What is the appropriate management of scrofula (cervical tuberculous lymphadenitis)?

Management of Scrofula (Cervical Tuberculous Lymphadenitis)

For tuberculous cervical lymphadenitis, treat with standard 6-month antituberculous chemotherapy (rifampicin, isoniazid, pyrazinamide, and ethambutol for 2 months, followed by rifampicin and isoniazid for 4 months), reserving surgery primarily for diagnostic purposes or refractory cases with persistent suppuration. 1

Primary Treatment Approach

Standard Chemotherapy Regimen

The cornerstone of scrofula management is medical therapy using the same regimen as pulmonary tuberculosis:

• Initial phase (2 months): Rifampicin, isoniazid, pyrazinamide, and ethambutol 1
• Continuation phase (4 months): Rifampicin and isoniazid 1
• Total duration: 6 months 1

Dosing for adults:

• Rifampicin: 450 mg daily (<50 kg) or 600 mg daily (>50 kg) 1
• Isoniazid: 300 mg daily 1
• Pyrazinamide: 1.5 g daily (<50 kg) or 2.0 g daily (>50 kg) 1
• Ethambutol: 15 mg/kg daily 1

The British Thoracic Society guidelines confirm that the 6-month short course regimen is as effective as 9-month regimens for peripheral lymph node tuberculosis 1. This represents a significant departure from older, prolonged treatment approaches.

Role of Surgery

Surgery is NOT the primary treatment for scrofula. The evidence strongly favors medical management:

• Surgical excision is reserved for: 1

  • Diagnostic purposes when fine needle aspiration is non-diagnostic 2, 3
  • Extensive lymphadenitis with poor response to medical therapy 1
  • Persistent suppuration despite adequate antituberculous treatment 2

• Surgical excision as primary treatment achieves >90% cure rates but is unnecessary when medical therapy is effective 1

• Avoid incision and drainage: This technique is associated with prolonged wound discharge, fistula formation, and scarring 1, 4

• Therapeutic aspiration may be beneficial for large fluctuant nodes about to drain spontaneously, though this has not been systematically studied 1, 5

Diagnostic Workup

Essential Pre-Treatment Assessments

Before initiating therapy, obtain:

1. Visual acuity testing (Snellen chart) for all patients who will receive ethambutol 1

   • Document that the patient understands to stop ethambutol immediately if visual changes occur 1
   • For children or patients with language barriers, educate family members 1

2. Renal function testing before using streptomycin or ethambutol 1

   • Avoid these drugs in renal failure or monitor serum drug concentrations with dose reduction 1

3. Baseline liver function tests (AST/ALT, bilirubin) for all patients 1

Microbiological Confirmation

Fine needle aspiration (FNA) is the most reliable initial diagnostic method:

• FNA cytology yields positive diagnosis in 90% of cases 6, 7
• Acid-fast bacilli smears from FNA are positive in the majority of patients 3
• FNA is more sensitive than histologic examination of excised nodes 3

Always obtain mycobacterial culture and drug susceptibility testing to identify drug resistance patterns 2. Multidrug-resistant TB has been identified in cases where initial biopsies were not cultured 2.

Polymerase chain reaction (PCR) analysis has lower sensitivity (63%) compared to FNA cytology 6 but can provide rapid results.

Monitoring During Treatment

Liver Function Monitoring

The monitoring strategy depends on baseline liver status:

For patients with chronic liver disease:

• Monitor liver enzymes weekly for 2 weeks, then every 2 weeks for the first 2 months 1

For patients with normal baseline liver function:

• Routine monitoring is NOT required 1
• Repeat liver function tests only if symptoms develop (fever, malaise, vomiting, jaundice, unexplained deterioration) 1

Management of hepatotoxicity:

• Stop rifampicin, isoniazid, and pyrazinamide if AST/ALT rises to ≥5 times normal or bilirubin rises 1
• If patient is well and non-infectious, withhold treatment until liver function normalizes 1
• If patient is unwell or smear-positive, substitute streptomycin and ethambutol until recovery 1

Visual Monitoring

• Patients on ethambutol must be able to report visual symptoms 1
• Instruct patients to stop ethambutol immediately if visual changes occur 1

Clinical Response Assessment

Paradoxical reactions are common and expected:

• Lymph nodes may enlarge and new nodes can appear during or after therapy without bacteriological relapse 1, 5
• This does NOT indicate treatment failure 1
• Continue medical therapy; do not perform therapeutic excision for paradoxical enlargement 1

Special Populations

HIV-Positive Patients

Rifampicin significantly reduces protease inhibitor levels through CYP3A enzyme induction 1. Three management options exist:

1. Preferred: Discontinue protease inhibitor and use alternative antiretroviral drugs until tuberculosis treatment is complete 1
2. Omit rifampicin and extend treatment to 18 months 1
3. Substitute rifabutin (reduced dose) for rifampicin and use indinavir as the protease inhibitor 1

Pediatric Patients

• Use the same 6-month regimen 1
• Dosing: Isoniazid 5 mg/kg, rifampicin 10 mg/kg, pyrazinamide 35 mg/kg, ethambutol 15 mg/kg 1
• Note: The majority of lymphatic mycobacterial disease in US children is caused by nontuberculous mycobacteria, not M. tuberculosis 1

Nontuberculous Mycobacterial (NTM) Lymphadenitis

If NTM (particularly MAC) is identified:

• Primary treatment is surgical excision with >90% cure rate 1
• Macrolide-based medical regimen should be considered for extensive disease or poor surgical response 1
• This represents a key distinction from tuberculous lymphadenitis, where surgery is not primary therapy 1

Common Pitfalls and Caveats

1. Do not extend treatment beyond 6 months for uncomplicated tuberculous lymphadenitis unless pyrazinamide cannot be used (then extend to 9 months) 1

2. Do not confuse paradoxical enlargement with treatment failure 1, 5

3. Do not perform incision and drainage as this leads to chronic fistulas 1, 4

4. Always obtain cultures before starting treatment to identify drug resistance 2

5. Distinguish tuberculous from nontuberculous mycobacterial infection as management differs significantly 1

6. Check for concurrent pulmonary tuberculosis: Only 16-18% of scrofula patients have chest radiograph abnormalities 6, 7, but sputum should be obtained if pulmonary symptoms are present

7. Consider tuberculosis in all patients with cervical lymphadenopathy, especially those from endemic areas, regardless of age 8