Acute Pharyngitis -
Definition and Etiologies
Acute pharyngitis refers to inflammation of the pharynx, caused by viruses (most common),
bacteria, and non-infectious factors (e.g., allergies, pollutants).
It includes erythema, edema, exudates, or an enanthem (ulcers, vesicles).
It can be involved in various inflammatory conditions such as periodic fever, adenitis
(PFAPA) syndrome, Kawasaki disease, MIS-C, IBD, SLE.
Most prevalent bacterial cause: Group A Streptococcus (GAS).
Infectious Etiologies
Viruses: Influenza, RSV, adenovirus, Epstein-Barr Virus (EBV), herpes simplex virus (HSV),
and COVID-19.
Bacteria: GAS, Fusobacterium necrophorum (linked to Lemierre syndrome), Neisseria
gonorrhoeae, and Corynebacterium diphtheriae.
In Industrialized countries, GAS is the most important bacterial cause of acute pharyngitis.
However, viruses predominate as acute infectious causes of pharyngitis.
Key Clinical Features
GAS Pharyngitis: Sudden sore throat onset, fever, headache, abdominal pain, tonsillar
exudates, tender anterior cervical adenopathy, absence of cough/coryza.
More common in 5-15 years old. Can result in either asymptomatic carriage or acute
infection. After an incubation period of 2-5 days, it presents with sore throat and fever,
pharynx is red, tonsils are enlarged, covered with a white, grayish or yellow exudate.
Headache, abdominal pain and vomiting
Viral Pharyngitis: Conjunctivitis, cough, diarrhea, hoarseness, and rhinorrhea.
Primary oral HSV infection: gingivostomatitis and ulcerating vesicles throughout the
anterior pharynx, on the lips and perioral skin. Patient presents with high fever and
difficulty taking oral fluids that last for 14 days.
Herpangina caused by enteroviruses, presents as papulovesicular lesions or ulcerations in
the posterior oropharynx, severe throat pain and fever
Hand-foot-mouth disease, caused by coxsackie A16, presents as vesicles or ulcers
throughout the oropharynx, on the palms and soles, and sometimes on the trunk and
extremities
Intense diffuse pharyngeal erythema and Koplik spots, occurs in measles, splenomegaly,
lymphadenopathy or hepatomegaly that could give the clue to EBV infectious
mononucleosis in an adolescent with exudative tonsilitis
Primary infection with HIV can manifest as acute retroviral syndrome with nonexudative
pharyngitis, fever, arthralgia, myalgia, adenopathy and maculopapular rash
Diagnostic Tools
Laboratory testing is essential for an accurate diagnosis. Clinical findings and/or scoring
systems can be used to assist for further testing.
McIsaac Score: Helps predict GAS likelihood based on symptoms (e.g., fever, age, anterior
cervical adenopathy).
McIsaac give one point for each of the following criteria: history of temperature more than
38C, absence of cough, tender anterior cervical adenopathy, tonsillar swelling or exudates
and age 3-14 years. It subtracts a point for age equal or more than 45 years.
If score is equal or more than 4, associated with a positive laboratory test for GAS.
Throat culture, rapid antigen-detection tests or PCR tests are diagnostics for GAS; RADT
(Rapid Antigen Detection Tests) and throat culture: Standards for diagnosing GAS.
Treatment Guidelines
First-line antibiotics for GAS: Amoxicillin, penicillin V (10 days), Penicillin G (single IM
dose).
Penicillin-allergic patients: Cephalosporins, erythromycin, or clindamycin.
Viral pharyngitis: Symptomatic treatment only (e.g., analgesics, antipyretics).
Complications
GAS: Acute rheumatic fever (ARF), peritonsillar abscess, post-streptococcal
glomerulonephritis.
F. necrophorum: Lemierre syndrome.
Chronic Carriers
Up to 5% of the population may be GAS carriers, often asymptomatic but with potential for
recurrent infections.
1. Which of the following is the most common viral cause of acute pharyngitis in
children?
A) Adenovirus
B) Epstein-Barr virus (EBV)
C) Rhinovirus
D) Group A Streptococcus
2. Which clinical feature is most suggestive of group A streptococcal (GAS)
pharyngitis in a child?
A) Cough, runny nose, and hoarseness
B) Sudden onset of sore throat, fever, and exudative tonsillitis
C) Mucopurulent nasal discharge and conjunctivitis
D) Rash with a "slapped cheek" appearance
3. Which of the following is the preferred diagnostic test for confirming group A
streptococcal pharyngitis?
A) Throat culture
B) Rapid antigen detection test (RADT)
C) Complete blood count (CBC)
D) Monospot test
4. Which of the following is a common complication of untreated group A
streptococcal pharyngitis?
A) Rheumatic fever
B) Laryngotracheobronchitis
C) Acute otitis media
D) Peritonsillar abscess
5. Which of the following is the recommended first-line antibiotic treatment for
a child diagnosed with group A streptococcal pharyngitis?
A) Azithromycin
B) Amoxicillin
C) Ciprofloxacin
D) Clindamycin
6. A child presents with a sore throat, fever, and a sandpaper-like rash. The
diagnosis of scarlet fever is suspected. Which organism is most commonly
responsible for this condition?
A) Epstein-Barr virus
B) Streptococcus pneumoniae
C) Group A Streptococcus
D) Mycoplasma pneumoniae
7. Which of the following clinical signs would be concerning for a potential
complication of pharyngitis, such as a peritonsillar abscess?
A) Difficulty swallowing, neck swelling, and trismus
B) Cough and rhinorrhea
C) Red eyes and conjunctivitis
D) Fine maculopapular rash
8. Which of the following is the most likely cause of acute pharyngitis in a child
with a history of recent mononucleosis?
A) Epstein-Barr virus (EBV)
B) Parainfluenza virus
C) Streptococcus pyogenes
D) Adenovirus
9. Which of the following statements about the management of acute pharyngitis
in children is correct?
A) Antibiotics should be prescribed to all children with sore throat.
B) Group A streptococcal pharyngitis should always be treated with a 10-day course of
antibiotics.
C) Only symptomatic treatment is recommended for children with viral pharyngitis.
D) Antipyretics are contraindicated in viral pharyngitis.
10. Which of the following is the most appropriate next step in the management of
a child with a sore throat and a negative rapid antigen test but high clinical
suspicion for group A streptococcus?
A) Prescribe antibiotics immediately.
B) Perform a throat culture.
C) Monitor symptoms and consider antibiotics if they worsen.
D) No treatment is necessary.
Answers:
1- Answer: A) Adenovirus
2- Answer: B) Sudden onset of sore throat, fever, and exudative tonsillitis
3- Answer: B) Rapid antigen detection test (RADT)
4- Answer: A) Rheumatic fever
5- Answer: B) Amoxicillin
6- Answer: C) Group A Streptococcus
7- Answer: A) Difficulty swallowing, neck swelling, and trismus
8- Answer: A) Epstein-Barr virus (EBV)
9- Answer: C) Only symptomatic treatment is recommended for children with
viral pharyngitis.
10- Answer: B) Perform a throat culture.
