• 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.

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").

• 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).