Laryngeal tuberculosis is the most common of all otorhinolaryngic tuberculosis, which is mostly caused by open tuberculosis spread through the airway, and rarely by primary tuberculosis. It is caused by infection with Mycobacterium tuberculosis and is found in the posterior part of the larynx, as well as in the vocal cords, ventricular cords, and epiglottis. The disease should be treated and isolated promptly.
I. Etiology
1. Etiology: It is an infection of Mycobacterium tuberculosis. Contact infection in the larynx is caused by bacterial sputum adhering to the mucosa or mucosal folds of the larynx, and the bacteria invade the deep mucosa through tiny wounds or glandular duct openings.
2.Pathological typing: The pathological changes of laryngeal nodules are mainly of 3 lesion natures: exudation, metaplasia and hyperplasia. Generally, it can be divided into 3 types.
① infiltrative type: limited mucosal congestion, edema, and lymphocytic infiltration under the mucosa, forming nodules.
②Ulcer type: caseous necrosis occurs in the center of the tuberculous nodule, forming a tuberculous ulcer, often accompanied by secondary infection. It is characterized by an uneven subterranean margin around the ulcer. Lesion development may invade the laryngeal cartilage membrane and chondromalacia may occur.
(iii) Proliferative type: advanced infiltrative lesions have proliferation of fibrous tissue, and when the disease improves, it may show scar healing and some lesions form tuberculoma.
II. Clinical manifestations
1.Symptoms: Early laryngeal tuberculosis may have no conscious symptoms, and is only found in routine laryngeal examination. Early symptoms of laryngeal tuberculosis may include laryngeal discomfort, irritation, burning and dryness. The change of hoarseness is progressive, but it also depends on the location and extent of the lesion, and the articulation is easily exhausted in the early stage, and gradually becomes hoarse and weak. If lesions and ulcers occur in the epiglottis, arytenoid cartilage and aryteno-epiglottic fold, there will be painful swallowing and difficulty in swallowing. If the lesion occurs on both sides, the laryngeal pain is especially severe and often radiates to the ear, thus affecting eating. If the lesion invades the cartilage, the above symptoms are even more severe. The occurrence of edema and tuberculoma can block the larynx and cause difficulty in breathing. In addition, there are symptoms of tuberculosis, such as cough, sputum, fever, emaciation and anemia.
2.Signs: Laryngoscopic examination may reveal the following changes.
(1) One side of the vocal folds or the arytenoids and the arytenoid cartilage are obviously congested and the mucosa is rough.
(2) shallow ulcers with rat bite or jagged irregularities on the edge of the vocal cord or epiglottis.
(③Phialine vocal fold protrusion or interphialine granulation tissue hyperplasia.
④Heavy pale edema and thickening of the laryngeal ventricular mucosa or phialine cartilage.
⑤ Restricted or fixed vocal fold movement.
(6) Tumor-like tuberculoma occurs at the root of the epiglottis or other sites.
(7) Chondromalacia and cartilage necrosis may lead to inflammatory adhesions of the cricoarytenoid joint or laryngeal stenosis.
(8) Laryngeal scar contraction causes laryngeal stenosis.
⑨ Acute cornu laryngeal nodules with swelling of the mucosa of the pharynx and larynx with scattered small nodules, or pale gray ulcers. It is obvious at the epiglottis and phialic cleft, and there is salivary retention.
3. Complications: It can be complicated by hoarseness, sore throat, painful swallowing, cough, blood in sputum, blood in snot, fever, night sweats, emaciation (malnutrition) and other symptoms of systemic toxicity, or lymphatic masses, etc.
III. Medical examination
1, sputum tuberculosis bacillus examination: sputum detection of tuberculosis bacillus is the most reliable basis for the diagnosis of tuberculosis disease. At present, sputum examination methods are used: sputum smear or collection of bacteria to find acid-resistant bacilli, or sputum culture of tuberculosis bacteria.
2, tuberculin test: this test positive reaction to tuberculosis infection has a positive value. It is generally used for adolescent and pediatric TB patients. A positive reaction caused by adults is generally only considered to have had tuberculosis infection and has no clinical diagnostic significance.
3, serological examination: enzyme-linked immunosorbent assay (ELISA) detection of tuberculosis antibodies, positive results have some value for the diagnosis of tuberculosis.
IV. Diagnostic basis
1.History of pulmonary tuberculosis.
2. Hoarseness and weakness of pronunciation, pain in the larynx, which may radiate to the ear in severe cases and affect eating. If there is tuberculoma or edema, it may cause difficulty in breathing.
3. The laryngeal mucosa is pale, with submerged rodent-like shallow ulcers and uneven margins. They are mostly found in the posterior part of the larynx, such as the arytenoid process and the arytenoid space.
V. Diseases that are easily misdiagnosed
It should be differentiated from laryngeal cancer, laryngeal nodule combined with squamous carcinoma and laryngeal nodule with pseudoepithelioma-like hyperplasia.
Treatment principles
1. Systemic anti-tuberculosis treatment: laryngeal tuberculosis often occurs after pulmonary tuberculosis. Chemotherapy is the main means to reduce the incidence, reduce and eliminate the source of infection. In recent years, research on tuberculosis has developed by leaps and bounds. With the progress of basic research on tuberculosis, bacteriology and pharmacology, and the discovery of new anti-tuberculosis drugs, there are some new approaches and perspectives in the modern treatment of tuberculosis. At present, the treatment of tuberculosis mostly uses the combination of two or more drugs, which can ensure that even if there is a primary drug resistance to one drug, there are still two sensitive drugs combined to ensure successful treatment and reduce treatment failure.
(1) Standard treatment protocol: In principle, all patients undergoing chemotherapy need to be treated regularly under the supervision and guidance of medical personnel.
It can be divided into two phases.
(1) Induction phase: i.e., elimination of a great part of the TB bacilli in a short period of time. The drug regimen: streptomycin, isoniazid, and sodium para-aminosalicylate (or ethambutol) in triple doses once daily for 2 months. Outpatient treatment is usually used, and those with severe disease may be hospitalized.
(2) Continuing treatment phase: After completing the intensive treatment phase, streptomycin and sodium para-aminosalicylate (or ethambutol) can be continued to be applied for 10-22 months of home treatment in order to keep the tuberculosis bacilli from developing a delayed growth period, administered twice a week.
(2) Short course of treatment regimen: that is, in a short course of treatment, quickly kill the tuberculosis bacteria in the organism. The regimen is: four drugs with streptomycin, isoniazid, rifampin and pyrazinamide, followed by isoniazid and rifampin for 4 months after 2 months; or three drugs with ethambutol, isoniazid and rifampin, for 4 months, or three drugs with isoniazid, rifampin and pyrazinamide, for 4 months, or isoniazid for 6 months.
2.Immunotherapy: When the patient’s immune function is low, phagocytes cannot effectively destroy all intracellular tuberculosis bacteria and form granulomatous lesions and appear epithelioid cells, which not only cannot remove the infecting bacteria, but also the infecting bacteria can grow and multiply in them. Therefore, immunotherapy can be considered for those who have reduced indicators measured by immunological examination.
VII. Prevention
1.Prognosis: The prognosis of laryngeal tuberculosis is determined by the following factors. ①Lung lesion. Tuberculosis and laryngeal nodules affect each other, and the prognosis is better in patients with chronic fibrous tuberculosis. The occurrence of laryngeal nodules also reduces the recovery rate of pulmonary tuberculosis. ②The patient’s general condition and resistance. (iii) Location and extent of local lesions. The prognosis is good if the nodular lesion is confined to a small part of the larynx, the infiltration is very slow, and the surface is flat and non-ulcerated. If the infiltration occurs in the arytenoids and the vocal cords show ulcers, the patient is mostly painless and does not hinder eating, and the prognosis is also good. Those whose lesions are confined to the epiglottis can be cured. Where infiltration and swelling of the arytenoid cartilage and epiglottis occur, and invade the cartilage membrane and cartilage, the prognosis is not good. ④Patients with laryngeal tuberculosis who also have syphilis and diabetes mellitus have a poor prognosis. ⑤ Pregnancy often makes pulmonary tuberculosis and laryngeal nodules heavier, and the prognosis is poor.
2.Prevention.
①Control the source of infection: Infiltrative and chronic fibro-cavernous tuberculosis patients with bacilli excretion is the main source of infection of tuberculosis. Patients with positive sputum tuberculosis should be properly isolated and treated early to prevent secondary laryngeal tuberculosis. In dairy cattle with tuberculosis, if the excreted tuberculosis bacteria contaminate the milk, such as incomplete disinfection can cause human disease. Therefore, strict management and disinfection of dairy cattle and milk should be strengthened, eliminating sick cattle, milk should be sterilized at low temperature.
② Cut off the transmission route: tuberculosis bacteria invade the human body mainly through the respiratory tract transmission. By air droplets, droplet nuclei, dust transmission, etc.. Whether this route of transmission can be cut off, and social environmental health and personal hygiene knowledge is closely related. Patients should be educated to cover their mouth and nose with a handkerchief when coughing and sneezing to prevent spraying infectious droplets. Develop good hygiene habits, do not spit anywhere, and properly handle and disinfect the sputum coughed up by the patient. Burning, deep burying, 75% ethanol, 35%-40% propanol or 2% lysol disinfection and boiling for 20min can kill the tuberculosis bacteria in the patient’s sputum. In addition, when eating with patients at the same table, we advocate the communal chopsticks system and the sharing system, and the food utensils used by patients should be disinfected by boiling; the pathogen can be killed immediately at 100℃, 10min at 70℃, and 1h at 60℃. It can reduce the chance of transmission of TB bacteria.