies and circulating immune complexes in the blood are elevated. 4. connective tissue disease vasculitis systemic lupus erythematosus rheumatoid, scleroderma, dermatomyositis, leukodystrophy, dry syndrome and other connective tissue lesions involving small blood vessels, ischemic symptoms in the limb due to occlusion of small arteries in the limb, and necrosis and ulceration of the limb in severe cases. There are many types of vasculitis, and the lesions are divided into small, medium and large vessels.