Overview
Definition:
Pharyngitis refers to inflammation of the pharynx, commonly presenting as a sore throat
In children, the most significant concern is Group A Streptococcus (GAS) pharyngitis, which can lead to acute rheumatic fever and post-streptococcal glomerulonephritis if untreated
Viral causes are far more common.
Epidemiology:
Pharyngitis is a frequent reason for pediatric visits
GAS pharyngitis incidence peaks in school-aged children (5-15 years), with lower rates in preschoolers and adults
Outbreaks can occur in congregate settings like schools and daycares.
Clinical Significance:
Accurate diagnosis and timely treatment of GAS pharyngitis are crucial to prevent serious suppurative and non-suppurative complications
Differentiating GAS from viral etiologies guides appropriate antibiotic use, mitigating antibiotic resistance and unnecessary treatment.
Clinical Presentation
Symptoms:
Sudden onset sore throat
Odynophagia (painful swallowing)
Fever, often >38.3°C
Headache
Abdominal pain, nausea, or vomiting, particularly in younger children
Absence of cough or rhinorrhea strongly suggests GAS
Petechiae on the palate may be present
Tonsillar exudates, erythema, and swelling are common
Palatal petechiae may be present
Scarlet fever rash (fine, erythematous, sandpaper-like) can occur with GAS infection.
Signs:
Erythematous pharynx and tonsils
Tonsillar exudates (white or yellow patches)
Enlarged and tender anterior cervical lymph nodes
Scarlatiniform rash (if present)
Uvular edema
High fever.
Diagnostic Criteria:
The CENTOR score (modified by McIsaac) helps stratify the likelihood of GAS pharyngitis in symptomatic children and adults
Each criterion present adds one point: 1
Tonsillar exudates
2
Swollen, tender anterior cervical lymphadenopathy
3
History of fever (oral temperature >38°C or 100.4°F)
4
Absence of cough
5
Age 3-14 years (McIsaac modification)
A score of 0-1 suggests low probability of GAS, 2-3 intermediate, and 4-5 high probability.
Diagnostic Approach
History Taking:
Detailed history of symptom onset, duration, and severity
Presence/absence of cough, rhinorrhea, conjunctivitis, diarrhea, or other viral symptoms
Exposure to strep throat or scarlet fever
History of rheumatic fever
Vaccination status
Recent antibiotic use.
Physical Examination:
Thorough examination of the oropharynx, noting erythema, exudates, petechiae, and uvular edema
Palpation of cervical lymph nodes for enlargement and tenderness
Examination for rash (scarlatiniform)
Auscultation of lungs to rule out pneumonia.
Investigations:
Rapid antigen detection test (RADT) for GAS: High specificity, variable sensitivity
If RADT is positive, empirical treatment for GAS is recommended
If RADT is negative and suspicion for GAS is moderate to high (CENTOR/McIsaac score ≥2), a throat culture should be performed
Throat culture: Gold standard for GAS diagnosis, high sensitivity and specificity
PCR tests are also available with high sensitivity and specificity.
Differential Diagnosis:
Viral pharyngitis (most common, often associated with cough, rhinorrhea, conjunctivitis, oral ulcers): Adenovirus, enterovirus, rhinovirus, influenza, parainfluenza, Epstein-Barr virus (infectious mononucleosis - consider in adolescents with prolonged fever, lymphadenopathy, splenomegaly)
Other bacterial causes: Mycoplasma pneumoniae, Chlamydia pneumoniae, Arcanobacterium haemolyticum (can cause rash)
Non-infectious causes: Allergies, irritants, gastroesophageal reflux disease, Kawasaki disease (if fever >5 days, conjunctivitis, rash, extremity changes, cervical lymphadenopathy).
Management
Initial Management:
Based on clinical suspicion and diagnostic testing
For confirmed or highly suspected GAS pharyngitis, antibiotic therapy is indicated
Symptomatic relief for all types of pharyngitis.
Medical Management:
For confirmed GAS pharyngitis: First-line: Amoxicillin 50 mg/kg/day divided into two doses (max 1000 mg/day) for 10 days
Penicillin V 25-50 mg/kg/day divided into two or three doses (max 1000 mg/day) for 10 days
Alternatives for penicillin allergy: Azithromycin 10 mg/kg on day 1, then 5 mg/kg/day for 4 days
or Clarithromycin 7.5 mg/kg/dose twice daily for 10 days
Symptomatic relief: Antipyretics (acetaminophen 10-15 mg/kg/dose q4-6h or ibuprofen 5-10 mg/kg/dose q6-8h), cool fluids, throat lozenges/sprays, saline gargles.
Surgical Management:
Rarely indicated for pharyngitis itself
Indications may include peritonsillar abscess or severe airway compromise, which are complications.
Supportive Care:
Encourage fluid intake
Rest
Monitor for signs of complications
Ensure adherence to antibiotic therapy
Education on preventing spread (hand hygiene, not sharing utensils).
Complications
Early Complications:
Peritonsillar abscess (quinsy)
Retropharyngeal abscess
Cervical lymphadenitis
Scarlet fever
Pneumonia
Otitis media
Sinusitis
Bacteremia.
Late Complications:
Acute rheumatic fever (ARF) – risk significantly reduced by prompt antibiotic treatment
Post-streptococcal glomerulonephritis (PSGN) – less clearly prevented by antibiotics, but early diagnosis and treatment of GAS infection may reduce overall incidence
Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) – controversial association, characterized by sudden onset of obsessive-compulsive symptoms.
Prevention Strategies:
Prompt diagnosis and treatment of GAS pharyngitis with appropriate antibiotics is the primary strategy to prevent ARF
Good hand hygiene, covering coughs/sneezes, and avoiding close contact with infected individuals can limit transmission
Educating families on recognition of symptoms and seeking medical attention.
Prognosis
Factors Affecting Prognosis:
Timeliness and adherence to antibiotic treatment significantly impact the risk of complications, particularly ARF
Prompt treatment of GAS pharyngitis leads to rapid symptomatic relief and prevents sequelae
Untreated GAS pharyngitis carries a risk of ARF and PSGN.
Outcomes:
With appropriate antibiotic therapy, most children recover fully from GAS pharyngitis within 24-72 hours, with resolution of symptoms and no long-term sequelae
Recurrence is possible if initial treatment is inadequate or if re-exposure occurs.
Follow Up:
Clinical follow-up is generally not required if symptoms resolve with treatment and complications are absent
However, in areas with high incidence of ARF or in children with a history of ARF, closer follow-up and possibly secondary prophylaxis against GAS are crucial
Educate parents on recognizing recurrence or signs of complications.
Key Points
Exam Focus:
CENTOR/McIsaac criteria for GAS probability
Indications for rapid strep testing and throat culture
Antibiotic of choice and duration for GAS pharyngitis
Complications of untreated GAS (ARF, PSGN)
Management of viral pharyngitis.
Clinical Pearls:
Always consider GAS in children with sore throat, especially those lacking cough/rhinorrhea
A negative RADT in a child with high suspicion (score ≥2) warrants a throat culture
Complete the full 10-day antibiotic course for GAS to ensure eradication and prevent ARF
Amoxicillin is the preferred agent for GAS pharyngitis due to palatability and efficacy.
Common Mistakes:
Over-reliance on RADT sensitivity without confirmatory throat culture when suspicion is high
Inappropriate antibiotic use for viral pharyngitis, contributing to resistance
Incomplete antibiotic courses for GAS
Failure to consider complications like peritonsillar abscess or ARF.