Lupus-like syndrome

Introduction to lupus-like syndrome The syndrome is a syndrome similar to lupus erythematosus caused by long-term treatment of non-rheumatic primary disease with certain drugs, and belongs to iatrogenic diseases. Clinically, it is characterized by systemic lupus erythematosus such as fever, joint symptoms, heart damage and skin lesions, but it is different from systemic lupus erythematosus. After stopping the pathogenic drugs, most patients' symptoms and objective signs can be Relieved quickly. basic knowledge The proportion of illness: 0.002% Susceptible people: no special people Mode of infection: non-infectious Complications: thrombophlebitis

Cause of lupus-like syndrome

Genetic factors (35%):

Today, the pathogenesis of idiopathic systemic lupus erythematosus has not yet been fully clarified. To clarify the pathogenesis of drug-induced lupus-like syndrome is a very difficult and complicated problem. It was first discovered that there are musculoskeletal members in the family members of this syndrome. Systemic diseases, and many family members have serological abnormalities. The fact that these patients continue to exist after stopping the drug also indicates that they have a natural tendency to develop lupus, but this theory has not been widely Admit.

Disease factors (35%):

Through the study of procainamide-induced syndrome, these patients were negative before the administration of the drug, whether it was LE cells or other serological reactions, but turned positive during the course of the drug, ANA negative before the drug, with Plu After carcinamide was observed, about 50% of ANA became positive after 2 to 18 months of treatment, and some of them developed symptoms of mild lupus erythematosus, which indicates that this syndrome has nothing to do with the so-called lupus quality. Lupus-like changes caused by procainamide.

Drug factors (30%):

From the perspective of various drugs causing this syndrome, there is no chemical or pharmacological common feature between them, but other drugs except penicillin require large doses and long-term use (at least 2 months). Can cause this syndrome.

Pathogenesis

Excessive total dose of the drug may also be a causative factor. Currently, the mechanisms by which various drugs cause the syndrome can be divided into four categories:

1. The individual is allergic to the drug. In the case of hydralazine, it is found that the patient can undergo an allergic reaction to the drug, that is, the circulating antibody can be confirmed from the patient's body, and the patient's lymphocytes can be added in an in vitro test. When hydralazine is proliferated, when the drug metabolism is delayed, the time of exposure to the drug in the body environment is inevitably prolonged, and it is more likely to cause allergic reaction. In addition, the drug affecting acetyltransferase, in addition to isoniazid, sulfamethazine, There are hydralazines, even if a small amount of application can delay the formation of anti-nuclear antibodies (ANA) and lupus-like syndrome. However, if long-term use of drugs, regardless of whether acetylation is delayed, the opportunity for anti-nuclear antibodies There is no obvious difference.

2. The fact that the formation of a drug complex causes DNA denaturation and formation of an antigen hydralazine to form a complex with soluble DNA and alter the antigenic properties of the latter has been confirmed, but the antigenicity of the drug-DNA complex is in vitro. It has not been confirmed that other stabilizer-DNA complexes have been artificially produced. For example, chlorpromazine-single-stranded DNA complexes can be formed under long-wave ultraviolet irradiation, and procainamide-DNA complexes can be formed under the action of oxidants. However, there is no evidence that the antigenicity of these complexes is increased.

Lupus-like syndrome prevention

Controlling the total dose of the drug during the treatment of the disease is the key to preventing this syndrome. Once the diagnosis of this syndrome is confirmed, the immediate withdrawal of the pathogenic drug or the switch to other drugs is the most effective measure to prevent the continued development of this syndrome. The prognosis of this syndrome is good, and it can be restored to normal with withdrawal. There are few sequelae. However, once again, the disease can be induced again. It must be noted that individual patients need long-term treatment with hormones. This may be drug-induced. The syndrome has been converted to idiopathic SLE.

Lupus-like syndrome complications Complications thrombophlebitis

In addition to drug-induced lupus-like syndrome, drugs can induce other rheumatoid diseases, such as penicillamine can induce scleroderma, rheumatoid arthritis, penicillin can induce polymyositis, phenytoin can induce lupus-crust The disease-like overlap syndrome, some drugs can induce nodular polyarteritis-like syndrome. Joint cavity fluid can sometimes occur. It can also be accompanied by varying degrees of peritonitis and ascites. It can also be accompanied by Raynaud's phenomenon, Sjogren's syndrome, subcutaneous nodules, and thoracic thrombophlebitis.

Symptoms of lupus-like syndrome Common symptoms Inability to fatigue Joint pain Liver splenomegaly Chest pain Breathing erythema rash rash Insomnia Breath sounds weakened anorexia

1. Fever: About half of the cases have different degrees of fever, sometimes fever can be its main clinical symptoms, fever can be its early manifestations, followed by other symptoms, but also with other symptoms.

2. Joint symptoms: related to joint pain, arthritis, joints of the extremities can be affected, characterized by symmetry, multiple, sometimes joint fluid accumulation can occur.

3. Myalgia or co-existing with joint symptoms, or appear alone, can be seen in any part of the body muscles, but the limbs and trunk muscle pain is obvious.

4. Serositis: multiple, can involve the pericardium and pleura, may also be associated with varying degrees of peritonitis and ascites, serositis usually occurs after joint pain, bilateral chest pain, cough, hemoptysis and dyspnea Pulmonary auscultation can be found that unilateral or bilateral breath sounds are weakened, sometimes pleural friction sounds can occur, and pericardial rubbing sounds can be heard when pericarditis is present.

5. Skin lesions: can be characterized by pleomorphic exudative erythema, urticaria, urticaria-like rash, purpura, nodular vasculitis, angioedema, subarachnoid hemorrhage, gangrene caused by perivascular embolism, etc. But there are few typical butterfly erythema.

Examination of lupus-like syndrome

1. About 20% of blood routine and erythrocyte sedimentation rate have anemia, 30% of cases have leukopenia, platelets are mostly low, and erythrocyte sedimentation rate increases in most cases.

2. A small number of cases of urine can show mild proteinuria, tubular urine and microscopic hematuria. Among them, one of them can be one of them, and two or all of them are positive.

3. There are no abnormalities in biochemical tests, and only some cases have elevated gamma globulin.

Diagnosis and identification of lupus-like syndrome

1. Drug rash: In particular, serum-like reactions, often manifested by rash, joint pain and respiratory symptoms, and more abnormal urine tests. However, the ANA, RF, ESR, LE cells, and Coomb tests were all negative.

2. Idiopathic systemic lupus erythematosus: The biggest difference with this syndrome is that the symptoms can be relieved quickly after stopping the syndrome. The central nervous system and kidneys are less affected, even if they are involved, the typical butterfly shape The erythema, Raynaud's phenomenon, lymph node enlargement, splenomegaly incidence, total complement (CH50) and C3 levels were normal.

3. Septicemia: effective for antibiotic treatment, bacterial culture is more positive, and ANA and RF are negative.

4. Tuberculosis: Extrapulmonary tuberculosis sometimes can not find a lesion, manifested as fever, may have rash and joint symptoms, ESR increased, but more tuberculin test positive, anti-tuberculosis treatment is effective. The ANA, RF, and LE cells were negative, and the symptoms could not be alleviated after the suspicious pathogenic drugs were stopped again.

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