Early treatment of streptococcal pharyngitis

Evaluation of the patient with sore throat, earache, and sinusitis: an evidence based approach

Sore throat, earache, and sinusitis are common presenting complaints in the emergency department, and all fall within the top ten in the United States. These complaints usually have a benign course but rarely can be a symptom of a serious disease process. This article provides an evidence-based review of the literature regarding the diagnosis of pharyngitis, otitis media, and sinusitis.

Comparison of ambulance dispatch protocols for nontraumatic abdominal pain

STUDY OBJECTIVE

To compare rates of undertriage and overtriage of six ambulance dispatch protocols for the presenting complaint of nontraumatic abdominal pain, and to identify the optimal protocol.

DESIGN

Retrospective prehospital and emergency department chart review to classify patients' conditions as "emergency" or "nonemergency." Utility analysis was used to identify the preferred protocol and monetary cost-effectiveness analysis to identify the least expensive protocol.

SETTING

County emergency medical services (EMS) system with five receiving hospitals serving a mainly urban population of approximately 350,000.

PARTICIPANTS

Records of 902 patients who called 911 for nontraumatic abdominal pain were reviewed; patients not transported were excluded. Twenty-seven county EMS medical directors completed questionnaires.

RESULTS

Six ambulance dispatch protocols for nontraumatic abdominal pain were developed: indiscriminate-dispatch, four selective protocols, and no-dispatch. A dichotomous classification system was derived prospectively from the prehospital and medical records of patients who had activated the EMS system before the study period to define "emergency" and "nonemergency" conditions associated with nontraumatic abdominal pain. Emergency criteria identified patients with conditions requiring medical treatment within 1 hour. Reviewers determined, for each patient, whether an ambulance would have been dispatched by each of the protocols. Undertriage and overtriage rates were calculated for each protocol. County EMS medical directors assigned utility values to four potential outcomes of ambulance dispatch by the direct scaling method. The outcomes comprised correct and incorrect decisions to dispatch ambulances to patients with and without emergencies. The protocols were compared by decision analysis. A cost analysis was also performed, using an estimated marginal cost per transport of $302. Sensitivity analysis demonstrated the effect of varying the cost of an undertriage error and the cost per response. Of the 788 patients included in the study, 7.8% had conditions defined as emergencies. The four selective ambulance dispatch protocols had overtriage rates ranging from 10% to 51% and undertriage rates of 4% to 7%. None of the protocols was proven superior on the basis of the medical directors' assignment of utility values. The marginal cost of dispatching advanced life support ambulances to all patients with this complaint was $3,838 per emergency.

CONCLUSION

The majority of patients with nontraumatic abdominal pain who requested ambulance transport during the study period did not have conditions that were classified as emergencies. In the study model, if an undertriage error costs more than $3,674, indiscriminate ambulance dispatch is the least expensive protocol, and if an undertriage error costs less than $3,674, no ambulance dispatch is the least expensive strategy.

Streptococcal pharyngitis: a review of pathophysiology, diagnosis, and management

Pharyngitis is an illness frequently treated by emergency physicians and primary care practitioners. It is the subject of much controversy regarding optimal treatment in the acute care setting. This review discusses pertinent aspects of the pathophysiology, clinical features, diagnosis, and treatment based on available literature. This review is also meant to serve as a bibliographic resource for some of the controversies of this complex topic.

The impact of a rapid screen for streptococcal pharyngitis on clinical decision making in the emergency department

The impact of a rapid streptococcal screening test (RSS) on clinical decision making in the management of patients with acute pharyngitis was evaluated. Physicians managing 95 ambulatory patients with the complaint of sore throat were asked to estimate the probability of group A beta-hemolytic streptococcal pharyngitis (GRABS) in each patient and whether they intended to treat with antibiotics both before and after the results of the RSS were known. Simultaneous throat cultures were obtained for 80 patients at the discretion of the treating physicians. Regression analysis revealed that the RSS result was an important independent predictor for the posttest decision to treat with antibiotics and for the estimated probability of disease. The mean absolute log-likelihood ratio was used to quantify the effect of the RSS on diagnostic certainty; a greater contribution to diagnostic certainty occurred when the RSS was positive. Physicians would have prescribed an antibiotic 49 times without the benefit of the RSS and prescribed an antibiotic 48 times given the RSS result. Without the RSS, the treatment decision contradicted the throat culture result in 25 cases. With the RSS, this occurred in 26 cases. The RSS, while influencing decision making, especially when positive, did not decrease the use of antibiotics.

What a difference a day makes: a decision analysis of adult streptococcal pharyngitis

With the availability of group A beta-hemolytic streptococcal (GABHS) antigen detection tests, the management of adult pharyngitis is being reassessed. A decision analytic model was developed which considered four strategies: immediate treatment, no treatment, performing a rapid antigen test, or obtaining a bacterial culture. Patient outcomes were expressed in "well" days, which were reduced by the "sick" days associated with adverse reactions to treatment or complications of GABHS infection. When immediate test results are available, testing is the optimal strategy for probabilities of GABHS between 1 and 49 per cent. This range includes almost all patients, using probability estimates based on clinical criteria. The absolute benefit of testing was 0.1 days. The major advantage of a rapid test is the avoidance of penicillin reactions. Variations in the symptomatic benefits of treatment had minimal effects on the analysis. The analysis supports the use of an antigen test for adult patients with pharyngitis.

Non-sexually transmitted infectious diseases of the oral, nasal, and vaginal mucosae

The skin and mucous membranes are the principal barriers to invasion of the body by microorganisms. Besides functioning as a mechanical barrier, the mucosae are endowed with an array of still poorly characterized specific and nonspecific host defense capabilities. These include the production of mucus, secretory immunoglobulin (IgA), lysozyme, lactoferrin, and alpha-antitrypsin, in conjunction with a low-grade exudation of leukocytes.¹ In addition, the mucosal surfaces of the upper respiratory, gastrointestinal, and lower vaginal and urinary tracts support a large number of “nonpathogenic” microorganisms that comprise the so-called “normal flora.” This commensal flora plays an important and complex role in protecting the host from microbial invasion. Mechanisms for this protection likely include the following: (1) competition for the same nutrients (interference); (2) competition for the same receptors on host cells (tropism); (3) production of bacteriocins, that is, bacterial products that are toxic to other organisms, usually of the same species; and (4) stimulation of crossprotective immune factors such as the “natural antibodies.”¹

The “normal” flora is inconstant and may be altered by dietary factors, debilitation, hormonal events (such as menstruation, pregnancy, and possibly use of oral contraceptives), personal hygiene, medications, intercurrent infection, and probably many others. Antibiotic therapy and menstruation can have a profound effect on the composition of this group of microorganisms.² Disturbance of the delicate host-commensal relationship may cause a clinically significant infection due to these “nonpathogens.” This may occur in response to the aforementioned factors (eg, pregnancy predisposing to vaginal candidiasis) or because of disruption of the anatomic barrier (eg, local mucosal infection at a site of trauma, or injury from cytotoxic drugs) or in association with exogenous infection (eg, rhinoviral infection leading to secondary bacterial otitis media). Invasion by “normal flora” may result in serious systemic illness. A clear example of the latter is the development of infective endocarditis caused by viridans streptococci following a dental procedure.

Rapid diagnosis of streptococcal pharyngitis in adult emergency room patients

A rapid latex agglutination slide test for group A beta-hemolytic streptococcal throat infections was prospectively evaluated. Resident physicians, working in an adult non-acute emergency room, recorded clinical data and collected throat swabs from 729 adult patients with sore throats. Research assistants obtained throat swabs from 329 control patients. Sensitivity and specificity, compared with routine cultures, were 96% and 97%, respectively. Analyses of clinical predictions and of test results for control patients, however, suggest that this test may perform better than routine culture. The test provides a rapid, accurate, potentially useful alternative for diagnosing group A beta-hemolytic streptococcal pharyngitis in adults.

Streptococcal pharyngitis in the emergency department: analysis of therapeutic strategies

Potential streptococcal pharyngitis represents a common presenting complaint of patients in emergency departments. Studies have shown that therapy within the first 48 hours of presentation hastens the resolution of the infection. A prior analysis of the cost of treatment for potential streptococcal pharyngitis in an outpatient practice suggested that when the likelihood of a positive throat culture is high, therapy is more cost effective without a throat culture. The current analysis evaluates the effects of emergency department charges, incomplete follow-up, and several common screening tests (Gram stain, clinical scoring) upon the cost of treatment and the risk for rheumatic fever. The results of the current analysis support the use of common screening tests to permit immediate oral or parenteral penicillin treatment of selected patients without a throat culture and the use of a throat culture to detect false-negative screen results.

Sore throat: to culture or not to culture

The traditional use of the throat culture to guide treatment of potential streptococcal pharyngitis recently has been questioned because of the following facts: antibiotic therapy within the first 48 hours of illness reduces the severity and symptoms of streptococcal pharyngitis; more rapid treatment of streptococcal pharyngitis may be more effective in prevention of rheumatic fever; clinical and Gram stain criteria can identify individuals with a high probability of a positive throat culture; new latex agglutination tests can identify within minutes individuals with a high probability of a positive throat culture; the throat culture may be falsely negative in individuals with partially treated pharyngitis, an inadequately swabbed or plated specimen, or an improperly read culture plate; and incomplete patient followup increases the true societal cost of traditional therapy based on throat culture results. These issues suggest that a sufficiently accurate screening test for guiding antibiotic therapy at the initial visit may be more clinically beneficial and cost effective than recalling all positive throat culture patients for antibiotic therapy. Nonetheless, a throat culture remains important when a screening test of a patient with suspected streptococcal pharyngitis is negative. Indications for culturing pharyngitis for other potential pathogens also are discussed.

Rapid diagnosis of group A strep pharyngitis in the emergency department

Two ten-minute rapid tests for diagnosing Group A streptococcal pharyngitis in 147 emergency department patients with a complaint of sore throat were evaluated using positive throat cultures as the marker for disease. Treatment was initiated solely on the basis of clinical judgment. Sensitivity and specificity were 78% and 93%, respectively, for the rapid test and 69% and 56%, respectively, for clinical judgment. The rapid test was significantly better than clinical judgment alone in determining the presence of disease (P less than .05). The predictive values of the positive and negative and were 78% and 93%, respectively, for the rapid test and 38% and 85%, respectively, for clinical judgment. In the ED setting in which adequate followup is difficult, the rapid test can identify more accurately than can clinical judgment alone those patients who need therapy.