Pharyngeal Tuberculosis Clinical Manifestations, Diagnostic Challenges, and Treatment Approaches in Extra-Pulmonary Tuberculosis

Abstract
Pharyngeal tuberculosis (PTB) is an uncommon form of extra-pulmonary tuberculosis (EPTB) that affects the oropharynx, nasopharynx, or hypopharynx. Although rare, it presents a significant diagnostic challenge due to its resemblance to other infectious or malignant lesions of the throat. The disease is primarily caused by Mycobacterium tuberculosis and can occur as a primary infection or secondary to pulmonary tuberculosis. This article reviews the pathophysiology, clinical presentation, diagnostic methods, and management strategies of pharyngeal tuberculosis, emphasizing the importance of early detection and multidisciplinary treatment to prevent complications and transmission.

Introduction

Tuberculosis (TB) remains one of the most prevalent infectious diseases worldwide. While the lungs are the primary site of infection, extra-pulmonary tuberculosis (EPTB) can involve various organs, including the ear, nose, and throat (ENT) region. Among these, pharyngeal tuberculosis is a rare manifestation, accounting for less than 2% of all EPTB cases. However, due to its nonspecific symptoms and clinical resemblance to pharyngitis, tonsillitis, or even malignancies, it often leads to misdiagnosis or delayed treatment.

The pharynx, which connects the nasal and oral cavities to the esophagus and larynx, is constantly exposed to pathogens. When infected by Mycobacterium tuberculosis, the mucosal lining of the pharynx becomes inflamed and ulcerated, leading to discomfort, difficulty in swallowing, and voice changes. Early identification of PTB is crucial to avoid complications and prevent community transmission.

Pathophysiology

Pharyngeal tuberculosis can occur in two forms:

1. Primary PTB: Occurs without pulmonary involvement, usually through ingestion of M. tuberculosis bacilli in contaminated sputum or food.
2. Secondary PTB: Develops due to direct spread from active pulmonary tuberculosis through coughing or swallowing infected sputum.

The nasopharynx, oropharynx, and hypopharynx can all be affected. The infection typically begins as mucosal ulceration, leading to caseous necrosis and granuloma formation. In advanced stages, fibrotic scarring may result in difficulty swallowing or airway narrowing.

Clinical Presentation

The symptoms of pharyngeal tuberculosis vary depending on the site and severity of infection. Common clinical manifestations include:

• Sore throat (persistent and non-responsive to antibiotics)
• Dysphagia (difficulty swallowing)
• Odynophagia (painful swallowing)
• Voice changes or hoarseness
• Weight loss and fever
• Cervical lymphadenopathy (swollen neck glands)
• Cough with or without hemoptysis

According to Iqbal et al. (2024), pharyngitis accounted for 20.16% of ENT-related tuberculosis symptoms in their study of extra-pulmonary TB patients. The frequency was highest in patients with 6–12 months of symptom duration, indicating that chronic infection plays a key role in disease persistence.

Diagnosis

Diagnosing pharyngeal tuberculosis requires a high level of clinical suspicion, particularly in patients with persistent throat symptoms unresponsive to standard treatment.

1. Clinical Examination:
   The pharyngeal mucosa may appear ulcerated, nodular, or hypertrophic. Lesions often resemble malignant growths, necessitating biopsy for confirmation.
2. Endoscopy:
   Naso- or oropharyngoscopy provides a detailed view of mucosal lesions. Typical findings include multiple shallow ulcers with irregular margins and surrounding inflammation.
3. Histopathology:
   Biopsy samples show granulomatous inflammation with caseation necrosis and the presence of Langhans giant cells, confirming tuberculosis.
4. Microbiological Tests:

• AFB staining of sputum or swabs
• Mycobacterial culture for definitive identification
• GeneXpert MTB/RIF assay to detect rifampicin resistance

5. Imaging Studies:
   Chest X-rays and CT scans are performed to identify pulmonary involvement or regional lymph node enlargement.
6. Differential Diagnosis:
   Pharyngeal tuberculosis must be differentiated from:

• Malignant tumors of the throat
• Fungal infections (e.g., histoplasmosis)
• Syphilitic ulcers
• Chronic tonsillitis or peritonsillar abscess

Treatment and Management

Pharyngeal tuberculosis is curable with appropriate anti-tubercular therapy (ATT). The standard WHO-recommended 6-month regimen is effective in most cases:

Intensive Phase (2 months):
Isoniazid + Rifampicin + Pyrazinamide + Ethambutol

Continuation Phase (4 months):
Isoniazid + Rifampicin

Adjunctive measures include pain management, maintaining hydration, and nutritional support. Corticosteroids may be considered in cases of severe inflammation or airway compromise.

Surgical intervention is rarely required, but it may be necessary to drain abscesses or remove necrotic tissue in advanced cases. Regular follow-ups are essential to monitor recovery and rule out relapse.

Complications

Untreated or advanced pharyngeal tuberculosis can lead to:

• Airway obstruction
• Fibrotic scarring causing swallowing difficulty
• Spread to adjacent organs (larynx or esophagus)
• Tuberculous lymphadenitis
• Systemic dissemination

Prognosis

The prognosis of pharyngeal tuberculosis is generally favorable with early diagnosis and proper treatment. Most patients recover fully without long-term complications. However, delayed diagnosis may lead to structural damage and chronic scarring of the pharynx.

Public Health Significance

Pharyngeal tuberculosis, though rare, has significant public health implications because of its potential for transmission through coughing and saliva. Healthcare workers must use protective measures during examination, and patients should be educated about completing their anti-tubercular regimen to prevent recurrence.

Conclusion

Pharyngeal tuberculosis remains an under-recognized but clinically important form of extra-pulmonary tuberculosis. Its nonspecific presentation often delays diagnosis, increasing the risk of complications and transmission. Awareness among clinicians and the use of modern diagnostic techniques—such as endoscopy and GeneXpert testing—can greatly improve early detection. Comprehensive treatment with anti-tubercular therapy ensures excellent recovery and prevents recurrence. Timely recognition, patient education, and multidisciplinary management are key to controlling this rare form of tuberculosis.

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