Introduction to systemic sclerosis

Introduction Systemic sclerosis (SSc), also known as scleroderma, is a systemic autoimmune disease characterized by localized or diffuse skin thickening and fibrosis. The lesions are characterized by skin fibrosis and vascular onion skin-like changes, which eventually lead to skin sclerosis and vascular ischemia. The disease is characterized by localized or diffuse skin thickening and fibrosis. In addition to skin involvement, it can also affect internal organs (hearts, lungs, and digestive tracts). As an autoimmune disease, it is often associated with resistance. Nuclear antibodies, anti-centromere antibodies, autoantibodies such as anti-Scl-70. The disease is more common in women, the incidence rate is about 4 times that of men, and children are relatively rare. The basic information is also called scleroderma English name systemicscleroderma. Department of internal medicine, multiple groups of women, common symptoms, skin sclerosis, vascular ischemic infection, no cause. The exact cause of systemic sclerosis is still unclear. However, studies have shown that its pathogenesis may be related to heredity. Related to environmental factors. 1. Genetic factors Although systemic sclerosis is not inherited according to the classical Mendelian law, genetic factors are still the biggest risk factors found so far. 2. Environmental factors include drugs such as bleomycin, which can induce fibrosis, and the use of bleomycin to induce skin sclerosis in mice is sufficient to prove its pathogenicity. In addition, viral infections such as cytomegalovirus and Epstein-Barr virus are suspected to be associated with the onset of systemic sclerosis. In recent years, the role of Helicobacter pylori in the pathogenesis of systemic sclerosis has attracted much attention. Studies have shown that the positive rate of Helicobacter pylori antibodies in patients with systemic sclerosis is higher than that of normal people, suggesting that Helicobacter pylori may be involved in the pathogenesis of systemic sclerosis. . 3. Chemicals such as polyvinyl chloride, organic solvents, silicon, silica, epoxy resins, etc. are also suspected of being involved in the pathogenesis of systemic sclerosis. Classification According to the skin involvement, systemic sclerosis can be divided into: 1. Diffuse scleroderma except for the face, the distal part of the limb and the proximal end, the skin thickening also affects the trunk. 2. Localized scleroderma Skin thickening is limited to the distal end of the elbow (knee), but can affect the face and neck. 3. Scleroderma without skin sclerosis has no clinical skin thickening performance. However, there are characteristic visceral manifestations and vascular and serological abnormalities. 4. Overlap syndrome Any of the above three conditions occurs simultaneously with well-diagnosed rheumatoid arthritis, systemic lupus erythematosus, polymyositis, and/or dermatomyositis. 5. Undifferentiated connective tissue disease Renault phenomenon with clinical and/or serological features of systemic sclerosis, but no skin thickening and visceral abnormalities in systemic sclerosis. Among them, CREST syndrome refers to calcification, Raynaud's phenomenon, esophageal dyskinesia, hard fingers and telangiectasia. Clinical manifestations 1. Early symptoms The most common initial manifestations of systemic sclerosis are Raynaud's phenomenon and swelling of the extremities and face, and the skin of the fingers gradually thickens. The first symptom of some cases is Raynaud's phenomenon. Raynaud's phenomenon may precede other symptoms of scleroderma (swelling of the fingers, arthritis, visceral involvement) for 1 to 2 years or with other symptoms. Gastrointestinal dysfunction (stomach burning and difficulty swallowing) or respiratory symptoms are occasionally the first manifestations of this disease. Patients may have irregular fever, loss of appetite and weight loss before onset. 2. In almost all cases of skin, skin hardening starts from the hand. The fingers, the back of the hand are shiny and tight, the folds of the fingers disappear, the hair is sparse, and the face and neck are affected. The patient has a tight fit on the upper chest and shoulders. Lateral thick stripes can appear in front of the neck. When looking up, the patient will feel tight skin in the neck. This is rarely the case with other diseases. Facial skin involvement can be expressed as a typical scleroderma face, which is characterized by: mask face; radioactive streaks appear around the mouth, the lips are thinner, the nose is sharpened, and the mouth is restricted. The affected skin may have pigmentation or pigment loss. Skin lesions can be limited to the fingers (toes) and face, or centripetal extension, involving the upper arms, shoulders, chest, back, abdomen and legs. Some may involve the whole body skin within a few months, some gradually progress in a few years, and some progress intermittently. Clinically, skin lesions can be divided into edema stage, hardening stage and atrophic stage. The skin in edema stage is non-concave and swollen, and has a tough feeling. The skin in the hardening stage is waxy and lustrous, which is close to the subcutaneous tissue and is not easy to pinch; In the atrophic period, the superficial dermis becomes thin and brittle, and the epidermis is relaxed. 3. The bones and joints are thickened by the skin and are in close contact with the lower joints, resulting in joint contracture and limited function. Due to the fibrosis of the tendon sheath, when the affected joint is actively or passively moved, especially at the wrist, ankle, and knee, a leather-like rubbing sensation is perceived. Some patients may develop joint inflammation, and some cases may have invasive joint disease. Due to chronic chronic finger (toe) ischemia, osteolysis of the finger end can occur. X-ray films showed joint space stenosis and articular surface sclerosis. 4. The digestive tract of the digestive system is the most common visceral damage of scleroderma. Any part of the digestive tract can be affected, with esophageal involvement being the most common, followed by the anus and rectum, and the small intestine and colon. (1) Oral mouth opening is limited. After the dry syndrome, the periodontal space is widened, the gums are atrophied, and the teeth are detached. (2) impaired sphincter function in the lower esophagus esophagus can cause burning sensation and acid reflux in the sternum. Long-term can cause complications such as erosive esophagitis, hemorrhage, and lower esophageal stricture. Attenuation of the lower 2/3 esophageal peristalsis can cause difficulty swallowing and swallowing pain. Histopathology showed atrophy of esophageal smooth muscle, submucosa and lamina propria fibrosis, and the mucosa was thinned and eroded to varying degrees. The nutrient vessels of the esophagus are fibrotic. Barrett's esophagus can occur in 1/3 of patients with scleroderma, and these patients have an increased risk of complications such as adenocarcinoma. The esophageal function can be examined by esophageal manometry, barium meal imaging and gastroscope. (3) The small intestine can often cause abdominal pain, diarrhea, weight loss and malnutrition. Malnutrition is caused by slow peristalsis and excessive growth of microorganisms in intestinal fluid. It is often effective with broad-spectrum antibiotics such as tetracycline. Even pseudo-intestinal obstruction can occur. It is characterized by abdominal pain, bloating and vomiting. Similar to esophageal involvement, fibrosis and muscle atrophy are the main causes of these symptoms. Mucosal degeneration of the mucosa of the intestinal wall, after the air enters the mucosa of the intestinal wall, a cystic gas accumulation sign of the intestinal wall may occur. (4) Large intestine barium enema can be found in 10% to 50% of patients with large intestine involvement, but the clinical symptoms are often mild. Constipation, lower abdominal fullness, and occasional diarrhea may occur after involvement. Due to atrophy of the intestinal wall muscle, characteristic enteritis (diverticulum) with a large opening in the transverse colon and descending colon, such as anal sphincter involvement, may occur with rectal prolapse and fecal incontinence. Biliary cirrhosis can occur in patients with CREST syndrome. Read more...