How should I evaluate and manage a teenage patient with a painless cervical lymph node suspected to be scrofula, including diagnostic workup, anti‑tubercular therapy dosing, monitoring, and indications for surgery?

Management of Scrofula (Cervical Lymphadenitis) in Teenagers

For a teenage patient with painless cervical lymphadenopathy suspected to be scrofula, excisional surgery without chemotherapy is the definitive treatment if nontuberculous mycobacteria (NTM) is confirmed, achieving approximately 95% cure rates, while tuberculous lymphadenitis requires standard anti-tubercular therapy with close monitoring for drug resistance. 1

Initial Diagnostic Evaluation

Clinical Assessment

• Determine laterality and characteristics: NTM lymphadenitis presents as unilateral (95% of cases), non-tender cervical adenopathy developing insidiously without systemic symptoms 2
• Age consideration: While peak incidence for NTM is 1-5 years, teenagers can develop either NTM or tuberculous lymphadenitis, with the latter being more common in adolescents 1, 2
• Assess for risk factors: Foreign birth, BCG vaccination status, family history of tuberculosis, and HIV status are critical 3

Tuberculin Skin Testing

• Perform PPD tuberculin skin test immediately: A strongly positive result (≥15 mm) suggests tuberculous rather than NTM etiology 1
• Distinguish TB from NTM: Only ~10% of culture-proven mycobacterial cervical lymphadenitis in children is tuberculosis, but this distinction fundamentally changes treatment and requires public health notification 2

Microbiological Diagnosis

• Excisional biopsy is both diagnostic and therapeutic: Send tissue for acid-fast bacilli (AFB) smear, mycobacterial culture, and histopathology 1, 3
• Culture is essential: Determines species identification and drug susceptibility patterns, particularly important given multi-drug resistant TB cases have been identified in teenagers 3
• Fine needle aspiration has limitations: While it can provide initial cytological diagnosis, excisional biopsy provides superior diagnostic yield and is often curative for NTM 2

Critical pitfall: Incisional biopsy alone or aspiration frequently leads to persistent disease, sinus tract formation, and chronic drainage—these procedures should be avoided 1

Treatment Based on Etiology

For Nontuberculous Mycobacterial (NTM) Lymphadenitis

Complete excisional surgery without chemotherapy is the treatment of choice, with 95% success rate 1, 2

Surgical Approach

• Perform complete excision of affected nodes: Partial removal or incisional biopsy leads to treatment failure 1
• For recurrent disease: Second surgical procedure is usually performed 1

When Surgery is High-Risk

• Use clarithromycin-based multidrug regimen: For nodes at risk of facial nerve involvement (preauricular location) or recurrent disease after surgery 1
• Regimen composition: Clarithromycin combined with ethambutol and rifampin (same as for MAC pulmonary disease) 1
• Duration: 6-12 months of therapy, though optimal duration is not definitively established 1

For Tuberculous Lymphadenitis

Initiate standard anti-tubercular therapy immediately if tuberculosis is confirmed or strongly suspected 1, 4

Initial Phase (2 months)

• Four-drug regimen: Isoniazid (INH), rifampin (RIF), pyrazinamide (PZA), and ethambutol (EMB) 1
• Dosing for adolescents: Use adult dosing schedules
  • INH: 5 mg/kg daily (max 300 mg) or 15 mg/kg three times weekly (max 900 mg)
  • RIF: 10 mg/kg daily (max 600 mg) or 10 mg/kg three times weekly (max 600 mg)
  • PZA: 25 mg/kg daily or 35 mg/kg three times weekly
  • EMB: 15-20 mg/kg daily 1

Continuation Phase (4 months)

• Two-drug regimen: INH and RIF for additional 4 months 1, 4
• Total duration: 6 months for drug-susceptible disease 4

When Susceptibility is Unknown

• Start anti-TB therapy while awaiting culture: Particularly if PPD is strongly positive (≥15 mm) or risk factors for TB exist 1
• Adjust based on culture results: Discontinue if cultures are negative and no TB risk factors present; modify regimen based on drug susceptibility testing 1

Critical consideration: Multi-drug resistant TB has been identified in teenagers with cervical lymphadenitis, making culture and susceptibility testing mandatory 3

Monitoring During Treatment

For NTM (Surgical Management)

• Post-operative follow-up: Monitor surgical site for healing, sinus tract formation, or recurrence 1
• If medical therapy used: Monthly clinical assessments for adverse drug reactions (less than 2% rate) 1

For Tuberculous Lymphadenitis

• Monthly clinical evaluations: Assess for treatment response and adverse effects 1
• Visual acuity testing: Monthly for patients on ethambutol to detect optic neuritis 1
• Liver function monitoring: Baseline and as clinically indicated for hepatotoxicity 1
• Paradoxical reactions: May occur with temporary worsening of lymphadenopathy; manage symptomatically with NSAIDs or prednisone 1-2 mg/kg/day for severe cases 1

Directly Observed Therapy (DOT)

• Mandatory for all tuberculous cases: Ensures adherence and prevents development of drug resistance 1
• Consider for NTM on medical therapy: Particularly in adolescents where adherence may be challenging 1

Indications for Surgery in Tuberculous Lymphadenitis

Surgery is indicated for tuberculous lymphadenitis in specific circumstances 3:

• Ongoing suppuration despite adequate anti-tuberculous treatment: Some patients develop culture-negative suppuration requiring surgical drainage for cure 3
• Diagnostic purposes: When microbiological confirmation cannot be obtained by other means 3
• Excisional biopsy is both diagnostic and therapeutic: Provides tissue for culture and drug susceptibility testing while potentially being curative 3

Important caveat: If excisional biopsy is performed before diagnosis, ensure tissue is sent for mycobacterial culture to identify drug resistance patterns 3

Source Case Investigation

For confirmed tuberculous lymphadenitis, identify the source case 1:

• Screen household members and close contacts: Parents and caregivers should undergo chest radiography to exclude pulmonary TB 1
• Public health notification: Tuberculous lymphadenitis requires reporting to local health authorities 2
• Contact investigation: Particularly important in teenagers who may have adult-type disease with potential for transmission 1