More Than Strep: Pharyngitis w/ “Uncle Bob” Centor

August 19, 2020 | By Justin Berk

The creator of the Centor score gives us an evidence-based discussion to the diagnosis and management of pharyngitis

Summary

Your kid’s got a sore throat–no big deal? Think again! Strep Up 2 the Streets and listen to this episode as we wade into the depths of pediatric and adolescent pharyngitis, with the world-renowned creator of the Centor Criteria Dr. Robert Centor MD, MACP, internist and Professor-Emeritus at The University of Alabama at Birmingham School of Medicine. In this episode, we discuss/review the Centor criteria, the differential diagnosis for acute pharyngitis in the school-aged versus adolescent patient, how to treat bacterial pharyngitis, and what complications to watch out for in the pediatric populations. 

Credits

Written and Produced by: Becca Raymond-Kolker
Infographic: Cleo Rochat, Becca Raymond-Kolker
Cover Art: Christopher Chiu MD
Hosts: Justin Berk MD and Christopher Chiu MD
Editor:Justin Berk MD; Clair Morgan of nodderly.com
Guest(s): Robert Centor MD

Time Stamps

Guest intro 1:30
Case from Kashlak Children’s 6:36
Acute Pharyngitis Definitions 7:15
Reasons for Treating Strep 13:00
Centor Score vs McIssac Score 15:45
Basic Management for GAS 22:00
Steroids for GAS? 23:55
GAS Complications 25:16
Adolescent Sore Throat 27:40
Lemierre’s Syndrome 30:28
Red Flags of Lemierre’s 34:30
Other Diagnoses in the Differential 36:08
Pharyngeal gonorrhea 40:50
Key Takeaways 44:00

Pharyngitis Pearls

1. The differential diagnosis for pharyngitis is very different in school-aged versus adolescent/young adult patients. 
2. If your patient has a Centor score of 0 or 1, you do not need to do a Rapid Strep test or give antibiotics.
3. Five + Potential Reasons to Treat Group A Strep
   1. Prevent Acute Rheumatic Fever 
   2. Decrease probability  of peritonsillar abscesses or other similar abscesses 
   3. Decrease spread in the household (If a 7 year old has GAS, untreated, at least 50% of the other people in the household will get in)
   4. Prevent death 
   5. To go back to school 
   6. For adolescents: shortening the duration of illness
4. Red Flags for Lemierre’s Syndrome:

• Rigors (high likelihood ratio for bacteremia)
• Unilateral neck swelling (either peritonsillar abscess or Lemierre’s)
• Pulmonary symptoms
• No improvement after 5-6 days

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Acute Pharyngitis

Definition of acute pharyngitis: 1 day to 3 days. Greater than a week is no longer acute pharyngitis. With or without treatment, especially in kids, most everyone is better in 3 – 5 days. 

Development of Centor Criteria

The original research that led to the development of the Centor criteria came from a walk-in Emergency Department with a lot of adolescents and young adults (15-30 year olds). Based on this data, the original score was not developed with the pediatric population in mind.

Discussion of the Centor Criteria

Guidelines agree we should not overtreat nor overtest children who have pharyngitis. The real value of the Modified/McIsaac Centor Score is telling you who to reassure. Sidenote: In the original study, the history of a fever was better than the actual temperature taken in the ER. Ask about cough and coryza, look for significant pus on tonsils and feel for anterior cervical adenopathy, both of which increase the probability of a bacterial infection.

Testing for Group A Strep

For the vast majority of children (school-aged), the only important bacterial cause of pharyngitis is Group A strep. However, there is also a significant carrier rate in this age range as well. If you do a rapid test on everybody, you will be giving a lot of antibiotics to kids who are just carriers. A low score will obviate the need to treat or do a test. Key takeaway: All guidelines (ACP, IDSA) state that if you have a score of 0 or 1, you do not need to do a test or give antibiotics. 

Should we treat GAS in children?

There is a discussion whether or not to even treat GAS in school-aged children. Dr. Centor discusses an article that argues that since the rate of Acute Rheumatic Fever in the US is so low, the risks associated with antibiotic use is worse than the risk of ARF. 

Five+ Potential Reasons to Treat Group A Strep 

1. Prevent Acute Rheumatic Fever 
2. Decrease probability of peritonsillar abscesses (or other similar abscesses)
3. Decrease spread in the household
   1. If 7 year old has GAS, untreated, at least 50% of the other people in the household will also get GAS
4. Prevent death (exceedingly rare, but there are reports of streptococcal shock syndrome from GAS)
5. To go back to school 

• For adolescents: shortening the duration of illness

Board exam Pearl: Post-Streptococcal Glomerulonephritis is a complication of GAS that is NOT prevented by antibiotic treatment; also, it’s rare!

Other Pediatric Signs and Symptoms

Signs and symptoms of pharyngitis break down into 3 groups:

• Febrile response: more common in bacterial infections than non-bacterial infections
• Inflammatory response: tonsillar exudates, anterior cervical lymphadenopathy, severe difficulty swallowing
• Viral symptoms: cough and coryza

The single best predictor of bacterial pharyngitis is tonsillar exudates (both for GAS, and other bacterial pharyngitis). There are also certain signs/symptoms that are more specific to a pediatric population not in the Centor criteria. Scarlatiniform rash is also a high predictor of scarlet fever and palatal petechial is also a high likelihood ratio for strep pharyngitis. The article linked here.

What does a rapid test tell us?

Centor score of 3: A positive test is very useful for knowing that a patient has GAS in their throat (but doesn’t tell us about infection as it could be a carriage state). A negative test in a patient with a high pretest probability is not quite as good.

GAS Treatment

In GAS, a short course of antibiotics is not as good as a long course. Dr Centor recommends 7 days of penicillin, ampicillin or amoxicillin. Cephalosporins are also good. Dr. Berk offers a shot.

What about steroids? The IDSA guidelines suggest no steroids. This Cochrane review shows that dexamethasone can make patients feel better one day faster. Dr. Centor agrees with IDSA here, and his concern is that use of steroids might mask other symptoms.

What are complications of GAS to watch out for?

Peritonsillar abscess: Should be able to tell by a physical exam of the tonsils. If symptoms are getting worse, your patient has difficulty swallowing, continued fever: think of complications of acute pharyngitis, or consider that it could be a different etiology so don’t be afraid to change your differential. 

Retropharyngeal abscess: Seen in children under 5.

Mastoiditis, acute otitis, sinusitis: all fairly rare but important to remember. 

Antibiotic treatment has a NNT close to 200 needed to prevent these suppurative complications.

What about tonsillectomy?

It’s controversial. There are ENT guidelines but the takeaway is that tonsillectomy is not recommended unless there is highly recurrent pharyngitis.

The Adolescent Sore Throat

Bacterial flora changes in adolescents. Group A strep prevalence declines. Group C is a real cause of sporadic tonsillitis and can present with severe tonsillitis and peritonsillar abscess. 

The anaerobe Fusobacterium necrophorum is THE major cause of bacterial pharyngitis. 

Key Takeaway: Suppurative complications peak in the 15-30 age group. That’s where you get the most peritonsillar abscesses and Lemierre’s syndrome. If you only test for Group A strep in this age group, you will miss Group C strep and Fusobacterium.  

What’s up with Fusobacterium?

Fusobacterium is the most common cause of peritonsillar abscess and it can cause Lemierre’s syndrome. If you take care of adolescents, this is what you should be scared of!

The dreaded Lemierre’s Syndrome

Lemierre’s is the extension of bacterial infection into the internal jugular vein causing a suppurative thrombophlebitis. Septic emboli from the IJ can cause severe pulmonary emboli, and fusobacterium is an aggressive bacteria. 

Expert opinion: If a patient in this age group has a 3-4 on a Centor score, but tests negative for GAS, Dr. Centor feels there is a high likelihood this is a different bacterial pharyngitis and recommends antibiotic treatment. This is not the current IDSA recommendation. His first line treatment is with penicillin. [See Annals on Call episode for a fuller discussion]. 

Infectious Mononucleosis

Should always be on your differential in the adolescent/young adult patient. The finding of posterior adenopathy might be suggestive. Can have co-occurring mono and bacterial infection. 

Red Flags for Lemierre’s 

1. Rigors (high likelihood ratio for representative of bacteremia)
2. Unilateral neck swelling (either peritonsillar abscess or Lemierre’s)
3. Pulmonary symptoms
4. No improvement after 5-6 days

Treatment for Lemierre’s

There are not yet guidelines for Lemierre’s: something to look forward to! Most fusobacterium are sensitive to penicillin, often piperacillin – tazobactam. The utility of anticoagulation is unclear. The incidence is 1/70,000 in the 16-30 age group. 

What you shouldn’t forget

In adolescents, if it looks like mononucleosis, and the mono test if negative– you don’t want to miss acute HIV. Don’t forget to take a sexual history! If symptoms last for 1-2 weeks, the differential changes again and includes many other diagnoses including acute leukemia.

A Gonorrhea pearl

Gonorrhea lives in the throat but rarely causes pharyngitis. If gonorrhea is in the throat, it is more likely to cause septicemia, even without pharyngitis. 

Symptom relief for pharyngitis

Throat lozenges, non-steroidals or acetaminophen, and the tincture of time. For some patients with lingering mono, you can give a dose of steroids. 

Takeaways:

• Don’t use the same strategies with adolescents that you use with preadolescents. 
• If your patient is an adolescent and their pharyngitis isn’t improving, ask about red flags for Lemierre’s. 
• Don’t test or treat patients with low Centor or modified Centor scores. 

Links

• Range: How Generalists Triumph in a Specialized World

• First Break All the Rules
• Annals on Call episode: Pharyngitis Debate 

Goal

Listeners will describe the differential diagnosis for acute pharyngitis in the school-aged versus adolescent patient, recall how and why to treat bacterial pharyngitis and to assess for pharyngitis complications in pediatric populations. 

Learning objectives

After listening to this episode listeners will…  

• Define acute pharyngitis
• Describe the differential diagnosis for acute pharyngitis in the school-aged versus adolescent patient
• Be familiar with the utility of the Modified Centor criteria
• Describe the utility of antibiotic and adjunctive medications for acute pharyngitis
• Learn about common and rare complications of bacterial pharyngitis

Disclosures

Dr. Centor reports no relevant financial disclosures. The Cribsiders report no relevant financial disclosures.

Citation

Centor R, Raymond-Kolker R. Chiu C, Berk J. “Pediatric Pharyngitis”. The Cribsiders Pediatric Podcast. https:/www.thecribsiders.com/ 8/19/20.