• University of Michigan Health System. Pharyngitis. Ann Arbor (MI): University of Michigan Health System; 2006 Oct. 10 p. [9 references]

This is the current release of the guideline.

This guideline updates a previous version: Pharyngitis. Guidelines for clinical care. Ann Arbor (MI): University of Michigan Health System; 2000 Dec. 8 p.

Pharyngitis

Diagnosis
Evaluation
Management
Treatment

Family Practice
Internal Medicine
Pediatrics

Advanced Practice Nurses
Nurses
Physician Assistants
Physicians

• To utilize signs and symptoms to determine pretest probability of Group A beta hemolytic streptococcal (GABHS) pharyngitis
• To confirm all negative results with culture in patients <16 years old where GABHS pharyngitis is suspected and a rapid strep screen is performed
• To reduce indiscriminate use of antibiotics to minimize potential adverse effects
• To assure appropriate course of antibiotic treatment to prevent rheumatic fever and suppurative complications (e.g., otitis media, sinusitis, peritonsillar/retropharyngeal abscesses or mastoiditis)
• To hasten illness resolution and reduction in transmission of GABHS pharyngitis to others

Patients 3 years old through adulthood with a sore throat

Diagnosis

1. Evaluation of signs/symptoms of Group A beta hemolytic streptococcal disease (GABHS)
2. Use of algorithms to improve diagnostic accuracy
3. Laboratory confirmation of GABHS
4. Throat culture
5. Rapid streptococcal antigen tests
6. Phone triage for GABHS symptoms when clinic access is a problem

Treatment

1. Antibiotic treatment (penicillin, amoxicillin, erythromycin, azithromycin, narrow spectrum oral cephalosporin [e.g., cephalexin])

• Diagnostic accuracy
• Rate of prescription of antibiotics
• Symptomatic improvement (i.e., symptom scores)
• Overall duration of symptoms (days)
• Eradication of Group A beta hemolytic streptococcal disease (GABHS)
• Incidence of acute rheumatic fever
• Cost effectiveness
• Adverse effects of antibiotic use, including allergic reaction, emergence of resistant strains of GABHS

Hand-searches of Published Literature (Primary Sources)
Searches of Electronic Databases

The literature search for this update began with the results of the literature search performed for the 2000 version of this guideline. A search for literature published since that time was performed. The search on Medline was conducted prospectively for literature published from 7/1/00 to 5/30/05 using the major keywords of: GABHS pharyngitis (streptococcal infections, Streptococcus pyogenes, pharyngitis, pharynx), strep throat; human; English; guidelines; controlled trials. Searches were performed separately for children, for adults, and for age not specified for the following specific topics: history, physical exam, signs, symptoms, throat culture (strep culture), rapid strep screen, observation, antibiotics, other treatment/management, and other references. Specific search terms and strategy are available upon request.

The search was conducted in components each keyed to a specific causal link in a formal problem structure (available upon request). The search was supplemented with recent clinical trials known to expert members of the panel. Negative trials were specifically sought. The search was a single cycle.

Not stated

Weighting According to a Rating Scheme (Scheme Given)

Levels of evidence for the most significant recommendations:

1. Randomized controlled trials
2. Controlled trials, no randomization
3. Observational trials
4. Opinion of expert panel

Systematic Review

Conclusions were based on prospective randomized clinical trials (RCTs) if available, to the exclusion of other data. If RCTs were not available, observational studies were admitted to consideration. If no such data were available for a given link in the problem formulation, expert opinion was used to estimate effect size.

Expert Consensus

Not stated

Not applicable

Published cost-analyses were reviewed.

Internal Peer Review

University of Michigan Health System (UMHS) guidelines are reviewed by clinical conferences of physicians in departments to which the content is most relevant and by leadership in those departments/divisions. This guideline concerning pharyngitis was reviewed by members of the following departments: General Pediatrics; General Medicine; Family Medicine, Pediatric Infectious Diseases.

Guidelines are approved by the Executive Committee of Clinical Affairs (ECCA).

Note from the National Guideline Clearinghouse (NGC): The following key points summarize the content of the guideline. Refer to the full text for additional information including specific information on drug dosing and costs.

The levels of evidence [A-D] are defined at the end of the "Major Recommendations."

General Principals

• Viral agents cause most cases of pharyngitis: around 90% in adults and 70% in children [C].
• The prime reason to identify and treat Group A beta hemolytic streptococcal (GABHS) pharyngitis is to decrease the risk of acute rheumatic fever (ARF) [A]. The endemic incidence of ARF is around 0.23 to 1.88/100,000.
• Early treatment of GABHS can decrease the time a patient is symptomatic by 1 to 2 days from a typical 3 to 7 days [A] and may decrease the period of contagiousness [C]

Diagnosis

• Signs/symptoms of recent fever, tender anterior cervical lymphadenopathy, red pharynx +/- tonsillar swelling or exudate, and no cough indicate a higher probability of GABHS for both adults and children. Algorithms incorporating epidemiologic and clinical factors improve diagnostic accuracy primarily by identifying patients with an exceedingly low risk of streptococcal infection [C].
• Laboratory confirmation: Test when diagnosis is not ruled out by viral symptoms (see table below).
  • For adults: confirmation is most useful when GABHS is suspected; however, only test those with at least 2 or more signs/ symptoms mentioned above. [C].
  • For patients between 3 to 15 years of age: confirmation is most useful when GABHS cannot be excluded. Nevertheless, only test those with at least 1 or more signs/symptoms mentioned above [C]. The threshold for testing is lower for children because their risk of developing acute rheumatic fever is higher.

Signs and Symptoms

• Throat culture is the presumed "gold standard" for diagnosis [C]. Rapid streptococcal antigen tests identify GABHS more rapidly, but have variable sensitivity [C].
  • Reserve rapid strep tests for patients with a reasonable probability of having GABHS. In patients screened with a rapid strep test, a negative result should be confirmed by culture in patients <16 years old (and considered in parents or siblings of school age children) due to their higher incidence of developing acute rheumatic fever [C].
  • If screening for GABHS in very low risk patients is desired, culture alone is cost effective.

Treatment

• Penicillin is the drug of choice in patients who can swallow pills. If suspension must be prescribed, amoxicillin is better tolerated due to the extremely bitter taste of penicillin.
  • Erythromycin is preferred for patients allergic to penicillin.
  • For patients expected to be intolerant or non-compliant with an erythromycin product (e.g., younger patients), consider azithromycin or a narrow spectrum oral cephalosporin like cephalexin.
• Antibiotic treatment must be started within 9 days after onset of the acute illness and continued for 10 days (or 5 days for azithromycin) to eradicate GABHS from the upper respiratory tract and prevent acute rheumatic fever [D].

Controversial Areas

Based on a description over the phone, a clinician may decide to screen or treat for GABHS [D]:

• When clinic access is a problem (e.g., during flu season), one may elect to have a staff member triage symptoms for GABHS screening.
• When a symptomatic patient is >3 years old and has a family member recently documented by lab testing to have GABHS pharyngitis, one may elect to treat without screening.

Definitions:

Levels of evidence for the most significant recommendations:

1. Randomized controlled trials
2. Controlled trials, no randomization
3. Observational trials
4. Opinion of expert panel

Algorithms are provided in the original guideline document for:

• Adult pharyngitis (Patients >16 years old)
• Pediatric pharyngitis (Patients 3 to 15 years old)

Conclusions were based on prospective randomized clinical trials (RCTs) if available, to the exclusion of other data; if RCTs were not available, observational studies were admitted to consideration. If no such data were available for a given link in the problem formulation, expert opinion was used to estimate effect size. The type of evidence is identified and graded for the most significant recommendations (see "Major Recommendations").

• The prime reason to identify and treat group A beta-hemolytic streptococcal (GABHS) pharyngitis is to decrease the risk of acute rheumatic fever.
• Early treatment of GABHS shortens the clinical course, may reduce the risk of transmission, and may decrease the risk of other suppurative sequela (e.g., otitis media, sinusitis, peritonsillar/retropharyngeal abscesses or mastoiditis).
• Rational use of antibiotics contains cost and prevents harms associated with indiscriminate antibiotic use, including increased incidence of allergic reactions to antibiotics, increased incidence of mislabeling patients as allergic to antibiotics, and the emergence of resistant strains of GABHS pharyngitis or other pathogenic bacteria.

• The value of early diagnosis in the minority of cases when strep is present and identified must be weighed against the higher total laboratory charges for the majority of cases screened. Most screens are negative and additional charges will be incurred for a subsequent culture.
• Antibiotic side effects may include rash, nausea, abdominal pain, and/or diarrhea. A single intramuscular injection of benzathine penicillin produces a significant amount of pain at the injection site that may last a number of days, as well as increased risk of anaphylaxis.

The antibiotic rifampin is relatively contraindicated for pregnant women.

These guidelines should not be construed as including all proper methods of care or excluding other acceptable methods of care reasonably directed to obtaining the same results. The ultimate judgment regarding any specific clinical procedure or treatment must be made by the physician in light of the circumstances presented by the patient.

An implementation strategy was not provided.

Getting Better

Effectiveness
Patient-centeredness

• University of Michigan Health System. Pharyngitis. Ann Arbor (MI): University of Michigan Health System; 2006 Oct. 10 p. [9 references]

Not applicable: The guideline was not adapted from another source.

1996 Nov (revised 2006 Oct)

University of Michigan Health System - Academic Institution

University of Michigan Health System

Pharyngitis Guideline Team

Team Leader: Terrance P Murphy, MD, Pediatrics

Team Members: R Van Harrison, PhD, Medical Education; Annissa J Hammoud, MD, Internal Medicine-Pediatrics; Gary Yen, MD, Family Medicine

Consultants: R Alexander Blackwood, MD, PhD, Pediatric Infectious Diseases; John R Crump, MD, General Internal Medicine

Guidelines Oversight Team: Connie Standiford, MD; William E Chavey, MD; R Van Harrison, PhD

None of the members of the Pharyngitis guideline team have a relationship with commercial companies whose products are discussed in this guideline. The team members are listed on the front page of the guideline document.

This is the current release of the guideline.

This guideline updates a previous version: Pharyngitis. Guidelines for clinical care. Ann Arbor (MI): University of Michigan Health System; 2000 Dec. 8 p.

This summary was completed by ECRI on May 20, 1999. The information was verified by the guideline developer on June 17, 1999. This summary was updated by ECRI on December 14, 2001. The updated information was verified by the guideline developer as of February 8, 2002. This summary was updated by ECRI Institute on April 23, 2007. The updated information was verified by the guideline developer on April 25, 2007.

This NGC summary is based on the original guideline, which is copyrighted by the University of Michigan Health System (UMHS).