Treatment of Abscess Without Drainage

Clinical Decision Algorithm

For immunocompetent, non-critically ill patients, antibiotics alone may be considered primary treatment when percutaneous drainage is not feasible or not available, patient is clinically stable without signs of septic shock, and abscess is small 1, 2
The American College of Surgeons recommends antibiotic duration of 7 days for small abscesses without drainage 1, 2
For critically ill or immunocompromised patients, surgical intervention should be considered as primary treatment when percutaneous drainage is not feasible or not available, patient shows signs of systemic illness or septic shock, and patient has significant immunosuppression 1, 2

Empiric broad-spectrum coverage is essential, with options including Piperacillin/tazobactam 4 g/0.5 g q6h or 16 g/2 g by continuous infusion, and alternative Eravacycline 1 mg/kg q12h 1
For patients with inadequate/delayed source control, Carbapenem therapy is recommended, with options including Ertapenem 1 g q24h 1, 3

Patients treated with antibiotics alone without drainage require careful clinical monitoring for resolution of inflammatory processes, serial assessment of clinical conditions and inflammation indices, and diagnostic investigation if ongoing signs of infection or systemic illness persist beyond 7 days of antibiotic treatment 1, 2, 4

For simple cutaneous abscesses, incision and drainage is the primary treatment, with antibiotics recommended only for severe/extensive disease, rapid progression with cellulitis, systemic illness, immunosuppression, extremes of age, difficult-to-drain locations, or lack of response to drainage alone 5
For complex abscesses, such as perianal or perirectal abscesses, antibiotic therapy is recommended if systemic signs of infection are present, source control is incomplete, or significant cellulitis is present, with empiric broad-spectrum coverage including Gram-positive, Gram-negative, and anaerobic bacteria 6, 7
For intra-abdominal abscesses, small diverticular abscesses can be treated with antibiotic therapy alone for 7 days, while large diverticular abscesses require percutaneous drainage combined with antibiotics for 4 days, or antibiotics alone in stable, immunocompetent patients with careful clinical monitoring 1, 2, 4