Pilonidal Abscess Antibiotic Dosing
For pilonidal abscess, incision and drainage is the primary treatment, and antibiotics are typically NOT required unless there are systemic signs of infection (fever, tachycardia, elevated WBC) or significant surrounding cellulitis. When antibiotics are indicated, amoxicillin-clavulanate (Augmentin) 875/125 mg orally twice daily for 5-7 days is the recommended regimen. 1
Primary Treatment Approach
Incision and drainage is the definitive treatment for pilonidal abscess, and systemic antibiotics are usually unnecessary unless fever or other evidence of systemic infection is present. 1 The IDSA guidelines emphasize that the decision to add antibiotics should be based on the presence or absence of systemic inflammatory response syndrome (SIRS), defined as:
- Temperature >38°C or <36°C
- Tachypnea >24 breaths/minute
- Tachycardia >90 beats/minute
- WBC >12,000 or <4,000 cells/µL 1
When Antibiotics ARE Indicated
Antibiotics should be added as adjunctive therapy in the following situations:
- Presence of SIRS criteria (as defined above) 1
- Markedly impaired host defenses (immunocompromised patients, diabetes) 1
- Significant surrounding cellulitis with erythema and induration extending >5 cm from the abscess 1
- Recurrent pilonidal abscess after drainage and culture 1
Specific Antibiotic Dosing
When antibiotics are warranted, amoxicillin-clavulanate 875/125 mg orally twice daily is the appropriate choice for pilonidal abscess. 2, 3 This dosing provides coverage against the polymicrobial flora typically involved, including anaerobes and aerobes. 4, 5
Duration of Treatment
- 5-7 days of antibiotic therapy is recommended for skin and soft tissue infections after clinical improvement 2
- For recurrent abscesses with positive cultures, a 5-10 day course targeting the isolated pathogen is appropriate 1
Alternative Regimens for Perineal Location
Since pilonidal disease occurs in the sacrococcygeal/perineal region, coverage for anaerobes is important. For patients requiring IV therapy or with severe infection:
- Metronidazole 500 mg every 8 hours IV plus either ciprofloxacin, levofloxacin, or ceftriaxone 1
- Ampicillin-sulbactam 3 g every 6 hours IV for broader coverage 1
Clinical Evidence Supporting This Approach
Research demonstrates that aspiration plus oral antibiotics (cefalexin and metronidazole for 7 days) was effective in 83% of pilonidal abscess cases, with high patient satisfaction. 4 Another study showed 95% success with aspiration and empirical antibiotics (covering anaerobes and aerobes), allowing conversion to elective surgery. 5
A case report documented successful treatment of actinomycotic pilonidal abscess with oral amoxicillin-clavulanate for one week after surgical drainage. 3 This supports the adequacy of short-course oral therapy when drainage is adequate.
Critical Pitfalls to Avoid
- Do not prescribe antibiotics for simple pilonidal abscess without systemic signs - this promotes antimicrobial resistance without clinical benefit 1
- Do not rely on antibiotics alone without drainage - surgical drainage is the cornerstone of treatment 1, 4, 5
- Do not use antibiotics active against MRSA routinely unless there is purulent drainage, injection drug use, or known MRSA colonization 1
- Ensure anaerobic coverage given the perineal location - amoxicillin-clavulanate provides this, but plain amoxicillin does not 1, 4