Streptococcal, Group A Infections

Key Features

• Arthritis, pneumonia, empyema, endocarditis, and necrotizing fasciitis are relatively uncommon infections that may be caused by group A β-hemolytic streptococci

Clinical Findings

• Arthritis generally occurs in association with cellulitis

• Pneumonia and empyema often are characterized by

  • Extensive tissue destruction

  • Aggressive, rapidly progressive clinical course

• Endocarditis (rare)

  • Should be suspected when bacteremia accompanies pneumonia, particularly if the patient uses injection drugs

  • Tricuspid valve is most commonly involved

• Any streptococcal infection, especially necrotizing fasciitis, can be associated with streptococcal toxic shock syndrome, characterized by invasion of skin or soft tissues, acute respiratory distress syndrome, and kidney failure

Diagnosis

• Culture of affected site or blood

Treatment

• Arthritis

  • Penicillin G aqueous, 2 million units every 4 hours intravenously

  • Frequent percutaneous needle aspiration

• Pneumonia/empyema

  • Penicillin G aqueous, 4 million units every 4 hours intravenously

  • Chest tube drainage for treatment of the empyema

• Endocarditis

  • Penicillin G aqueous, 4 million units every 4 hours intravenously for 4 weeks

  • Vancomycin, 1 g intravenously every 12 hours, is recommended for persons allergic to penicillin

• Necrotizing fasciitis: early, extensive débridement is essential for survival

• Toxic shock syndrome

  • Penicillin G aqueous 4 million units every 4 hours intravenously

  • Consider the addition of clindamycin, 600 mg every 8 hours intravenously, to halt toxin production, and intravenous immune globulin, 0.5 g/kg once daily for 5–6 days or a single dose of 2 g/kg with a repeat dose at 48 hours if the patient remains unstable