What is the recommended treatment for skin infections?

Treatment for Skin Infections

The recommended treatment for skin infections includes incision and drainage for abscesos, and antibiotics targeting the causative pathogens, with beta-lactams as first-line therapy for mild to moderate infections and broader coverage for severe or complicated cases. 1

Classification and Treatment by Type of Infection

Uncomplicated Skin Infections

• Impetigo is primarily caused by Streptococcus β-hemolítico and/or Staphylococcus aureus, with increasing prevalence of community-acquired MRSA (CA-MRSA) 2
• For mild and localized impetigo, topical antibiotics are sufficient, while widespread or severe cases require systemic antibiotics like cloxacillin, erythromycin, azithromycin, or cephalexin 3
• Cellulitis is the most common skin and soft tissue infection (59.1% of cases) and may be caused by streptococci (diffuse infection) or staphylococci (more localized infection) 1, 2
• For early, mild cellulitis without significant comorbidities, oral beta-lactams are appropriate in areas where CA-MRSA is not prevalent 1
• The usual adult dose for skin infections is cephalexin 250-500 mg every 6 hours, with 500 mg every 12 hours being an acceptable alternative for skin infections 4
• For pediatric patients, the recommended dosage is 25-50 mg/kg/day in divided doses 4

Abscesses

• For simple superficial abscesses or boils, incision and drainage is the primary treatment, and antibiotics are not needed 1
• Complex skin and subcutaneous abscesses (perianal, perirectal, injection sites) typically respond to incision and drainage with adjuvant antibiotic therapy 1
• Antibiotic therapy is recommended if systemic signs of infection are present, in immunocompromised patients, if source control is incomplete, or in cases of abscess with significant cellulitis 1, 2
• Empiric broad-spectrum antibiotic therapy covering Gram-positive, Gram-negative, and anaerobic bacteria is recommended for complex abscesses 1, 2

Severe/Complicated Infections

• For more severe infections, parenteral antibiotics are the first choice 1
• If MRSA is suspected, glycopeptides (vancomycin) and newer antimicrobials (linezolid, daptomycin) are the best options 1
• For necrotizing fasciitis and streptococcal toxic shock syndrome caused by group A streptococci, clindamycin and penicillin are recommended 1
• For mixed infections, ampicillin-sulbactam plus clindamycin plus ciprofloxacin is recommended 1
• For pediatric patients with skin and skin structure infections, ceftriaxone 50-75 mg/kg once daily (not exceeding 2 grams) is recommended 5
• For adults with serious infections, ceftriaxone 1-2 grams daily (not exceeding 4 grams) is appropriate 5

Antibiotic Selection Based on Suspected Pathogens

For Gram-positive Coverage (Including MRSA)

• First-line (MSSA): Beta-lactams such as dicloxacillin, cephalexin, or amoxicillin-clavulanate 2, 3
• For MRSA: Vancomycin, linezolid, daptomycin, or ceftaroline 1
• For streptococcal infections: Penicillin plus clindamycin (clindamycin suppresses toxin production) 1, 2

For Mixed/Polymicrobial Infections

• Ampicillin-sulbactam (1.5-3.0 g every 6-8 hours IV) or piperacillin-tazobactam (3.37 g every 6-8 hours IV) plus clindamycin (600-900 mg/kg every 8 hours IV) plus ciprofloxacin (400 mg every 12 hours IV) 1
• Alternative regimens include carbapenems (imipenem/cilastatin, meropenem, ertapenem) or cefotaxime plus metronidazole 1, 6

Special Considerations

Immunocompromised Patients

• Immunocompromised patients require very broad-spectrum empirical agents that include coverage for resistant gram-positive bacteria, such as MRSA (vancomycin, linezolid, daptomycin, or quinupristin/dalfopristin) 1
• Coverage for gram-negative bacteria may include monotherapy with an antipseudomonal cephalosporin, carbapenems, or combination therapy with a fluoroquinolone or aminoglycoside plus an extended-spectrum penicillin or cephalosporin 1
• For fungal infections in immunocompromised hosts, empiric antifungal therapy should be added to the antibacterial regimen 1

Duration of Treatment

• For most uncomplicated infections, 7-14 days of therapy is appropriate 4, 3
• For streptococcal infections, treatment should continue for at least 10 days 4, 5
• For necrotizing infections, antibiotics should be continued until no further debridement is needed, the patient has improved clinically, and fever has been absent for 48-72 hours 1, 2

Common Pitfalls to Avoid

• Failing to perform incision and drainage for abscesses, which is the primary treatment for simple abscesses 1, 2
• Underestimating the importance of surgical debridement in necrotizing infections; antibiotics alone are insufficient 2
• Not considering local resistance patterns when selecting empiric antibiotics, particularly for MRSA 7, 8
• Delaying appropriate broad-spectrum coverage in severe infections while awaiting culture results 1
• Using high-pressure irrigation for wounds, which can spread bacteria into deeper tissue layers 2
• Not adjusting therapy based on culture results and clinical response 1, 2

By following these evidence-based recommendations, clinicians can effectively manage the spectrum of skin infections from mild superficial cases to severe, life-threatening infections.