Pharyngitis diagnostic study of choice

Overview

Diagnostic tests provided include throat culture and checking for rapid antigen detection. Although the sensitivity and specificity of rapid antigen detection testing have improved dramatically, a throat culture is considered the diagnostic standard. It is possible to use the adjusted Centor score to help doctors determine which patients do not need testing, throat culture/rapid antigen detection testing, or empirical antibiotic therapy.

Diagnostic Study of Choice

Study of choice

The diagnostic study of choice for bacterial pharyngitis is the throat culture. A single-swab throat culture is 90 to 95 percent sensitive with proper sampling and plating techniques.

The comparison of various diagnostic studies for bacterial pharyngitis

Test	Sensitivity	Specificity
Test 1	...%	...%
Test 2	...%	...%

[Name of test with higher sensitivity and specificity] is the preferred investigation based on the sensitivity and specificity

Diagnostic results

The following finding(s) on performing [investigation name] is(are) confirmatory for [disease name]:

• [Finding 1]
• [Finding 2]

Sequence of Diagnostic Studies

The [name of investigation] must be performed when:

• The patient presented with symptoms/signs 1, 2, and 3 as the first step of diagnosis.
• A positive [test] is detected in the patient, to confirm the diagnosis.

OR

The various investigations must be performed in the following order:

• [Initial investigation]
• [2nd investigation]

Centor criteria
The original Center score uses four signs and symptoms to estimate the probability of acute streptococcal pharyngitis in adults with a sore throat The score was later modified by adding age. It is important to evaluate for a definitive diagnosis to exclude GAS and to avoid unnecessary lab tests and antibiotic use. Centor criteria are a widely used and accepted clinical decision tool in identifying patients for whom neither microbiologic tests nor antimicrobial therapy is necessary. The Center score to use for children and adults with a sore throat to estimate the probability of Streptococcus pyogenes infection.

Modified Centor criteria			Appropriate management according to the total score
Criteria	Points		Total score	Chance of streptococcal infection in community with usual levels of infection, %	Suggested management
Fever (temperature > 38°C)	+1		0	2-3%	No culture or antibiotic is required
Absence of cough	+1		1	4-6%
Swollen and tender anterior cervical nodes	+1		2	10-12%	RADT or Culture and treat only if culture result is positive
Tonsillar swelling or exudates	+1		3	27-28%
Age 3–14 yr	+1		4	38–63%	Culture all and treat emperically with penicillin on clinical grounds
Age 15–44 yr	0
Age ≥ 45 yr	-1

Name of Diagnostic Criteria

It is recommended that you include the criteria in a table. Make sure you always cite the source of the content and whether the table has been adapted from another source.

[Disease name] is primarily diagnosed based on clinical presentation. There are no established criteria for the diagnosis of [disease name].

OR

There is no single diagnostic study of choice for [disease name], though [disease name] may be diagnosed based on [name of criteria] established by [...].

OR

The diagnosis of [disease name] is made when at least [number] of the following [number] diagnostic criteria are met: [criterion 1], [criterion 2], [criterion 3], and [criterion 4].

OR

The diagnosis of [disease name] is based on the [criteria name] criteria, which includes [criterion 1], [criterion 2], and [criterion 3].

OR

[Disease name] may be diagnosed at any time if one or more of the following criteria are met:

• Criteria 1
• Criteria 2
• Criteria 3

OR

IF there are clear, established diagnostic criteria

The diagnosis of [disease name] is made when at least [number] of the following [number] diagnostic criteria are met: [criterion 1], [criterion 2], [criterion 3], and [criterion 4].

OR

The diagnosis of [disease name] is based on the [criteria name] criteria, which include [criterion 1], [criterion 2], and [criterion 3].

OR

The diagnosis of [disease name] is based on the [definition name] definition, which includes [criterion 1], [criterion 2], and [criterion 3].

OR

IF there are no established diagnostic criteria

There are no established criteria for the diagnosis of [disease name].