Mycobacterial cervical lymphadenitis

Mycobacterial Cervical Lymphadenitis

A depiction of scrofula, historically associated with mycobacterial cervical lymphadenitis.

Mycobacterial cervical lymphadenitis, also known as scrofula, is a condition characterized by the infection and inflammation of the cervical lymph nodes due to mycobacterial species. This condition is most commonly caused by Mycobacterium tuberculosis and non-tuberculous mycobacteria (NTM), such as Mycobacterium avium complex.

Etiology

The primary causative agents of mycobacterial cervical lymphadenitis are mycobacteria, which are a type of bacteria known for their acid-fast properties. The most common mycobacteria involved are:

• Mycobacterium tuberculosis: The bacterium responsible for tuberculosis, which can spread to the lymph nodes.
• Non-tuberculous mycobacteria (NTM): These include species such as Mycobacterium avium and Mycobacterium intracellulare, which are more commonly associated with scrofula in children.

Pathophysiology

Infection typically occurs when mycobacteria enter the body through the respiratory tract or skin and are transported to the cervical lymph nodes via the lymphatic system. The immune response to the infection leads to the formation of granulomas, which are collections of immune cells that attempt to contain the bacteria. Over time, these granulomas can become necrotic and caseous, leading to the characteristic swelling and inflammation of the lymph nodes.

Clinical Presentation

Patients with mycobacterial cervical lymphadenitis often present with:

• Painless swelling of the cervical lymph nodes
• Firm, rubbery nodes that may become fluctuant over time
• Possible overlying skin changes, such as erythema or ulceration
• Systemic symptoms such as fever, night sweats, and weight loss, particularly in cases caused by Mycobacterium tuberculosis

Diagnosis

Diagnosis of mycobacterial cervical lymphadenitis involves a combination of clinical evaluation, imaging, and laboratory tests. Key diagnostic steps include:

• Fine needle aspiration or excisional biopsy of the affected lymph node for histopathological examination and culture.
• Polymerase chain reaction (PCR) testing to identify mycobacterial DNA.
• Imaging studies such as ultrasound or CT scan to assess the extent of lymph node involvement.

Treatment

The treatment of mycobacterial cervical lymphadenitis depends on the causative organism:

• For Mycobacterium tuberculosis: A standard anti-tuberculous regimen is used, typically including isoniazid, rifampicin, ethambutol, and pyrazinamide.
• For non-tuberculous mycobacteria: Treatment may involve surgical excision of the affected nodes and antibiotics such as clarithromycin or azithromycin.

Prognosis

The prognosis for patients with mycobacterial cervical lymphadenitis is generally good with appropriate treatment. However, untreated or inadequately treated cases can lead to complications such as fistula formation or dissemination of the infection.

Related Pages

• Tuberculosis
• Lymphadenopathy
• Non-tuberculous mycobacteria