What does a large cold abscess mean?

Cold Abscess: Definition and Management

A large cold abscess refers to a substantial collection of pus without the typical inflammatory signs of heat, redness, or tenderness, most commonly caused by tuberculosis infection. 1, 2

Characteristics of Cold Abscesses

• Cold abscesses lack the cardinal signs of inflammation (calor, dolor, rubor) that are typically seen in pyogenic abscesses 3
• They present as chronic, painless or minimally painful swellings that may gradually increase in size 2
• Most commonly caused by Mycobacterium tuberculosis, representing approximately 1% of extrapulmonary tuberculosis cases 2
• The chest wall is a frequent location, though they can occur in other areas including subcutaneous tissue and muscle 1, 2

Diagnostic Approach

• Imaging studies are essential for diagnosis, with CT scan with IV contrast being the preferred modality 4
• Clinical suspicion should be high in patients with:
  • History of tuberculosis (present in 50-83% of cases) 1, 5
  • Chronic parietal swelling without significant inflammatory signs 2
  • Symptoms persisting for weeks to months (average 2.8 months) 2
• Fever is often absent (present in only 37.5% of cases in one study) 2

Management Strategy

Diagnostic Confirmation

• Surgical biopsy with histopathological examination is often required for definitive diagnosis 1
• Specimens should be sent for:
  • Histopathology (positive in 62.5% of cases) 2
  • Bacteriological culture (positive in 50% of cases) 2
  • GeneXpert testing when available 2

Treatment Approach

• Complete surgical excision of the abscess including debridement of involved tissue is mandatory to prevent recurrence 6
• Simple drainage without complete excision has a significantly higher recurrence rate (40% vs 9.2%) 6
• Anti-tuberculous therapy should be initiated after surgical intervention 1, 6
  • Standard regimen includes Isoniazid, Rifampicin, Pyrazinamide, and Ethambutol 1
  • Treatment duration ranges from 6-9 months 1
  • In complex cases or inadequate drainage, treatment may extend to 2-6 weeks 4

Special Considerations

• Multifocal cold abscesses may occur in approximately 12.5% of cases 2
• Associated active pulmonary or extrapulmonary tuberculosis should be ruled out, as it is present in a significant number of cases 2
• Immunocompromised patients may require broader antimicrobial coverage and longer treatment duration 4

Prognosis

• With appropriate surgical management and anti-tuberculous therapy, the cure rate is high (83-100%) 1, 2
• Recurrence is rare with complete surgical excision followed by adequate anti-tuberculous therapy 6
• Complications are minimal when proper surgical technique is employed 1

Monitoring and Follow-up

• Regular assessment for signs of recurrence or treatment failure is necessary 4
• Patients with persistent symptoms beyond the expected treatment period warrant further investigation 4
• Long-term follow-up is recommended to detect late recurrences 6