PHARYNGITIS: Management Considerations

PEARLS for the MANAGEMENT of PHARYNGITIS  The majority of pharyngitis cases do NOT require antibiotics as they are viral infections (80-90% in adults, >70% in children).  Pharyngitis is typically self-limiting (often 3-7 days; up to 10 days).  A validated clinical decision rule e.g. modified Centor score can help identify low risk patients who do not require diagnostic testing (see below) or antibiotics.  For confirmed Group A Streptococcus (GAS) pharyngitis, penicillin for 10 days is the drug of choice. There is no documented GAS resistance to penicillin.  Advise on treatments that will provide symptomatic relief: NSAIDs, acetaminophen, medicated throat lozenges, topical anesthetics, warm liquids.  Patients should see their prescriber if: 1) symptoms worsen, 2) symptoms take longer than 3 to 5 days to resolve, &/or 3) unilateral neck swelling develops.

 Diagnostic testing is not recommended if: -A modified Centor score of ≤1 symptoms of a viral infection rhinorrhea, cough, oral ulcers, hoarseness IDSA 2012 (strong, high) -<3yrs, unless other risk factors e.g. sibling with GAS infection IDSA 2012 (strong, moderate) asymptomatic contact of patient with GAS pharyngitis IDSA 2012 (strong, moderate)  Exceptions: the modified Centor score may not accurately predict risk of GAS during epidemics or in high risk populations, e.g. individuals with a history of rheumatic fever, valvular heart disease, or immunosuppression. Use clinical judgment & consider testing (RADT/throat swab) more broadly.

SHOULD ANTIBIOTICS BE USED TO TREAT PHARYNGITIS?
 80-90% of adults (>70% of children) do NOT require antibiotics as infection likely viral.  Patients with a positive throat swab should receive an antibiotic to  the risk of complications. See modified Centor score on left column, & antibiotic table below.  The turn-around-time for throat swab results can take a few days. However, antibiotics started within 9 days of symptom onset in confirmed GAS will prevent rheumatic fever.  If antibiotics are started empirically, ensure agent is discontinued if throat swab negative.

MOST COMMON BACTERIAL PATHOGEN
 Group A Streptococcus (GAS) (

PENICILLIN ALLERGY: TYPE I HYPERSENSITIVITY (i.e. anaphylaxis)
Do not use the following antibiotics unless confirmed GAS & confirmed type I reaction to penicillin, due to concerns with ↑ resistance to macrolides & adverse events e.g. C. diff.

Macrolide considerations:
-Clarithromycin x 10 days was superior to azithromycin x 5 days for bacterial eradication (NNT=9) in adults, but equivalent for clinical cure. -↑ GI side effects with erythromycin.
-Azithromycin 3 vs 5 days: no head-to-head trials. Both regimens provide same total dose over the course of therapy (i.e. 60mg/kg/d; 1.5g).

MEDICATED SPRAYS
Phenol CHLORASEPTIC 5 sprays q2hr PRN -No evidence, but anecdotally may provide relief from associated pain.
Not recommended for symptom management: corticosteroids NICE'18, IDSA'12 (weak, moderate) ; however, opinions vary (e.g., may consider dexamethasone 10mg po x 1 dose). BMJ'17 (weak)  A systematic review of 10 RCTs (1426 participants) found a single, low-dose (usually dexamethasone max 10mg) vs standard care ↑ pain relief at 24h & the number of patients' experiencing no pain at 48h (NNT=6, high quality). Pain resolved ~11h (-0.4 to -21.8, low quality) earlier with corticosteroid treatment, but wide variability. AEs were not different, but multiple corticosteroid doses were not studied & would likely lead to greater harms e.g., ↑glucose. Sadeghirad'17  Some may consider in duration of pain is not considered clinically significant, and NSAIDs/acetaminophen have less adverse events. Shared decision-making is required.

Treatment Evidence Summary
Penicillin vs Cephalosporins vs Macrolides: penicillin remains the antibiotic of choice  There is no clinically relevant difference in symptom resolution between antibiotics.  Penicillin has the most evidence for preventing complications; has a narrow spectrum; is efficacious, safe, inexpensive; & there is no documented resistance to GAS.

Clinical Q&A
What is the risk of acute rheumatic fever?  In Canada, the current prevalence of acute rheumatic fever is 0.1 to 2 cases per 100,000.
-The incidence in some remote, Canadian Aboriginal communities may be higher (i.e. Northern Ontario 8.33/100,000). -The risk may also be higher in immigrants from endemic areas, e.g. Philippines, China.  It is difficult to estimate the risk of acute rheumatic fever due to untreated pharyngitis: -as the majority of studies comparing antibiotics versus placebo were conducted prior to the 1960s (higher rate of acute rheumatic fever, and in young males from the US Armed Forces) -bacterial versus viral etiology was often not confirmed -newer studies have either no documented cases or did not assess this outcome  In an effort to balance unnecessary antibiotic use with preventing rheumatic fever: -use the modified Centor score to identify patients who require a throat swab/RADT -wait to prescribe antibiotics until the results of the throat swab are available  starting antibiotics within 9 days of symptom onset prevents acute rheumatic fever  if antibiotics are started empirically, discontinue if throat swab is negative  children are at a greater risk of complications (e.g. otitis media, peritonsillar abscess, rheumatic fever); may initiate antibiotics sooner  A full 10 day course of penicillin is recommended for confirmed GAS pharyngitis.

Pharyngitis caused by Chlamydia trachomatis
 It is rare that Chlamydia trachomatis causes pharyngifis, but rates appear to be ↑.  Risk factors include: age 15 -24 years, sexually active, engagement in oral sex.  In Saskatchewan, Chlamydia trachomatis screening requires a different lab requisition.  Treatment: doxycycline 100mg po BID x 7days, or azithromycin 1g x 1 dose.

Management of Recurrent Pharyngitis
 Potential causes: recurrent pharyngitis due to inadequate eradication, new infection, viral infection in an asymptomatic carrier ~20% of the population are GAS carriers.  Controversial as to whether or not asymptomatic carriers with recurrent pharyngitis need to be identified.  Identification may help avoid antibiotics in those with recurrent viral pharyngitis.  Avoid identifying asymptomatic carriers without recurrent pharyngitis.  Consider age, season, signs/symptoms to rule out viral etiology (see modified Centor score).  Avoid continuous long-term antibiotic therapy (i.e. repeated courses or prophylaxis).
Abbreviations: =tastes good GAS=Group A Streptococcus GI=gastrointestinal IDSA=Infectious Diseases Society of America NSAID=non-steroidal anti-inflammatory drug NNT=number needed to treat OR=odds ratio PRN=as needed RADT=rapid antigen detecting test RCT=randomized controlled trial RR=relative risk