A 12-year-old child presents with a dry cough and fever that have persisted for the last four weeks. A chest x-ray shows hilar lymphadenopathy on the right side and consolidation of the right middle lobe.
Which of the following conditions is the most likely diagnosis?
A. Pneumococcal pneumonia
B. Benign tumour of the right bronchus
C. Primary pulmonary tuberculosis
D. Interstitial lung disease
E. Hodgkin’s disease
Correct Answer: C. Primary pulmonary tuberculosis
Explanation:
This child’s clinical presentation of dry cough, fever, and hilar lymphadenopathy on chest x-ray suggests a pulmonary infection with lymphatic involvement. The most likely diagnosis is primary pulmonary tuberculosis (TB), particularly given the findings of right-sided hilar lymphadenopathy and lung consolidation, which are classic signs of tuberculosis.
Key Features Supporting Primary Pulmonary Tuberculosis:
- Chronic Cough and Fever:
- These are classic symptoms of pulmonary tuberculosis (TB), which often presents with persistent symptoms such as dry cough and low-grade fever, which can last for weeks or even months.
- Chest X-ray Findings:
- Hilar lymphadenopathy: Enlarged lymph nodes at the hilum are a typical finding in primary TB.
- Consolidation of the right middle lobe: Pulmonary TB can cause consolidation in one or both lungs, especially in the upper lobes or middle lobe. In TB, lymphatic involvement is common, leading to hilar lymphadenopathy.
- Age Group:
- TB is still prevalent in children, especially in regions where the disease burden is high. It can present with fever, weight loss, cough, and lymphadenopathy, making it a strong consideration.
Why Other Options Are Incorrect:
A. Pneumococcal Pneumonia:
- Pneumococcal pneumonia often presents with a productive cough (with sputum), high fever, and is more likely to cause lobar consolidation rather than just hilar lymphadenopathy.
- Pneumococcal pneumonia is typically a more acute illness, and the chronic nature of the symptoms in this child makes TB a more likely diagnosis.
B. Benign Tumor of the Right Bronchus:
- Benign tumors, such as bronchial adenomas, usually cause obstruction and lead to localized symptoms like recurrent infections, but they would not typically present with hilar lymphadenopathy and the systemic symptoms (fever, prolonged cough) seen in this child.
D. Interstitial Lung Disease:
- Interstitial lung disease (ILD) is uncommon in children and would present with more diffuse interstitial markings and bilateral lung involvement rather than localized consolidation and hilar lymphadenopathy.
- It is usually chronic and associated with shortness of breath rather than fever.
E. Hodgkin’s Disease:
- While Hodgkin’s lymphoma can cause hilar lymphadenopathy, it typically presents with more generalized symptoms such as weight loss, night sweats, and painless lymphadenopathy rather than an infectious process with consolidation in the lungs.
- The chronic fever and cough with chest findings are more in keeping with an infectious process like TB rather than lymphoma.
Further Investigations:
- Sputum Examination:
- A sputum smear for acid-fast bacilli (AFB) or culture for Mycobacterium tuberculosis is essential to confirm the diagnosis of pulmonary tuberculosis.
- Tuberculin Skin Test (TST) or Interferon-Gamma Release Assay (IGRA):
- These tests can help assess latent TB infection and provide supportive evidence for a TB diagnosis.
- CT Chest:
- A CT scan of the chest can help evaluate the extent of lung consolidation and lymphadenopathy, which can provide further details for a diagnosis of pulmonary tuberculosis.
- HIV Testing:
- Given the increased risk of TB in immunocompromised individuals, HIV testing may be recommended, particularly if the child has risk factors.
Management:
- Antituberculosis Treatment:
- First-line TB therapy typically includes a combination of isoniazid (INH), rifampicin, pyrazinamide, and ethambutol for the initial phase of treatment.
- Supportive Care:
- Adequate nutrition, hydration, and monitoring for drug side effects are essential during treatment.
Conclusion:
The child’s presentation of dry cough, fever, hilar lymphadenopathy, and lung consolidation most strongly suggests primary pulmonary tuberculosis. This condition should be confirmed with sputum tests, chest imaging, and possibly a tuberculin skin test. Early diagnosis and appropriate antituberculosis treatment are crucial to preventing complications and transmission.