What is the best antibiotic for a patient with an infected pilonidal cyst?

Best Antibiotic for Pilonidal Cyst

Amoxicillin-clavulanate is the preferred empiric antibiotic for infected pilonidal cysts when systemic signs of infection are present, but antibiotics should only be used as adjunctive therapy to incision and drainage, not as primary treatment. 1

Primary Treatment Approach

• Incision and drainage is the cornerstone of treatment for infected pilonidal cysts, with antibiotics reserved strictly as adjunctive therapy. 1, 2
• Antibiotics alone without surgical drainage is the most common reason for treatment failure, regardless of which antibiotic is selected. 2

When to Add Antibiotics

Antibiotics should be added to surgical drainage only when specific criteria are met:

• Systemic inflammatory response syndrome (SIRS) is present, including fever, tachycardia, tachypnea, or abnormal white blood cell count. 1
• Surrounding cellulitis extends more than 5 cm from the wound edge, indicating more extensive soft tissue involvement. 1
• Immunocompromised status is present, as these patients are at higher risk for systemic spread. 1

Recommended Antibiotic Regimens

First-Line Therapy

• Amoxicillin-clavulanate is the preferred empiric choice, providing broad-spectrum coverage against the polymicrobial flora typically found in pilonidal infections, including both aerobic and anaerobic organisms. 1
• Duration should be 7-10 days when systemic signs are present. 1

Alternative Regimens

• Clindamycin 300-450 mg orally three times daily plus trimethoprim-sulfamethoxazole (1-2 double-strength tablets twice daily) is recommended as an alternative first-line option. 2
• Ciprofloxacin plus metronidazole or ceftriaxone plus metronidazole can be used in cases of penicillin allergy or treatment failure. 1
• For penicillin-allergic patients specifically, clindamycin plus ciprofloxacin is an effective combination. 2

Important Caveats and Pitfalls

• Amoxicillin or ampicillin monotherapy should never be used due to poor efficacy and very high resistance rates worldwide. 2
• Beta-lactams generally have inferior efficacy and more adverse effects compared to other antimicrobials for skin infections, which is why combination therapy with clavulanate is essential. 2
• Fluoroquinolones should be reserved for cases where other antibiotics cannot be used due to their potential for collateral damage and promotion of resistance. 2

Management of Recurrent Infections

• For recurrent pilonidal abscesses, culture the abscess and treat with antibiotics active against the isolated pathogen for 5-10 days. 1
• Consider a 5-day decolonization regimen with intranasal mupirocin and chlorhexidine washes for patients with recurrent infections. 2

Duration of Therapy

• For most uncomplicated cases with adequate drainage, 5-7 days of antibiotic therapy is sufficient. 2
• For more severe or complicated infections, treatment may need to be extended to 10-14 days based on clinical response. 2