What are the treatment options for different types of streptococcal infections?

Treatment Options for Different Types of Streptococcal Infections

Treatment for streptococcal infections varies based on the type of infection, with penicillin remaining the cornerstone therapy for most streptococcal infections due to its proven efficacy, narrow spectrum, and low cost. 1

Group A Streptococcal Pharyngitis

First-line Treatment

• Penicillin remains the drug of choice for Group A Streptococcal (GAS) pharyngitis 1:
  • Oral penicillin V for 10 days
  • Intramuscular benzathine penicillin G as a single dose (preferred for patients unlikely to complete oral therapy) 1, 2

Alternative Treatments (for penicillin-allergic patients)

• Erythromycin for 10 days 1, 2
• First-generation cephalosporins (if no immediate hypersensitivity to β-lactams) 1
• Clindamycin (300-500 mg four times daily for 10 days) 1
• Azithromycin (500 mg once daily for 3-5 days) - note that some strains are resistant 1, 3

Treatment Duration

• Standard course is 10 days for most oral antibiotics to achieve maximal pharyngeal eradication 1
• Patients should complete a full 24 hours of antibiotics before returning to school or work to prevent transmission 4

Streptococcal Skin and Soft Tissue Infections

Nonpurulent Cellulitis

• Empirical therapy targeting β-hemolytic streptococci is recommended 1:
  • β-lactam antibiotics (e.g., amoxicillin, cefazolin) 1
  • Treatment duration: 5-10 days, based on clinical response 1

Purulent Skin Infections

• For abscesses, incision and drainage is the primary treatment 1
• Antibiotic therapy indicated for 1:
  • Severe or extensive disease
  • Rapid progression with associated cellulitis
  • Systemic illness
  • Immunocompromised patients
  • Extremes of age
  • Difficult-to-drain areas (face, hand, genitalia)
  • Associated septic phlebitis
  • Lack of response to incision and drainage alone

Complicated Skin and Soft Tissue Infections

• For hospitalized patients with deeper infections, surgical debridement plus antibiotics 1:
  • IV vancomycin (A-I)
  • Oral or IV linezolid 600 mg twice daily (A-I)
  • Daptomycin 4 mg/kg/dose IV once daily (A-I)
  • Telavancin 10 mg/kg/dose IV once daily (A-I)
  • Clindamycin 600 mg IV/PO three times daily (A-III)
• Treatment duration: 7-14 days based on clinical response 1

Necrotizing Fasciitis Caused by Group A Streptococci

• Requires aggressive surgical debridement plus antimicrobial therapy 1
• Recommended antibiotic regimen 1:
  • Combination of clindamycin and penicillin
  • Clindamycin suppresses streptococcal toxin production and has shown superior efficacy to penicillin alone in observational studies

Pediatric Considerations

Pharyngitis

• Same first-line therapy as adults (penicillin) 1, 2
• Amoxicillin is equally effective and more palatable for children 5

Skin Infections

• For minor skin infections (impetigo): mupirocin 2% topical ointment 1
• For complicated infections in hospitalized children 1:
  • Vancomycin (A-II)
  • Clindamycin 10-13 mg/kg/dose IV every 6-8 hours if clindamycin resistance is low (<10%)
  • Linezolid for children >12 years: 600 mg PO/IV twice daily; for children <12 years: 10 mg/kg/dose PO/IV every 8 hours

Important Restrictions

• Tetracyclines should not be used in children <8 years of age 1

Management of Recurrent Streptococcal Infections

• For recurrent GAS pharyngitis 1:

  • Treat with the same antimicrobial as initial episode
  • Consider intramuscular benzathine penicillin G if compliance with oral therapy is questionable
  • For multiple recurrences, clindamycin or amoxicillin/clavulanate may be more effective at eradicating pharyngeal carriage

• For healthcare workers with GAS colonization 1:

  • Treatment options include oral penicillin (500 mg four times daily for 10 days), amoxicillin (500 mg three times daily for 10 days), clindamycin (500 mg four times daily for 10 days), or azithromycin (500 mg once daily for 3 days)
  • For persistent carriage, combination therapy may be needed

Diagnostic Considerations

• Throat culture remains the diagnostic standard for GAS pharyngitis 1, 6
• Rapid antigen detection tests and molecular diagnostic tests can provide faster results with improving sensitivity and specificity 7, 6
• Cultures from abscesses and purulent skin infections are recommended for patients receiving antibiotic therapy, those with severe local infection or systemic illness, and those who have not responded to initial treatment 1

Prevention of Rheumatic Fever

• Primary prevention is accomplished through proper identification and adequate treatment of GAS pharyngitis 2
• Secondary prevention (for those with history of rheumatic fever) requires continuous antimicrobial prophylaxis with penicillin as the agent of choice 2
• Note that while azithromycin is effective in eradicating susceptible strains of GAS, data establishing its efficacy in preventing rheumatic fever are not available 3