What is the recommended approach for treating preauricular lymphadenitis?

Preauricular Lymphadenitis: Clinical Approach

Primary Treatment Strategy

For non-tuberculous mycobacterial (NTM) preauricular lymphadenitis, excisional surgery without chemotherapy is the definitive treatment, but carries significant risk of facial nerve injury—therefore, a clarithromycin-based multidrug regimen should be considered as first-line therapy when preauricular nodes are involved. 1, 2

Diagnostic Evaluation

Initial Assessment

• Obtain tuberculin skin test (PPD) in all suspected cases to distinguish tuberculous from NTM lymphadenitis 1
• Perform Gram stain and culture of aspirated material from the affected lymph node 2
• Consider fine needle aspiration for cytopathology, though utility is variable (granulomata or mixture of degenerating granulocytes, lymphocytes, and epithelioid histiocytes support diagnosis) 1
• Assess for specific etiologies: cat scratch disease (Bartonella henselae), tularemia, gonococcal/chlamydial conjunctivitis with preauricular spread, or Parinaud oculoglandular syndrome 1, 3

Key Clinical Distinctions

• NTM lymphadenitis: typically no TB exposure history, negative family PPD tests, normal chest radiograph; PPD reactions range from negative to >10mm in up to one-third of cases 1
• Tuberculous lymphadenitis: strongly positive PPD (≥15mm), TB risk factors, requires anti-TB therapy and public health tracking 1

Treatment Algorithm by Etiology

Non-Tuberculous Mycobacterial (NTM) Lymphadenitis

Critical surgical consideration: Excisional biopsy of preauricular lymph nodes carries significant risk of facial nerve injury 1

Primary Treatment Options:

1. For high surgical risk (preauricular location): Clarithromycin-based multidrug regimen (same as used for pulmonary MAC disease) for 6-12 months 1, 2, 4
2. For low surgical risk locations: Complete excisional surgery without chemotherapy (95% success rate) 1, 2, 4

Avoid These Approaches:

• Never perform incisional biopsy alone—leads to persistent disease, sinus tract formation, and chronic drainage 1, 2, 4
• Never use anti-TB drugs without macrolides—results in treatment failure 1, 4

Bacterial Suppurative Lymphadenitis

Early-Stage Without Abscess:

• Clindamycin 300-450 mg orally three times daily OR
• Amoxicillin-clavulanate 875/125 mg orally twice daily 2
• Continue for 7-14 days for staphylococcal/streptococcal infections 2

With Abscess Formation:

• Surgical drainage after marrow recovery (if neutropenic) or for progressive infection 2
• Combine with appropriate antibiotics targeting S. aureus and S. pyogenes 2

Cat Scratch Disease (Bartonella henselae)

Azithromycin is the treatment of choice 2:

• Patients >45 kg: 500 mg on day 1, then 250 mg daily for 4 additional days 2
• Patients <45 kg: 10 mg/kg on day 1, then 5 mg/kg daily for 4 additional days 2

Alternative for severe cases: Doxycycline 100 mg orally twice daily for 3 months (may add rifampicin for 15 days) 3

Parinaud Oculoglandular Syndrome

• Most commonly caused by Bartonella henselae, but also tularemia and sporotrichosis 1
• Bartonella-associated: Often self-limited with improvement over weeks, but antimicrobials hasten resolution 1
• Tularemia-associated:
  • Severe cases: Streptomycin 15 mg/kg IM every 12 hours OR Gentamicin 1.5 mg/kg IV every 8 hours 2
  • Mild cases: Doxycycline 100 mg orally twice daily OR Tetracycline 500 mg orally four times daily 2

Gonococcal/Chlamydial Conjunctivitis with Preauricular Lymphadenopathy

• Gonococcal: Requires systemic antibiotics (per CDC STI guidelines) due to risk of corneal perforation, septicemia, arthritis 1
• Chlamydial trachoma: Systemic antibiotics to prevent corneal scarring, blindness 1

Tuberculous Lymphadenitis (Suspected)

• Initiate anti-TB therapy immediately while awaiting culture results, especially with TB risk factors (positive family history, foreign-born) 1, 2, 4
• Discontinue anti-TB therapy if cultures fail to yield mycobacteria and no significant TB risk factors exist 1, 4

Special Populations

Immunocompromised/Neutropenic Patients:

• Hospitalize for empiric therapy 2
• Vancomycin plus antipseudomonal antibiotics 2
• Surgical drainage after marrow recovery or for progressive infection 2

Recurrent NTM Disease:

• Second surgical procedure is usually performed 1
• Alternative: Clarithromycin multidrug regimen if repeat surgery carries high risk 1, 2

Critical Pitfalls to Avoid

• Never perform incisional biopsy or drainage alone for suspected NTM—this creates chronic fistulae 1, 2, 4
• Recognize preauricular location as high-risk for facial nerve injury during excision 1
• Always obtain cultures before starting antibiotics when possible—only 50-82% of excised nodes yield positive cultures even with compatible histopathology 1
• Do not assume all preauricular swelling is lymphadenitis—consider parotid pathology, infected preauricular sinuses/cysts, or malignancy 3, 5