Chapter 130. Streptococcal and Enterococcal Infections (Part 4)

Gas Pharyngitis: TreatmentIn the usual course of uncomplicated streptococcal pharyngitis, symptoms resolve after 3–5 days. The course is shortened little by treatment, which is given primarily to prevent suppurative complications and ARF. Prevention of ARF depends on eradication of the organism from the pharynx, not simply on resolution of symptoms, and requires 10 days of penicillin treatment (Table 130-3). Erythromycin may be substituted for penicillin in cases of penicillin allergy. Oncedaily azithromycin is a more convenient but expensive alternative; a 5-day course is approved, but only limited data support equivalent efficacy to a standard 10-day course. ...
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Chapter 130. Streptococcal and Enterococcal Infections (Part 4) Chapter 130. Streptococcal and Enterococcal Infections (Part 4) Gas Pharyngitis: Treatment In the usual course of uncomplicated streptococcal pharyngitis, symptomsresolve after 3–5 days. The course is shortened little by treatment, which is givenprimarily to prevent suppurative complications and ARF. Prevention of ARFdepends on eradication of the organism from the pharynx, not simply on resolutionof symptoms, and requires 10 days of penicillin treatment (Table 130-3).Erythromycin may be substituted for penicillin in cases of penicillin allergy. Once-daily azithromycin is a more convenient but expensive alternative; a 5-day courseis approved, but only limited data support equivalent efficacy to a standard 10-daycourse. Table 130-3 Treatment of Group A Streptococcal Infections Infection Treatmenta Pharyngitis Benzathine penicillin G, 1.2 mU IM; or penicillin V, 250 mg PO tid or 500 mg PO bid x 10 days (Children of empyema Streptococcal toxic Penicillin G, 2–4 mU IV q4h; plusshock syndrome clindamycin,b 600–900 mg q8h; plus intravenous immunoglobulin,b 2 g/kg as a single dose a Penicillin allergy: Erythromycin (10 mg/kg PO qid up to a maximum of250 mg per dose) may be substituted for oral penicillin. Alternative agents forparenteral therapy include first-generation cephalosporins—if the nature of theallergy is not an immediate hypersensitivity reaction (anaphylaxis or urticaria) oranother potentially life-threatening manifestation (e.g., severe rash and fever)—orvancomycin. b Efficacy unproven, but recommended by several experts. See text fordiscussion. Resistance to erythromycin and other macrolides is common amongisolates from several countries, including Spain, Italy, Finland, Japan, and Korea.Macrolide resistance may be becoming more prevalent elsewhere with theincreasing use of this class of antibiotics. In areas with resistance rates exceeding5–10%, macrolides should be avoided unless results of susceptibility testing areknown. Follow-up culture after treatment is no longer routinely recommended butmay be warranted in selected cases, such as those involving patients or familieswith frequent streptococcal infections or those occurring in situations in which therisk of ARF is thought to be high (e.g., when cases of ARF have recently beenreported in the community). Complications Suppurative complications of streptococcal pharyngitis have becomeuncommon with the widespread use of antibiotics for most symptomatic cases.These complications result from the spread of infection from the pharyngealmucosa to deeper tissues by direct extension or by the hematogenous or lymphaticroute and may include cervical lymphadenitis, peritonsillar or retropharyngealabscess, sinusitis, otitis media, meningitis, bacteremia, endocarditis, andpneumonia. Local complications, such as peritonsillar or parapharyngeal abscessformation, should be considered in a patient with unusually severe or prolongedsymptoms or localized pain associated with high fever and a toxic appearance.Nonsuppurative complications include ARF (Chap. 315) and PSGN (Chap. 277),both of which are thought to result from immune responses to streptococcalinfection. Penicillin treatment of streptococcal pharyngitis has been shown toreduce the likelihood of ARF but not that of PSGN. Bacteriologic Treatment Failure and the Asymptomatic Carrier State Surveillance cultures have shown that up to 20% of individuals in certainpopulations may have asymptomatic pharyngeal colonization with GAS. There areno definitive guidelines for management of these asymptomatic carriers or ofasymptomatic patients who still have a positive throat culture after a full course oftreatment for symptomatic pharyngitis. A reasonable course of action is to give asingle 10-day course of penicillin for symptomatic pharyngitis and, if positivecultures persist, not to re-treat unless symptoms recur. Studies of the naturalhistory of streptococcal carriage and infection have shown that the risk both ofdeveloping ARF and of transmitting infection to others is substantially loweramong asymptomatic carriers than among individuals with symptomaticpharyngitis. Therefore, overly aggressive attempts to eradicate carriage probablyare not justified under most circumstances. An exception is the situation in whichan asymptomatic carrier is a potential source of infection to others. Outbreaks offood-borne i ...