Pharyngitis reflects inflammation of the mucous membranes of the pharynx and is manifested clinically as “sore throat”; inflammation of the adjoining tonsils (“tonsillopharyngitis”) or isolated tonsillar infection (“tonsillitis”) is commonly included in this diagnostic category. Pharyngitis may be part of a broader respiratory tract infection or one manifestation of a systemic illness. Stomatitis refers to inflammation of the mucous membranes of the oral cavity, including the buccal mucosa, palate, gingiva tongue, and lips.
Pharyngitis is one of the most common reasons for sick visits to the pediatrician's office or other outpatient acute care settings. An estimated 6.5 million outpatient visits are made annually for evaluation of pharyngitis among children and young adults younger than age 21,1 making this illness the third or fourth most common reason for seeking acute care in these age groups. Most episodes of pharyngitis are caused by viruses and require only supportive care. Up to 30% of acute pharyngitis episodes in children are attributable to group A beta-hemolytic streptococci (GABHS) with a peak incidence in winter and early spring.2 GABHS frequently colonize the oropharynx of asymptomatic children (5–20%), so that recovery of GABHS by culture or rapid detection techniques does not necessarily confirm true streptococcal pharyngitis.3
GABHS pharyngitis is most common among young school-age children. Streptococcal pharyngitis carries a potential significance exceeding the limited morbidity of throat discomfort, since GABHS pharyngitis may trigger significant nonsuppurative complications such as acute rheumatic fever and acute glomerulonephritis. Over the last two decades, there has been a relative resurgence of acute rheumatic fever in scattered regions in the United States, particularly in the Rocky Mountains and intermountain areas, with approximately 600 cases diagnosed in Salt Lake City, UT, between 1995 and 2003.4 This increase has brought increasing attention to the problem of streptococcal pharyngitis in the United States, although in much of the developing world, acute rheumatic fever has remained a widespread and serious clinical challenge.
GABHS are consistently detected either by rapid antigen detection testing (RADT)5 or by the presence of beta-hemolysis and susceptibility to bacitracin following culture on blood agar plates. There is marked molecular heterogeneity among GABHS isolates. Serologic methods used to type surface proteins (e.g., M, T) have been replaced over the past decade by genotyping based on sequence analysis of the corresponding emm gene that has defined over 100 unique emm genotypes. Such strain characterization has shown that several distinct GABHS strains may circulate within a community at a particular time. The predominant circulating strains may vary both temporally and geographically within the United States.6
Recurrent GABHS pharyngitis may be either due to acquisition of a new emm type or, less commonly, due to recurrence of a previously invasive strain. Recurrent streptococcal pharyngitis is a relatively common clinical problem, especially among children entering school. The overall incidence of recurrent GABHS pharyngitis in children is approximately 1% though there is substantial variation by age. Approximately ...