A Young Man with a Severe Sore Throat

A 21-year-old male college senior presents for evaluation and treatment of a severe sore throat of 2-day duration. His sore throat has worsened over time such that it is interfering with his studying regimen for upcoming finals. He has not experienced any symptoms of upper respiratory infection (eg, rhinorrhea or cough), however, he has had the sensation of fevers. He is otherwise in excellent health.  

He had gone to a an urgent care center where a polymerase chain reaction (PCR) test was performed and was negative for group A streptococcus, but his symptoms had not abated in the last 36 hours.

Physical Examination

The patient was a well-developed young man with a degree of facial flushing. His temperature was 101.6 F°. Pharynx exam revealed inflamed tonsils with exudates. Uvula was midline. He had bilateral tender cervical adenopathy. Chest was clear without wheezes, rales, or consolidation.

Which of the following is the most accurate answer regarding this patient’s situation?

A. The negative group A streptococcus PCR assay essentially excludes a bacterial sore throat.
B. The combination of a high Centor Score with negative strep PCR is an indication for multiple agent, nonpenicillin antibiotic
     treatment.
C. The patient is at high risk for a variety of supporative complications.
D. Additional microbiologic testing is indicated and if treatment empirically prescribed, penicillin should be used.

(Answer and discussion on next page)

Correct Answer: D

Primary care practitioners commonly see patients who present with a sore throat.  Although viral sore throats are by far the most common, bacterial sore throats are important as they can cause supporative complications—and, at the same time, remain quite amenable to relatively easy antibiotic treatments.¹ The Centor Score is a well-validated clinical tool that can be used to stratify the risk of a sore throat being bacterial and enrich the yield for using the rapid PCR detection for group A streptococci to confirm the need for antibiotics.^1,2 The Centor Scoring system applies 1 point each for history of fever, absence of cough, tender cervical lymphadenopathy, and tonsillar exudates. A score ≤1 means bacterial infection is unlikely, while a ≥2 should prompt rapid antigen testing and resultant antibiotic treatment.^2,3

Of note, recent epidemiologic studies have demonstrated that the Fusobacterium necrophorum organism is an important etiology in bacterial sore throat, even higher in incidence (20.5% vs 10.3%, respectively) in the group of adolescents and young adults in comparison to younger pediatric patients.⁴ This organism is not detected in the routine PCR antigen assays currently being used. 

A recent study found that, as with streptococcal sore throat, there is also a good correlation with Centor Score and detecting F necrophorum using anaerobic culture and/or specialized PCR testing techniques.⁴ Of note, neither of these is routinely available for clinical use (although anaerobic testing can be done in most hospital labs when requested).

Note: F necrophorum is quite capable of causing dangerous supporative complications and, in fact, is the most common cause of peritonsillar abscess in adolescents and young adults, and the primary cause in up to 80% of the Lemmiere syndrome.^1,4 Happily, F necrophorum is usually susceptible to penicillin and first-generation cephalosporins in most cases.

Treatment

Taking all of these studies and facts into account allows a proposed strategy in the approach to a serious, high Centor Score sore throat.

As alluded to in the discussion, a negative standard group A strep PCR assay does not exclude a bacterial sore throat (other causative organisms beside F necrophorum also include other nongroup A streptococci and Mycoplasma pneumoniae) making Answer A incorrect.

It appears that in adolescents and young adults, F necrophorum is the major nonstrep A causative microbe in bacterial sore throats and is usually susceptible to penicillin such that multiple agent nonpenicillin antibiotics are not required either empirically or even if the organism is subsequently identified; thus, Answer B is incorrect.

Although F necrophorum seems to be a leading cause for the feared and serious supporative complications of bacterial sore throat, such complications remain uncommon and are estimated at 1 in 400 cases.^1,3 Therefore, Answer C is an overstatement and incorrect.

In our case, the patient had a Centor Score of 4 and did not improve within 36 to 48 hours. A bacterial sore throat was likely. A rapid PCR diagnostic test for strep A had been performed and was negative. Thus, another organism not detected by that test is likely; by the patient’s age, F necrophorum is most likely the culprit and empiric therapy with penicillin is a reasonable treatment option. Therefore, the correct statement here is Answer D.

Outcome of the Case

Since the patient had no improvement in his clinical status, additional testing involving aerobic and anaerobic culture of throat swabs was performed and the patient was started on oral penicillin. Within 24 hours, he noted prompt improvement with resolution of fever and sore throat. Culture results were positive for F necophorum sensitive to penicillin. He completed a 10-day antibiotic treatment without incident and with full recovery.

Ronald Rubin, MD, is a professor of medicine at Temple University School of Medicine and chief of clinical hematology in the department of medicine at Temple University Hospital, both in Philadelphia, PA. 

References:

1. Linder AL. Sore throat: avoid overcomplicating the uncomplicated. Ann Intern Med. 2015;162(4):311-312.
2. Fine AM, Nizet V, Mandl KD. Large-scale validation of the Centor and McIsaac scores to predict group A streptococcal pharyngitis. Arch Intern Med. 2012;172(11):847-852.
3. Centor RM. Expand the pharyngitis paradigm for adolescents and young adults. Ann Intern Med. 2009;151(11):812-815.
4. Centor RM, Atkinson TP, Ratliff AE, et al. The clinical presentation of Fusobacterium-positive pharyngitis and streptococcal-positive pharyngitis in a university health clinic. A cross-sectional study. Ann Intern Med. 2015;162(4):241-247.