Pharyngitis: Approach to diagnosis and treatment

Abstract

Objective: To provide family physicians with an updated approach to diagnosis and treatment of pharyngitis, detailing key symptoms, methods of investigation, and a summary of common causes.

Sources of information: The approach described is based on the authors' clinical practice and peer-reviewed literature from 1989 to 2018.

Main message: Sore throat caused by pharyngitis is commonly seen in family medicine clinics and is caused by inflammation of the pharynx and surrounding tissues. Pharyngitis can be caused by viral, bacterial, or fungal infections. Viral causes are often self-limiting, while bacterial and fungal infections typically require antimicrobial therapy. Rapid antigen detection tests and throat cultures can be used with clinical findings to identify the inciting organism. Pharyngitis caused by Streptococcus pyogenes is among the most concerning owing to its associated severe complications such as acute rheumatic fever and glomerulonephritis. Hence, careful diagnosis of pharyngitis is necessary to provide targeted treatment.

Conclusion: A thorough history is key to diagnosing pharyngitis. Rapid antigen detection tests should be reserved for concerns about antibiotic initiation. Physicians should exercise restraint in antibiotic initiation for pharyngitis, as restraint does not delay recovery or increase the risk of S pyogenes infections.

Figure 1.

Key physical findings in the oropharynx in viral, bacterial, and fungal pharyngitis

Figure 2.

Modified Centor scoring system: Used to calculate the risk of streptococcal pharyngitis and to decide whether RADT and antimicrobial therapy should be initiated in patients presenting with sore throat. Clinicians should consider performing RADT for those with scores of 2 if they are pediatric patients, if they are at risk of complications (immunocompromised or frail), or if they appear clinically unwell. GAS—group A streptococcus, RADT—rapid antigen detection testing. ^*The decision matrix has been defined for ages 5–14 y, as those aged younger than 3 y require backup validation with throat culture regardless of scoring. Values from McIsaac et al.

Figure 3.

FeverPAIN scoring system: Developed in the United Kingdom for calculating the risk of streptococcal pharyngitis in patients presenting with sore throat. Scores can be further used to decide when antimicrobial therapy versus follow-up is warranted. GAS—group A streptococcus. Values from Little et al.

Figure 4.

Generalized approach to pharyngitis: Antimicrobial therapy should be initiated in patients who are severely ill or who are highly suspected of having streptococcal infections. Modified Centor and FeverPAIN scores of < 3 should be treated symptomatically with possible follow-up for worsening symptoms or delayed prescription if there are concerns about loss to follow-up. Those at risk of complications (elderly, frail, immunocompromised) might benefit from RADT to rule out bacterial causes. Severely ill patients should be referred immediately to the hospital or urgent care for immediate management and workup. RADT—rapid antigen detection testing. Adapted from the National Institute for Health and Care Excellence.