Pharyngitis With Dr. Centor From The Cribsiders With Additional Resources

In this post I link to and excerpt from the Cribsiders‘ Aug 19, 2020 podcast and show notes by Dr Justin Berk, More Than Strep: Pharyngitis w/ “Uncle Bob” Centor [with additional resources from Tiny Tips: Modified Centor Score for Streptococcal Pharyngitis, Jan 18, 2017, Canadiem]:

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.

Here is the outstanding podcast:

Here are excerpts from the show notes:

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.

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

*Lemierre’s Syndrome: Oropharyngeal infection leading to secondary septic thrombophlebitis of the internal jugular vein; Necrobacillosis

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.

* Modified Centor Score For Streptococcal Pharyngitis from Jan 18, 2017 from Canadiem.

Table below is from Canadiem post

For patients presenting with:

1. Sore Throat
2. URTI Symptoms

Symptoms or Signs	Points
1.     History of Fever or measured temperature >38oC	+1
2.     Absence of Cough	+1
3.     Tender/Swollen anterior cervical lymphadenopathy	+1
4.     Tonsillar swelling or exudate	+1
Age < 3-14 years*	+1
Age 15 – 44 years	0
Age ≥ 45 years	-1

The following is also from the Canadiem post:

Upper Respiratory Infection symptoms like cough or sore throat are still some of the top reasons for Canadian emergency department visits, and will likely be even higher in the upcoming months and in Urgent Care Centres.1 The most common organisms responsible for uncomplicated acute pharyngitis are viral agents at 50-80% and Streptococcal agents, specifically Group A Beta-Hemolytic Strep, at 5-36%.2 It is clinically significant to differentiate between these two pathogens as patients with the latter would benefit from antibiotic therapy, and patients with the former should not have antibiotic therapy due to deriving no benefit.

Here is the mneumonic for the modified Centor decision rule (aka McIsaac Score) and the recommendations for treatment based on the Modified Centor Score from the Canadiem post:

The mnemonic for the Modified Centor decision rule (a.k.a. the McIssac Score) is relatively straight forward: M-CENTOR!

Must be older than 3 years old
Cough — No Cough (+1)
Exudates or Swelling — Tonsillar exudates/swelling (+1)
Nodes — Anterior Cervical adenopathy (+1)
Temperature — Hx of fever or Temperature >38 (+1)
Only Young — patients <15yo (+1)*
Rarely Elder — Patients >45 (-1)

Interpretation of Modified Centor Score
Total Points	Risk Level	Percentage of patients with Strep Pharyngitis (based on cultures)	Suggested Management
< 1	Low risk	1-10%	No culture or antibiotics necessary, return if worse
2 – 3	Moderate risk	10-28%	Culture all, treat if culture result positive
> 4	High risk	38-63%	Culture all, treat empirically with antibiotics

The following is also from the Canadiem post:

Recommendations in the original McIssac paper and by the American Association of Family Practice (AAFP) in 2009 were that low risk patients can be discharged home with no further testing or antibiotics indicated.⁷–⁸ Moderate risk patients can be offered throat culture or rapid antigen detection test (RADT) and treated if culture/RADT was positive, and high risk patients with scores >4 were to be empirically treated with 10 day course of oral antibiotics – Penicillin VK for us Canadians.⁸ Erythromycin is commonly patients with a penicillin allergy.⁸

More recently, the Infectious Disease Society of America (IDSA) 2012 pharyngitis guidelines recommended against empiric antibiotic therapy for acute uncomplicated pharyngitis and to instead offer RADT/throat culture to all moderate and high risk patients and treat them based on results of the tests due to the increase availability and accuracy of RADT as well as low incidence of streptococcal pharyngitis complications such as peritonsillar abscess and rheumatic fever⁹.

This approach would present additional challenges to the Emergency Medicine setting, where low-acuity patients are rarely followed by the ED physician following discharge. Some potential practice patterns include having throat culture results faxed to the ED to be followed up by another colleague, having the patient’s family physician follow up on the throat culture results, and ED physician follow up on the throat culture results on his/her own time. There are advantages and drawbacks to each of these solutions, and would likely depend on ED physician and group preferences/practices.

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

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.

*Differences Among International Pharyngitis Guidelines: Not Just Academic [PubMed Central] [Full Text HTML] [Full Text PDF]. Ann Fam Med. Sep-Oct 2007;5(5):436-43.

The above article has been cited by 42 articles in PubMed Central.