If It's Not in the Differential, It Won’t be in the Diagnosis: Pharyngitis

If It’s Not in the Differential, It Won’t Be in the Diagnosis: Pharyngitis

Gita Pensa, MD, and Mike Weinstock, MD

1. Streptococcal Pharyngitis

CENTOR Criteria: A listing of 4 criteria that can be used to estimate the probability that pharyngitis is streptococcal and to suggest a potential management course.  

1. • Cough (absent) 
   • Adenopathy 
   • Fever, 
   • Exudate (tonsillar)

• The more CENTOR criteria present, the higher the probability of Strep pharyngitis, but how accurate is this? Estimates suggest that 
• • 1 out of 4 has a 10% probability of Strep pharyngitis, 
  • 2 out of 4 has a 20% probability, 
  • 3 out of 4 has a 35% probability, and 
  • 4 out of 4 has a 50% probability

It is suggested that for a score of 2 or less, no further treatment is recommended; for a score of 3 or 4, you can pursue a rapid Strep antigen detection test (RADT) to determine treatment based on your “clinical gestalt.”

Modified CENTOR criteria:

1. 1. Fever
   2. Lymphadenopathy (LAN)
   3. Exudate
   4. No cough +
   5. Age:
      1. Age 3-14 (plus 1 point)
      2. Age 15-44 (0)
      3. Age over 45 (minus 1 point)

2. Mononucleosis
   • Post-cervical LAN
   • Fatigue
   • Splenomegaly
3. Peritonsillar abscess
   • Uvular deviation
   • Peritonsillar enlargement
   • Etc
4. Retropharyngeal abscess
   • Surgical emergency
   • Odynophagia
   • Fever
   • ? Preceding pharyngitis?
5. Diphtheria

• • Pharyngitis
  • Fever
  • Cervical lymphadenopathy
  • Gray membrane in posterior pharynx which is friable
  • Suspect in patients who live in endemic areas and unvaccinated patients

6. Epiglottitis
   • Disease of adults (used to be children before HIB vaccine)
   • Classic sitting forward drooling – now presents more gradually
7. Herpes simplex virus
   • Vesicles or ulcerations on exam
   • May not see if not able to adequately visualize the post pharynx
8. Airway obstruction from any cause
   • Foreign body
   • Mass
9. Cancer of the head and neck
   • Weight loss
   • Smoker
   • Patient with 3 rounds of antibiotics
10. Allergic rhinitis
11. Gastroesophageal reflux disease
    • Irritation from recurrent acidic reflux
    • Worse after intake of acid type foods
12.  Lemierre’s syndrome - thrombophlebitis of the internal jugular vein
    • Lateral neck pain
    • Treatment is ATB and anticoagulation
13. Sexually transmitted infections
    • Gonorrhea - can occur as high as 15% of the time in men who have sex with men (MSM) - may be asymptomatic
    • Chlamydia
    • Syphilis 

• Warning signs
• Drooling
• Respiratory distress
• Trismus
• Muffled voice
• Neck symptoms (vascular, infectious, thrombosis)
• Respiratory distress (tachypnea, dyspnea, retractions)
• Sniffing or tripod positions
• Sepsis physiology

Other warning signs to look for: 

• Severe unilateral sore throat
• Bulging of pharyngeal wall, soft palate, or floor of the oropharynx
• Neck pain or swelling
• Crepitus
• Trismus (irritation and reflex spasm of the internal pterygoid muscle)
• Stiff neck
• Toxic appearance
• Fever and rigors
• History of penetrating trauma to the oropharynx

REFERENCES:

Pharyngitis (Strep Throat). https://www.cdc.gov/groupastrep/diseases-hcp/strep-throat.html

Pharyngitis: approach to diagnosis and treatment
Sykes EA, Wu V, Beyea MM, Simpson MTW, Beyea JA. Can Fam Physician. 2020;66(4):251-257.

Clinical practice guideline for the diagnosis and management of group A streptococcal pharyngitis: 2012 update by the Infectious Diseases Society of America
Shulman ST, Bisno AL, Clegg HW, et al. Clin Infect Dis. 2012;55(10):e86-e102. doi: 10.1093/cid/cis629.  [Published correction appears in Clin Infect Dis. 2014 May;58(10):1496. Dosage error in article text]