Overview of mesenteric lymph node tuberculosis
Tuberculosis of the mesenteric lymph nodes, also known as tuberculous mesenteric lymphadenitis, is caused by infection with Mycobacterium tuberculosis. It can be primary or secondary to tuberculosis infection in other parts of the body. It occurs mostly in children and is mainly characterized by intermittent abdominal pain and diarrhea, which can lead to malnutrition and intestinal adhesions. Systematic anti-tuberculosis treatment is effective.
Causes
Mycobacterium tuberculosis infection can cause mesenteric lymph node tuberculosis. This disease is common in children and adolescents, divided into primary and secondary, primary often due to drinking milk or dairy products contaminated with tuberculosis bacilli; secondary is more common than primary, mostly secondary to open pulmonary tuberculosis or intestinal tuberculosis. Tuberculous peritonitis can be caused by rupture of the diseased lymph nodes.
Pathogenesis
It is most common in childhood, and may be primary or secondary to intestinal or pulmonary tuberculosis. In primary cases, the bacteria mostly enter the lymph nodes directly through the healthy intestinal wall, or the original lesion in the intestinal wall has completely healed. In secondary cases, the majority of cases have visible lesions in the lungs or intestines. Lymph node involvement is most frequent in the ileocecal region, in the retroperitoneal space on the medial side of the cecum and ascending colon, and in the inferior portion of the mesentery of the small intestine. Occasionally, lymph nodes in the upper abdomen can have tuberculous lesions. Depending on the stage of the disease, the involved lymph nodes can be acutely enlarged, caseous, suppurative, or sclerotic and calcified. Some calcified lymph nodes may be hard as a stone and may resemble renal or gallbladder stones on x-ray, often requiring pyelography or cholangiography to identify them. In some cases, caseous or cold abscesses of the lymph nodes may be fused into a mass as large as a fist, requiring open abdominal exploration to identify them.
Symptoms
The patient has persistent low-grade fever and fatigue. The umbilicus or right lower abdomen often has persistent vague pain, sometimes intensified in paroxysms, and may also manifest as acute abdominal pain, similar to colic, accompanied by nausea, vomiting, and may have diarrhea or constipation. On examination, enlarged lymph nodes can be palpated around the umbilicus or in the left upper abdomen or right lower abdomen, and there is pressure pain, which is often suspected to be acute appendicitis and surgery is performed. In chronic mesenteric lymph node tuberculosis, chronic toxic symptoms and malnutrition may appear, manifesting as prolonged irregular low-grade fever, loss of appetite, emaciation, anemia, fatigue, diarrhea. Sometimes massively enlarged lymph nodes can be palpated, which are relatively fixed and not easy to push. The enlarged lymph nodes may compress the portal vein to obstruct the reflux, resulting in ascites and abdominal wall varicose veins; compress the inferior vena cava to cause lower limb edema; compress the pylorus to cause pyloric obstruction; and compress the intestinal tract to cause incomplete intestinal obstruction. Adults may lack clinical symptoms and present with a palpable abdominal mass around the umbilicus, which is found to be lymph node tuberculosis on dissection.
Examination
1. Erythrocyte sedimentation rate
The erythrocyte sedimentation rate is often obviously accelerated, which can be used as one of the indicators to assess the activity degree of tuberculosis.
2. Blood routine
①White blood cell count is normal and lymphocytes are increased. Hemoglobin is slightly decreased.
3. Plasma protein
Nearly 20% of chronic patients have hypoproteinemia.
4. Tuberculin test
Tuberculin 1:10,000 test is positive and has reference value.
5. Abdominal plain film
Scattered calcified shadows in the mesentery, especially outside the terminal ileum.
6. Barium meal imaging
If combined with intestinal tuberculosis, intestinal tachycardia can be seen, and the lesion segment is contracted by stimulation with poor filling. When the lesion invades the small intestine, the barium meal may pass through the small intestine with agitation, and the power of the small intestine may be strengthened, resulting in stenosis.
7. Chest X-ray
Pulmonary tuberculosis foci can be detected.
8. Smear and culture
Finding antacid bacilli from the plasma cavity fluid is an important means of diagnosing tuberculosis, but the positive rate is low, only 20%～30%.
9. Antibody test for Mycobacterium tuberculosis
In the past, antibodies (PPD-IgG, PPD-IgM) were detected with natural antigens such as PPD with poor sensitivity and specificity. Due to the preparation of purified or semi-purified antigens of Mycobacterium tuberculosis, the detection of antibodies specific to Mycobacterium tuberculosis has made significant progress. Commonly used purified antigens include recombinant 38kD tuberculin protein antigen.
10. Enzyme-linked immunosorbent assay (ELISA)
ELISA is used to detect anti-tuberculosis antibodies in serum, cerebrospinal fluid and plasma membrane fluid of tuberculosis patients, which can be used as an auxiliary diagnostic index.
11. Enzyme-linked immunoelectrophoresis technology (ELIEP)
ELISA and electrophoresis are combined in an immunological technique, which is a serological method for auxiliary diagnosis of various tuberculosis diseases.
12. Mycobacterium tuberculosis antigen detection
ELISA, latex agglutination test, reverse passive hemagglutination test and other methods are used to detect M. tuberculosis antigen in body fluids.
13. Mixed lymphocyte culture + interferon assay.
Diagnosis
1. history of eating unpasteurized milk, history of tuberculosis contact or history of tuberculosis.
2. Clinical features
Gastrointestinal symptoms and signs: abdominal pain, diarrhea or constipation, abdominal mass; symptoms of tuberculosis toxicity: fever, night sweats, loss of appetite, emaciation. Anti-tuberculosis treatment is effective.
3. Tuberculin test
Strongly positive or other immunological tests are positive.
4. X-ray examination
Caseous necrotic lesions in mesentery.
5. General diagnosis
Diagnosis can be decided on the basis of history of tuberculosis exposure positive tuberculin test, clinical symptoms, deep palpation of the abdomen and rectal exploration, etc. Abdominal radiographs may reveal calcified foci, which are helpful in confirming the diagnosis in the course of chronic evolution and repeated deterioration of the disease.
Differential diagnosis
The differential diagnosis should consider chronic or acute appendicitis. According to the children with tuberculosis of the mesenteric lymph nodes treated by people, the largest number have been misdiagnosed as appendicitis, even for 2-3 years. Hepatitis, non-specific mesenteric lymphadenitis, encopresis, ascariasis, etc. are the next most common causes. In addition, the occasional need to distinguish between gastric and duodenal ulcers, cholecystitis abdominal lymph node mass, should be distinguished from limited ileitis, lymphosarcoma and other abdominal tumors.
Treatment
1. Principles of treatment
Attention should be paid to nutrition, and food containing more protein, vitamins and iron should be consumed. It should be treated with anti-tuberculosis drugs, basically in the same way as tuberculosis peritonitis, and the course of treatment should be 1~1.5 years. When the enlarged lymph nodes compress the intra-abdominal organs and produce corresponding symptoms, and the internal medicine treatment is ineffective, surgery can be considered to release the compression. Lymph nodes with caseous necrosis can be removed by removing the caseous material. The remaining lymph nodes that do not produce compression symptoms are generally not treated.
2. Anti-tuberculosis treatment
Selection of anti-tuberculosis drugs: the treatment of tuberculous mesenteric lymphitis is similar to that of tuberculosis in other parts of the body, but the course of treatment must be 1 to 1.5 years. For first-treatment cases, first-line drugs such as streptomycin, isoniazid, pyrazinamide and rifampicin are preferred. In order to delay or prevent the development of drug resistance, combination therapy with 2 to 3 drugs is now emphasized, and the relapse rate after 6 months of combined treatment with rifampicin, isoniazid and streptomycin is only 3%. In case of secondary tuberculous mesenteric lymphadenitis, the patient may have been treated with anti-tuberculosis drugs and developed some resistance to the first-line drugs, the second-line drugs can be considered, such as ethambutol, ethylthioisophosphamide, kanamycin and cyclosporine. Treatment regimen: ① 2HSP/10HP; ② 2HSE/10HE. generally within 1 to 2 weeks after the start of treatment, the patient’s self-conscious symptoms can be improved, appetite increased, body temperature and stools tend to normalize. However, if the treatment is not timely. If the course of the disease is already in the late stage, even if reasonable and sufficient anti-tuberculosis treatment is given, it still cannot prevent the occurrence of complications.
3. Symptomatic treatment
(1) Diarrhea Antidiarrheal drugs, such as montelukast, alkaline bismuth carbonate (bismuth subcarbonate), etc., can be used.
(2) Abdominal pain Give belladonna, atropine and other drugs, and in severe cases, give fluids and potassium salts.
(3) Incomplete obstruction In addition to the above symptomatic treatment, gastrointestinal decompression should be performed.
(4) Caesarean section
This disease is often suspected as acute appendicitis and surgery is performed. Intraoperatively, it can be found that the appendix is mostly normal, but most of the mesenteric lymph nodes are enlarged, and there can be a small amount of fluid in the abdominal cavity. At this time, the appendix can be removed as usual, one lymph node can be removed for biopsy, and the abdominal cavity can be sutured but not drained, and most of the patients can be cured.
Prognosis
The prognosis of the disease is good after active treatment, and the lymph node caseous lesions may gradually be absorbed, calcify and heal spontaneously. Chronic toxic symptoms may persist for a long time before disappearing. Lymph node caseous necrosis and liquefaction, broken into the abdominal cavity or outside the abdominal wall to form a fistula for a long time, this case is called mesenteric tuberculosis, which is very rare nowadays. When combined with peritonitis and intestinal tuberculosis, the prognosis is directly related to the two diseases.
Prevention
1. Control the source of infection
(1) The main source of tuberculosis is tuberculosis patients. If sputum tuberculosis positive patients receive reasonable chemotherapy at an early stage, the tuberculosis bacilli in the sputum can be reduced in a short period of time, or even disappear, and almost 100% of them can be cured. Therefore, the early detection of the patients, especially bacillus-positive patients, and the timely provision of reasonable chemotherapy is the center of the modern tuberculosis prevention and treatment work. The method of early detection of patients is to carry out X-ray chest radiography and bacteriologic examination of suspected patients in time.
(2) Reducing the chance of transmission Tuberculosis smear-positive patients are the main source of transmission of pediatric tuberculosis. Early detection and reasonable treatment of smear-positive tuberculosis patients are the fundamental measures for the prevention of pediatric tuberculosis. Family members of infants and young children with active TB should undergo detailed examination (chest X-ray, PPD, etc.). Regular medical checkups should be given to the staff of elementary school and child care institutions, so as to detect and isolate the source of infection in time, which can effectively reduce the chances of pediatric tuberculosis infection.
(3) Popularize BCG vaccination Practice has proved that BCG vaccination is an effective measure to prevent pediatric tuberculosis. BCG vaccine can be injected on the same day with hepatitis B vaccine in the neonatal period.
2. Cut off the infectious pathway
Mycobacterium tuberculosis is mainly transmitted through the respiratory tract, so spitting is prohibited. The sputum, daily necessities of patients with positive bacteria and things around them should be sterilized and properly treated, indoor disinfection can be done by ultraviolet radiation, food utensils used by patients can be boiled, bedding can be exposed to sunlight, sputum box and commode can be soaked with 5%-10% Lysol; usually, indoor ventilation and clean air should be maintained, and bathing and changing of clothes should be done diligently.
3. Protection of susceptible people
(1) BCG vaccination, it is a kind of live bacterial vaccine without pathogenicity, after inoculation in the human body, it can make those who are not infected by tuberculosis obtain specific immunity against tuberculosis, the protection rate is about 80%, and it can be maintained for 5-10 years; the target of inoculation is mainly for newborn babies and infants, primary and secondary school and university students, and newly entered the city of the ethnic minority areas; however, the immunity generated from BCG inoculation is relative, and it should be emphasized that other Preventive measures should be emphasized.
(2) Improve the ability to resist infection and self-protection, establish good hygiene and living behavior habits, don’t smoke, don’t abuse alcohol, take baths regularly, ensure sufficient sleep, balance diet, reasonable nutrition, strengthen physical exercise, prevent colds, use antibiotics reasonably; reduce contact with tuberculosis patients, and take precautionary measures such as visiting patients with the permission of the doctor or wearing a mask.
4. Preventive chemotherapy is mainly used for the following patients
① infants and young children under 13 years of age who have not been vaccinated with BCG and have a positive tuberculin test; ② close contact with open tuberculosis patients (mostly family members); ③ tuberculin test has recently turned from negative to positive; ④ tuberculin test is strongly positive; ⑤ tuberculin test-positive children need to use adrenocorticotropic hormone or other immunosuppressive drugs for a longer period of time.