Sore Throat

Tonsillopharyngitis is predominantly a viral infection; a lesser number of cases are caused by bacteria.

The respiratory viruses (rhinovirus, adenovirus, the influenza virus, coronavirus, respiratory syncytial virus) are the most common viral causes, but occasionally Epstein-Barr virus (the cause of mononucleosis), herpes simplex, cytomegalovirus, HIV (as a primary infection), or coronavirus SARS-CoV-2 (the cause of COVID-19) is involved.

Strep Pharyngitis

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BIOPHOTO ASSOCIATES/SCIENCE PHOTO LIBRARY

The main bacterial cause of sore throat is group A beta-hemolytic streptococci (GABHS), which, although estimates vary, causes perhaps 10 to 25% of all sore throats in adults and slightly more in children. GABHS is a concern because serious poststreptococcal sequelae (eg, rheumatic fever, glomerulonephritis, abscess) may occur.

Uncommon bacterial causes include gonorrhea, diphtheria, mycoplasma, and chlamydial infection.

Peritonsillar Abscess With Uvular Deviation

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DR P. MARAZZI/SCIENCE PHOTO LIBRARY

Peritonsillar Abscess

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Image provided by Clarence T. Sasaki, MD.

An abscess in the pharyngeal area (peritonsillar, parapharyngeal, and, in children, retropharyngeal) is uncommon but causes significant throat pain. The usual causative organism is GABHS.

Epiglottitis, perhaps better termed supraglottitis, used to occur primarily in children and usually was caused by Haemophilus influenzae type B (HiB). Now, because of widespread childhood vaccination against HiB, supraglottitis/epiglottitis has been almost eradicated in children; more cases occur in adults. Causal organisms in children and adults include Streptococcus pneumoniae, Staphylococcus aureus, nontypeable H. influenzae, Haemophilus parainfluenzae, beta-hemolytic streptococci, Branhamella catarrhalis, and Klebsiella pneumoniae. HiB is still a cause in adults and unvaccinated children.

History of present illness should note the duration and severity of sore throat.

Review of systems should seek important associated symptoms, such as runny nose, cough, and difficulty swallowing, speaking, or breathing. The presence and duration of any preceding weakness and malaise (suggesting mononucleosis) are noted.

Past medical history should seek history of previous documented mononucleosis (recurrence is highly unlikely). Social history should include inquiring about close contact with people with documented GABHS infection, risk factors for gonorrhea transmission (eg, recent oral-genital sexual contact), and risk factors for HIV acquisition (eg, unprotected intercourse, multiple sex partners, IV drug abuse).

General examination should note fever and signs of respiratory distress, such as tachypnea, dyspnea, stridor, and, in children, the tripod position (sitting upright, leaning forward with neck hyperextended and jaw thrust forward).

During direct pharyngeal examination, erythema, exudates, and any signs of swelling around the tonsils or retropharyngeal area should be noted. Whether the uvula is in the midline or appears pushed to one side should also be noted.

If supraglottitis/epiglottitis is suspected and if patients (particularly children) have stridor, pharyngeal examination should be done cautiously because it, particularly when a tongue blade is inserted, may trigger complete airway obstruction. Ideally, examination should be done in an operating room and with a flexible fiberoptic laryngoscope,. Adults with no respiratory distress may be examined but also with care.

The neck is examined to check for enlarged, tender lymph nodes. The abdomen is palpated to check for splenomegaly, which may occur in patients with mononucleosis.

The following findings in patients with a sore throat are of particular concern:

• Stridor or other sign of respiratory distress

• Drooling

• Muffled, “hot potato” voice

• Visible bulge in the pharynx

Supraglottitis/epiglottitis and pharyngeal abscess pose a threat to the airway and must be differentiated from simple tonsillopharyngitis, which is uncomfortable but not acutely dangerous. Clinical findings help make this distinction.

With supraglottitis/epiglottitis, severe throat pain and dysphagia begin abruptly, usually with no preceding upper respiratory infection (URI) symptoms. Children often drool and have signs of toxicity. Sometimes (more often in children), patients have respiratory manifestations, with tachypnea, dyspnea, stridor, and sitting in the tripod position. If examined, the pharynx almost always appears unremarkable.

Pharyngeal abscess and tonsillopharyngitis may cause pharyngeal erythema, exudate, or both. However, some findings are more likely to occur in one condition or the other:

• Pharyngeal abscess: Muffled, “hot potato” voice (speaking as if a hot object is being held in the mouth) and visible focal swelling in the posterior pharyngeal area (often with deviation of the uvula)

• Tonsillopharyngitis: Often URI symptoms (eg, runny nose, cough)

Although tonsillopharyngitis is easily recognized clinically, its cause is not. Manifestations of viral and GABHS infection overlap significantly, although URI symptoms are more common with a viral cause. In adults, clinical criteria that increase suspicion of GABHS as a cause include

• Tonsillar exudate

• Tender lymphadenopathy

• Fever or history of fever

• Absence of cough

Adults with 1 or no criteria may reasonably be presumed to have viral illness. If ≥ 2 criteria are present, the likelihood of GABHS is high enough to warrant testing (1) but probably not high enough to warrant antibiotics, but this decision needs to be patient-specific (ie, threshold for testing and treatment may be lower in those at risk because of diabetes or immunocompromise). In children, testing usually is done. Although this approach is reasonable, not all experts agree on when to test for GABHS and when antibiotic treatment is indicated.

Rarer causes of tonsillopharyngitis should be considered when the following are present:

• Posterior cervical or generalized adenopathy, hepatosplenomegaly, and fatigue and malaise present for > 1 week: Infectious mononucleosis

• No URI symptoms but possible recent oral-genital contact: Pharyngeal gonorrhea

• A dirty-gray, thick, tough membrane on the posterior pharynx that bleeds if peeled away: Diphtheria (rare in the United States)

• Risk factors for HIV infection: HIV infection

If supraglottitis/epiglottitis is considered possible after evaluation, specific testing is required. Patients who do not appear seriously ill and have no respiratory symptoms may have plain lateral neck x-rays to look for edematous epiglottis. However, these x-rays are subject to false-positive interpretation because patient positioning may be imperfect (not a perfectly lateral view) or the x-ray is taken during expiration. Also, a child who appears seriously ill or has stridor or any other respiratory symptoms should not be transported to the x-ray suite. Such patients (and those with positive or equivocal x-ray findings) should usually have flexible fiberoptic laryngoscopy. (CAUTION: Examination of the pharynx and larynx may precipitate complete respiratory obstruction in children, and the pharynx and larynx should not be directly examined except in the operating room, where the most advanced airway intervention is available.)

Many abscesses are managed clinically, but if location and extent are unclear, immediate CT of the neck should be done.

In tonsillopharyngitis, throat culture is the most reliable way to differentiate viral infection from GABHS. To balance timeliness of diagnosis, cost, and accuracy, one strategy in children is to do a rapid strep screen in the office and treat if positive, and if negative, send a formal culture to a laboratory for testing. In adults, because other bacterial pathogens may be involved, throat culture for all bacterial pathogens is appropriate for those meeting clinical criteria described previously (tonsillar exudate, tender lymphadenomegaly, fever or history of fever, absence of cough).

Testing for mononucleosis, gonorrhea, or HIV infection is done only when clinically suspected.

1. 1. Fine AM, Nizet V, Mandl KD: Large-scale validation of the Centor and McIsaac scores to predict group A streptococcal pharyngitis. Arch Intern Med 172 (11):847–852, 2012. doi:10.1001/archinternmed.2012.950