Management of Worsening Pubic Area Infection Unresponsive to Amoxicillin

Introduction to Management

The American College of Physicians and other medical societies recommend switching immediately to an oral antibiotic with MRSA coverage, such as trimethoprim-sulfamethoxazole or doxycycline, and performing incision and drainage if a drainable abscess is present, as amoxicillin lacks coverage against Staphylococcus aureus producing beta-lactamase, which is the most common pathogen in purulent skin infections originating from hair follicles in the pubic region 1

The Infectious Diseases Society of America suggests examining carefully for fluctuance, induration, or a defined collection, and if present, incision and drainage is the primary treatment and may be sufficient alone for simple abscesses 2
For simple abscesses without significant surrounding cellulitis, the World Health Organization notes that I&D alone without antibiotics is often adequate 2

The Centers for Disease Control and Prevention recommend trimethoprim-sulfamethoxazole (TMP-SMX) 1-2 double-strength tablets twice daily for 7-10 days, or doxycycline 100 mg twice daily for 7-10 days, for outpatient oral therapy with MRSA coverage 1, 3
The American College of Cardiology is not directly involved in these recommendations, however clindamycin 300-450 mg three times daily for 7-10 days can be used if local resistance rates are low, as stated by the Clinical Microbiology and Infection journal 1

The World Journal of Emergency Surgery states that immediate referral for IV antibiotics and surgical evaluation is required if systemic signs of infection, such as fever, tachycardia, or hypotension, are present 2, 4
The European Centre for Disease Prevention and Control notes that rapid progression of erythema/swelling despite appropriate antibiotics, crepitus, skin necrosis, or bullae, and severe pain out of proportion to examination findings, are all indications for hospitalization 2, 4

The World Journal of Emergency Surgery describes Fournier's Gangrene as a necrotizing soft tissue infection of the perineum/genitals that can arise from seemingly minor infections like ingrown hairs, and requires immediate broad-spectrum IV antibiotics and urgent surgical debridement 2
The Clinical Microbiology and Infection journal notes that higher risk is present in diabetic, obese, or immunocompromised patients, and mortality approaches 20-40% if treatment is delayed 1, 3

The Infectious Diseases Society of America recommends a regimen of vancomycin 15-20 mg/kg IV every 8-12 hours, plus either piperacillin-tazobactam 3.375-4.5 g IV every 6-8 hours or ceftriaxone 1-2 g IV daily plus metronidazole 500 mg IV every 8 hours, for complex perineal/pubic abscess with cellulitis 1, 2, 3

The World Journal of Emergency Surgery suggests examining for abscess, assessing for systemic signs, and starting oral TMP-SMX or doxycycline if stable, with re-evaluation in 48-72 hours 1, 2, 4
The Clinical Microbiology and Infection journal recommends culturing any purulent drainage to guide therapy if the patient fails to improve 1