Group A beta-hemolytic streptococcal infections.

GABHS is the most common bacterial cause of tonsillopharyngitis, but this organism also produces acute otitis media; pneumonia; skin and soft-tissue infections; cardiovascular, musculoskeletal, and lymphatic infections; bacteremia; and meningitis. Most children and adolescents who develop a sore throat do not have GABHS as the cause; their infection is viral in etiology. Other bacterial pathogens produce sore throat infrequently (e.g., Chlamydia pneumoniae and Mycoplasma pneumoniae), and when they do, other concomitant clinical illness is present. Classic streptococcal tonsillopharyngitis has an acute onset; produces concurrent headache, stomach ache, and dysphagia; and upon examination is characterized by intense tonsillopharyngeal erythema, yellow exudate, and tender/enlarged anterior cervical glands. Unfortunately only about 20% to 30% of patients present with classic disease. Physicians overdiagnose streptococcal tonsillopharyngitis by a wide margin, which almost always leads to unnecessary treatment with antibiotics. Accordingly, use of throat cultures and/or rapid GABHS detection tests in the office is strongly advocated. Their use has been shown to be cost-effective and to reduce antibiotic overprescribing substantially. Penicillin currently is recommended by the American Academy of Pediatrics and American Heart Association as first-line therapy for GABHS infections; erythromycin is recommended for those allergic to penicillin. Virtually all patients improve clinically with penicillin and other antibiotics. However, penicillin treatment failures do occur, especially in tonsillopharyngitis in which 5% to 35% of patients do not experience bacteriologic eradication. Penicillin treatment failures are more common among patients who have been treated recently with the drug. Cephalosporins or azithromycin are preferred following penicillin treatment failures in selected patients as first-line therapy, based on a history of penicillin failures or lack of compliance and for impetigo. GABHS remain exquisitely sensitive to penicillin in vitro. There are several explanations for penicillin treatment failures, but the possibility of copathogen co-colonization in vivo has received the most attention. Treatment duration with penicillin should be 10 days to optimize cure in GABHS infections. A 5-day regimen is possible and approved by the United States Food and Drug Administration for cefpodoxime (a cephalosporin) and azithromycin (a macrolide). Prevention of rheumatic fever is the primary objective for antibiotic therapy of GABHS infections, but a reduction in contagion and faster clinical improvement also can be achieved. Development of streptococcal toxic shock syndrome and necrotizing fasciitis ("flesh-eating bacteria") are rising concerns. The portal of entry for these invasive GABHS strains is far more often skin and soft tissue than the tonsillopharynx.