Laryngeal Tuberculosis in a 7-Year-old Child: A Case Report and Literature Review

To the Editors: Laryngeal tuberculosis (TB) is a rare manifestation of extrapulmonary TB, at present the incidence rate is 1% of all cases, compared to in the 20th century, the impacted rate was 25%–30% of all TB cases.1 Here, we present a case of laryngeal TB with miliary TB and tuberculous encephalitis, presented with a sore throat, hoarseness, severe cough and acute obstruction of the larynx. A 7-year and 3-month-old female was admitted to West China Second University Hospital with the complaint of cough with yellowish purulent sputum, sore throat, hoarseness for 1 month and dyspnea for 1 day. One month before admission, she developed cough 1–2 times, which gradually aggravated into a severe string cough, lasting for several minutes each time with a large amount of yellow purulent sputum, and it is significant at night and in the morning, accompanied by night sweats, loss of appetite, vomiting and abdominal pain. At the same time, there is hoarseness of voice and sore throat that was more obvious while swallowing. Bilateral cervical lymph nodes grew up gradually, without fever, pain, hemoptysis, etc. After relevant examinations, the local hospital diagnosed “miliary pulmonary tuberculosis (PTB)” and “cervical lymph node TB” and gave isoniazid, rifampicin, pyrazinamide and ethambutol anti-TB therapy. One day before the child’s condition worsened, she developed shortness of breath, cyanosis around the lip, progressive dyspnea, repeated vomiting, irritability and fever with 38 °C and was transferred to our hospital. She had lost 2 kg in the past 1 month. The grandmother of the child had a long-term cough and weight loss without a definite diagnosis, and the child had close contact with her. She has completed her childhood immunization. Physical examination on admission: ill-looking, malnourished appearance, febrile 38 °C, no chills and rigor. Bacille Calmette-Guérin scar was seen in her left upper arm. She had mildly subintercostal retraction with stridor. Hoarseness, incitement of nasal wings, bilateral wheezes and no dry and wet rales were heard. Bilateral nontender, multiple cervical lymph nodes were palpable with an acceptable range of motion. Color Doppler ultrasound of the neck showed lymphadenopathy (25 × 16 mm on the right side and 15 × 11 mm on the left side). Sputum for acid-fast bacilli was negative and T-SPOT was positive. The X-pert mycobacterium tuberculosis/resistance to rifampin test on the gastric juice demonstrated a diagnosis of rifampicin-sensitive TB. Cerebrospinal fluid (CSF) examination including X-pert mycobacterium tuberculosis/resistance to rifampin was negative. Computed tomography (CT) of the chest features revealed miliary TB with hilar and mediastinal lymphadenopathy, partial calcification and bilateral thickening of the pleura. No abnormalities were found in cranial CT. The diagnosis of tuberculous encephalitis was made based on magnetic resonance imaging (MRI) findings, which revealed multiple small nodules in the bilateral cerebral hemispheres and right thalamus, which showed nodular enhancement. Bronchoscopy showed multiple nodules in the lateral pharyngeal wall and around the larynx, epiglottis, bilateral arytenoid pharyngeal folds and vocal cords, with edema and erosion, swelling and thickening of the bilateral vocal cords, subglottic mucosal swelling and multiple nodules. The patient was initiated with an anti-TB regimen of isoniazid, rifampin, pyrazinamide and ethionamide but the child’s condition remained unchanged with severe, irritating and paroxysmal cough, hoarseness and sore throat; thereafter, we performed a bronchoscopy, which revealed laryngeal TB. Meanwhile, MRI showed tuberculous encephalitis. Therefore, we added dexamethasone (0.6 mg/kg/d) and continued anti-TB therapy. After 2 weeks of therapy, the child general condition including cough, sore throat and hoarseness improved significantly. Laryngeal TB is characterized as a soft tissue thickening and infiltration of the pre-epiglottic and paraglottic spaces. According to a few reports, laryngeal TB may occur without pulmonary TB involvement,2 but the most frequent secondary cause in majority of the cases is the complication of PTB, accounting for 15%–37% of the cases of PTB, when the tubercle bacilli can be readily manifested in the sputum and accumulated in the larynx.3 Indeed, the bacilli are often carried here by the blood and lymph streams since bacteremia has been proved in systemic TB.2 Compared with the child group, laryngeal TB is more dominant in the elderly, especially in males and people over 50 years old.4 We summarized the findings of the case series and case reports, and found a total of 19 articles through literature search with 25 cases were reported in the medical literature. Since 1960, 9 cases of laryngeal TB in children and a few more cases have been reported in the world literature.5 A summary of the reported cases of laryngeal TB in children is detailed in Table, Supplemental Digital Content 1, https://links.lww.com/INF/F321. The mean age was 9.2 years (range between 7 months and 15 years). Gender distribution varies between reports. However, the predominance of male has been reported in most of the previous studies, particularly among the older age groups,5 but in the pediatric series, we found a female predominance accounting for 56% while the male 40%, 1 patient was not included due to missing gender. A total of 36% (9/22) cases were diagnosed with PTB, 12% (3/22) with miliary TB and 45.45% (10/22) with no history of TB. An autopsy examination of 2 children who died revealed laryngeal TB and 1 child died after the diagnosis,6 Constitutional symptoms such as weight loss, fatigue, night sweats, fever, hemoptysis, cough and odynophagia were common in the past, but at present, hoarseness, stridor and dysphagia are the most frequent symptoms of laryngeal TB. Airway obstruction associated with stridor in laryngeal TB or lymph node enlargement may lead to vascular obstruction, as per several reports, particularly in children. This case presented with second-degree laryngeal obstruction due to the compression of the airway by an enlarged lymph node. Patients with laryngeal TB can be affected in any part of the larynx but generally tubercular lesions are found in the true vocal folds, false vocal cord epiglottis and aryepiglottic fold arytenoids, followed by posterior commissure.2,7 However, a number of sites can be affected, as observed in our case, where multiple sites were involved, which was confirmed by bronchoscopy. Additionally, this child developed tuberculous encephalopathy and had no definite neurological deficit except drowsiness and CSF examination was negative; however, a pathological finding of cranial enhanced MRI revealed a feature of tuberculous encephalitis. In our literature, we could not find any reported cases of developing tuberculous encephalitis. It is believed that TB encephalopathy is an uncommon manifestation and often seen in children. It is hematogenous spread from pulmonary TB. Characterized by diffuse cerebral damage with TB, reported in children population, with similar features of acute disseminated encephalopathy,8 few studies have found that CSF tests are negative for those who are eventually diagnosed with tuberculous meningitis, although this is rare. In terms of identifying central nervous system TB, enhanced MRI is preferred over CT. MRI of tuberculous encephalopathy shows significant cerebral edema, which can be unilateral or bilateral T1-weighted images hyperintensity, including affected white matter, can be noticed.9 The treatment of laryngeal TB is with 4 anti-TB drugs and it has good response with satisfactory prognosis. In this series, we found that the majority of patients were treated with the same regimen in certain patient combination treatments including streptomycin and para-aminosalicylic acid, which is the standard recommended regimen.5 The use of supplementary corticosteroids in laryngeal TB is controversial and has limited data to support it. However, corticosteroid is beneficial when upper respiratory symptoms are involved, especially with a sign of airways obstruction. Our patient significantly improved after initiating anti-TB regimen including corticosteroids. Anti-TB drugs are the cornerstone for laryngeal TB, and hormone therapy can improve symptoms when there is a risk of airways obstruction. Children with miliary TB have the increased risk of central nervous system involvement, thus awareness should be raised.