Pharyngitis / Sore Throat

• One of four most common episodic clinic visit reasons
• Key points
  • Most children with sore throats do not need antibiotics
  • With the exception of scarlet-fever type rash, there are no clinical features alone that reliably discriminate between Group A streptococcal (GAS) and viral pharyngitis
  • Antibiotic therapy is ONLY recommended for a high-risk group of children to prevent non-suppurative complications of GAS infection
• Background
  • Most commonly affects ages 5 to 12 years old
  • Not usually seen in children under age 3
  • The most common cause of sore throat in children is a viral illness and are self-limiting and symptoms usually resolve within 7 days.
  • Bacterial infection is a less common cause of sore throat
    • Streptococcus pyogenes (group A streptococcus) is the most frequently implicated bacterial pathogen and is more common in children than in adults.
    • Group A streptococcal (GAS) pharyngitis is rare under four years of age

• Anatomy:
  • Waldeyer’s Tonsillar ring – ring of lypmhoid tissue formed by
    • Nasopharynx: Adenoids (pharyngeal Tonsils) at posterior wall
    • Tubal tonsils
    • Oropharynx: Faucial (Palatine Tonsils) at lateral wall)
    • Hypopharynx: Lingual Tonsil at Tongue base

causes
Condition	Details
conditions associated with airway obstruction or deep neck space infection	Acute epiglottitis Peritonsillar abscess (quinsy) Retropharyngeal abscess Parapharyngeal abscess pharyngeal diphtheria Epstein–Barr virus (EBV) infection – severe Croup – severe Bacterial Tracheitis – severe Spreading odontogenic infections (including Ludwig angina) Septic jugular thrombophlebitis (part of Lemierre syndrome)
viral pharyngitis and tonsillitis	Most common cause of sore throat in patients of all ages. Common respiratory viruses include – respiratory syncytial virus – rhinovirus – adenovirus – influenza virus – parainfluenza virus Other: COVID-19, SARS-CoV-2 Clinical features include: – cough – hoarse voice – conjunctivitis – nasal congestion – anterior stomatitis -viral exanthema – diarrhoea
Streptococcus pyogenes (GAS) pharyngitis and tonsillitis	– common in school-aged children and adolescents Clinical features include: – abrupt onset of symptoms – fever (above 38°C) – tender cervical lymphadenopathy – tonsillar exudate – classic rash of scarlet fever – absence of cough, rhinorrhoea or nasal congestion.
Epstein–Barr virus (EBV) infection (glandular fever, infectious mononucleosis)	– common in adolescents and young adults. Clinical features include: – severe sore throat – fever – nausea – lymphadenopathy – splenomegaly – hepatomegaly – rash and fatigue If suspected, consider performing an infectious mononucleosis (IM) test or EBV serology.
primary oral mucocutaneous herpes (herpes gingivostomatitis)	– common in children younger than 5 years Clinical features include – fever – intraoral or hypopharyngeal lesions – aphthous tonsil ulcers – cervical lymphadenopathy. If suspected, consider collecting a throat swab for HSV-PCR
hand, foot and mouth disease	– common in children.Usually caused by coxsackieviruses. Clinical features include – vesicular or ulcerative mucosal eruptions in the mouth and throat – loss of appetite – rash or skin lesions
Herpangina	– common in children – caused by coxsackieviruses Clinical features include: – high fever (above 38.5°C) – vesicular or ulcerative mucosal eruptions in the mouth and throat – cervical lymphadenopathy – headache – abdominal pain – vomiting – loss of appetite
STD: Neisseria gonorrhoeae infection Early syphilis	– in sexually active patients – usually asymptomatic, but patients can present with pharyngeal symptoms.
Arcanobacterium haemolyticum (formerly Corynebacterium haemolyticum) pharyngitis and tonsillitis	– uncommon cause of pharyngitis and tonsillitis – more common in patients aged 10 to 24 years. Clinical features : – similar to streptococcal pharyngitis and tonsillitis – Consider diagnosis in patients who do not respond to empirical antibiotic therapy for streptococcal infection. – A rash, similar to scarlet fever, may occur and can be misattributed to penicillin hypersensitivity – Can be identified on throat swab culture; request laboratory to specifically look for this organism to increase the yield.
rarer bacterial causes	– Group C and G streptococci (management is generally the same as for S. pyogenes pharyngitis and tonsillitis – Corynebacterium diphtheriae – mixed infections with anaerobic bacteria Mycoplasma pneumoniae Chlamydophila pneumoniae Fusobacterium necrophorum (10% of young adults and adolescents, Risk of Lemieres Syndrome)
non-infective causes	Trauma GORD postnasal drip due to allergic rhinitis and rhinosinusitis house dust mite allergy cigarette smoke dry air snoring tracheal intubation malignancy medications.

Herpangina	Herpangina
herpes gingivostomatitis	herpes gingivostomatitis

Symptoms

• Sore Throat
  • Dysphagia (Difficulty Swallowing)
  • Odynophagia (pain with Swallowing)
• Symptoms suggestive of viral illness
  • cough
  • hoarse voice
  • nasal congestion
  • anterior stomatitis
  • viral exanthema
  • diarrhoea
  • Diffuse myalgias (seen in Influenza)
  • Conjunctivitis (esp. Adenovirus)
  • Diffuse Lymphadenopathy in Cytomegalovirus (CMV), Mononucleosis (EBV), Acute HIV Infection)
• Symptoms suggestive of Bacterial illness (Group A Streptococcal Pharyngitis)
  • abrupt onset of symptoms
  • fever (above 38°C)
  • tender cervical lymphadenopathy
  • tonsillar exudate
  • absence of cough, rhinorrhoea or nasal congestion
  • S. pyogenes can be associated with scarlet fever
    • children between the ages of 5 and 15 years
    • sudden high fever (above 38.5°C)
    • followed by a distinctive rash (red initially, becoming dry and rough with a sandpaper feel)
    • facial flushing with circumoral pallor
    • tongue discolouration (white initially, becoming red and bumpy [strawberry tongue])

Red flags (suggestive of serious cause)

1. Unilateral Pharyngitis
2. Toxic appearance
3. Associated neck swelling
4. Drooling (airway compromise)
5. Stridor (airway compromise)
6. Respiratory distress
7. Trismus
8. “Hot potato” voice (muffled voice associated with pharyngeal/peritonsillar pathology)
9. Torticollis
10. Neck stiffness/fullness

Examine with caution if the child has clinical signs of Acute upper airway obstruction

Assess

• Hydration status
• Fever  
• Oral/pharyngeal ulcers (coxsackie virus)      
• Tonsillar exudates                              
• Tender anterior cervical lymphadenopathy
• Hepatosplenomegaly (EBV)
• Scarlet-fever type rash – blanching, sandpaper-like rash, usually more prominent in skin creases, flushed face/cheeks with peri-oral pallor (GAS)

• Signs
  • Viral
    • Non-exudative pharyngeal erythema
      • Exception: Tonsillar exudate in Mononucleosis (EBV)
    • Vesicular OR ulcerative Oral Lesions
    • Conjunctivitis in Adenovirus and Kawasaki Disease
  • Streptococcus and other Bacteria
    • Enlarged Tonsils with or without exudate
    • Petechiae on Soft Palate (pathognomonic)
    • Erythema
    • Tender Cervical Lymphadenopathy
    • Strawberry Tongue (in Scarlet Fever)
  • Peritonsillar Cellulitis or Peritonsillar Abscess
    • Unilateral erythema of Soft Palate
    • Uvula deviated
    • Dysphagia
    • Odynophagia
    • Fever
  • Diphtheria
    • Gray membranous exudate covers Tonsils and pharynx
    • Exudate bleeds easily on removal
  • Kawasaki Disease
    • Conjunctivitis (also in Adenovirus)
    • Palmar erythema and cracked red lips after 3 days
    • Non-purulent

Management

Symptomatic therapy includes:

• mild moderate
  • paracetamol
  • NSAIDs
  • medicated lozenges containing an antiseptic, anti-inflammatory or anaesthetic drug, or medicated throat sprays containing an anti-inflammatory drug, to relieve throat pain in adults and adolescents.
• severe symptoms of sore throat (eg severe throat pain, dysphagia, drooling)
  • dexamethasone 10 mg (child: 0.15 to 0.6 mg/kg up to 10 mg) orally, as a single dose OR
  • prednisolone 50 mg (child: 1 mg/kg up to 50 mg) orally, daily for 1 or 2 days OR
  • prednisone 50 mg (child: 1 mg/kg up to 50 mg) orally, daily for 1 or 2 days

Strep Throat

• Epidemiology
  • Most commonly affects ages 5 to 12 years old
  • Not usually seen in children under age 3
  • Incubation: 24 to 72 hours
  • Transmission: direct person to person contact
    • Passed by Saliva and nasal secretions
    • Increased in crowded settings
    • May be transmitted with food preparation
    • Transmission rate from Streptococcus carriers is 3-11%
  • Infectivity
    • Decreases 1-3 days after antibiotic started
    • Return to School and day care recommendations
      • Antibiotics for minimum of 24 hours
      • No fever
• Etiology
  • Streptococcus Pyogenes (Group A Beta-hemolytic Streptococcus)
• Complications
  • Non-suppurative
    • Rheumatic Fever
    • Acute Post-Streptococcal Glomerulonephritis
  • Suppurative
    • Peritonsillar Abscess
    • Suppurative Otitis Media
    • Cervical Lymphadenitis
    • Acute Sinusitis
    • Mastoiditis
    • Meningitis
    • Bacteremia
    • Endocarditis
    • Pneumonia
• Symptoms
  • Stretococcal exposure in last 2 weeks (Test Sensitivity 19%, Test Specificity 91%)
  • Pharyngitis
  • Fever (Temperature >100.9)
  • Cough absent
  • Headache
  • Myalgia
• Signs
  • Anterior Cervical Lymphadenopathy
  • Palatal Petechiae (Test Sensitivity 7%, Test Specificity 95%)
  • Pharyngeal exudate (Test Sensitivity 26%, Test Specificity 88%)

Investigations

• Resp Viral PCR
  • can be used to increase confidence in the diagnosis of a viral infection and support not prescribing antibiotics for pharyngitis and tonsillitis in patients not at high risk of acute rheumatic fever
  • negative nucleic acid amplification test result may not exclude viral infection, depending on the breadth of the testing panel and the quality of the sample.
• Streptococcal Rapid Antigen Test
  • Turnaround time of 1-3 hours
  • sensitivity of 86% and specificity of 96%
  •  cost only $5-$10 compared with $30 for throat cultures
  • But unfortunately DOES NOT attract an MBS rebate.
• Throat Culture
  • can detect S. pyogenes
  • however, S. pyogenes can colonise the throat and a positive culture result does not distinguish between true S. pyogenes pharyngitis or tonsillitis and S. pyogenes carriers with pharyngitis or tonsillitis caused by a viral pathogen.
  • if a patient is at high risk of acute rheumatic fever
    • a throat swab for culture is useful to provide evidence of preceding S. pyogenes infection if the patient is later suspected to have acute rheumatic fever.
    • If possible, collect a throat swab before starting antibiotic therapy

• Antistreptolysin O titer (ASO Titer)
  • Confirms diagnosis (with serial values), but not helpful in acute disease
  • if available (repeat 10–14 days later if first test not confirmatory)
  • The false negatives rate is 20-30%, reduce false negative with anti-DNase B titre 
  • False positives can result from liver disease and tuberculosis

High-risk groups:

• Younger than 40y
  • Aboriginal and Torres Strait Islander people
  • Maori and Pacific Islander people
  • Personal history of rheumatic fever or rheumatic heart disease
  • Family history of rheumatic fever or rheumatic heart disease
• Immunosuppressed children are at increased risk of suppuratives complications
• living in a household affected by
  • overcrowding
  • experiencing socioeconomic disadvantage
• current or prior residence in, or frequent or recent travel to
  • Australian setting with a high rate of acute rheumatic fever
  • international setting with a high rate of acute rheumatic fever (eg refugees, migrants)

Diagnosis

• is a clinical diagnosis
• but can be assisted by Centor Score (Modified/McIsaac) for Strep Pharyngitis – MDCalc
  • Age – 3-14 years
  • Exudate or swelling on tonsils
  • Tender/swollen anterior cervical lymph nodes
  • Absent Cough
  • Temp >38°C (100.4°F)

Management:

• Prescribe medications in liquid form if odynophagia
• Antibiotic Course
  • Antibiotic therapy for suspected group A streptococcal pharyngitis: Antibiotic therapy is recommended only for high risk groups. 
  • Most patients who are not at high risk of acute rheumatic fever do not need antibiotics for streptococcal pharyngitis or tonsillitis
  • Small benefit of antibiotic therapy must be balanced against the potential harms (eg C diff diarrhoea, rash or more serious hypersensitivity reactions, bacterial resistance).
  • Antimicrobial recommendations may vary according to local antimicrobial susceptibility patterns; please refer to local guidelines

Dosages:

Antibiotic			Route		Dose	Duration
Phenoxymethylpenicillin			Oral		500 mg (child: 15 mg/kg up to 500 mg)	10 days
Amoxicillin			Oral		1g – (child: 50mgkg up to 1 g)  Daily     OR 500 mg – (child:  25 mg/kg) BD	10 days
	Poor compliance or oral therapy not tolerated
	Benzathine Penicillin	IM		<10 kg         450,000 units (0.9 mL) 10- <20 kg  600,000 units (1.2 mL) >20 kg      1,200,000 units (2.3 mL)		Single dose
	Hypersensitivity to penicillins (exclude immediate hypersensitivity)
	Cefalexin	Oral		25 mg/kg (max 1 g)  BD		10 days
	Anaphylaxis to beta-lactams
	Azithromycin	Oral		Children: 12 mg/kg (max 500 mg) once daily Adults:     500 mg once daily		5 days

• Phenoxymethylpenicillin
  • 500 mg (child: 15 mg/kg up to 500 mg) POy, 12-hourly for 10 days
    • S. pyogenes highly susceptible to phenoxymethylpenicillin.
    • 12-hourly dosing regimen is effective for the treatment of streptococcal pharyngitis or tonsillitis, and is preferred over more frequent dosing regimens because of improved adherence.
• Amoxicillin
  • Amoxicillin 50 mg/kg up to 1 g PO, daily for 10 days OR
  • Amoxicillin 25 mg/kg up to 500 mg PO, 12-hourly for 10 days
  • Given If amoxicillin is preferred to phenoxymethylpenicillin for a child because the liquid formulation is better tolerated
  • traditionally not given due to:
    • increased incidence of rash if the patient has undiagnosed EBV infection
    • unnecessary broader-spectrum treatment compared to phenoxymethylpenicillin
  • however, evidence suggests that amoxicillin does not significantly increase the incidence of rash in this setting
• Cefalexin
  • if delayed nonsevere hypersensitivity to penicillins
    • cefalexin 1 g (child: 25 mg/kg up to 1 g) PO, 12-hourly for 10 days
• Azithromycin
  • if immediate (nonsevere or severe) or delayed severe hypersensitivity to penicillins
  • Azithromycin 500 mg (child: 12 mg/kg up to 500 mg) PO, daily for 5 days
• Benzathine benzylpenicillin IM
  • As a single dose
  • Can be used in those who may experience difficulties adhering to the 10-day oral regimen.
  • Is long acting and provides adequate concentrations of benzylpenicillin for up to 4 weeks, so only a single dose is required.
  • Do not confuse benzathine benzylpenicillin with benzylpenicillin, which is short acting
    • adult: 1.2 million units (2.3 mL)
    • child less than 10 kg: 0.45 million units (0.9 mL)
    • child 10 kg to less than 20 kg: 0.6 million units (1.2 mL)
    • child 20 kg or more: 1.2 million units (2.3 mL)
• Adherence
  • full 10-day oral regimen is important for patients at high risk of acute rheumatic fever if aiming to eradicate S. pyogenes from the pharynx and prevent the development of acute rheumatic fever.
  • However, for patients not at high risk of acute rheumatic fever who are being treated for symptom benefit, stopping therapy after 5 days is reasonable if symptoms have resolved and microbiological cure is not needed.
  • Azithromycin has a long intracellular half-life, so 5 days of therapy is sufficient in all patients.
• Rash
  • caused by
    • Antimicrobial hypersensitivity
    • Viral exanthem due to EBV infection
      • underlying mechanism of the rash is still not well understood
      • most commonly proposed mechanism is a transient virus-mediated immune alteration, resulting in the development of a reversible, delayed-type hypersensitivity reaction to the antibiotics

Efficacy: Benefits of Antibiotic Treatment

• Prevents Rheumatic Fever
  • Antibiotics decrease Rheumatic Fever Incidence by 90%
  • Effective if given in first 9 days of infection
  • Number Needed to Treat: 3000-4000 patients treated to prevent one case Rheumatic Fever
    • Data is based on 1940s data, and some estimates estimate NNT at over 1 Million
• Prevents suppurative complications
  • Peritonsillar Abscess (variable evidence, NNT 50 to 225)
  • Acute Sinusitis
  • Suppurative Otitis Media (NNT 1 in 200)
  • Cervical Lymphadenitis
• Decreases epidemic spread
• Decreases duration of disease by about 1 day
• Does NOT prevent Post-Streptococcal Glomerulonephritis (PSGN)

Consider consultation with paediatric/ENT outpatient follow-up when

• Recommendations may differ, please refer to local referral guidelines
• 4 or more episodes in the last 12 months
• 4 episodes per year for 2 consecutive years
• 3 episodes per year for 3 consecutive years
• more than 2 weeks missed for school or parents attendance at work
• history of quinsy
• clinical modifiers may impact the categorisation of the patient:
  • Impact on employment/education/home/activities of daily living functioning/personal frailty or safety/Identifies as Aboriginal and/or Torres Strait Islander

Management of suppurative complications

Disease	Management
Peritonsillar abscess (Quinsy)
Odynophagia/Dysphagia (pooling/drooling) “Hot potato” voice Trismus Peritonsillar swelling/erythema Uvula deviation	Refer to ENT for consideration of drainage Antibiotics: Benzylpenicillin 50 mg/kg (max 1.2 g) IV 6 hourly Switch to oral therapy: Phenoxymethylpenicillin 15 mg/kg (max 500 mg) oral twice daily to complete a total of 10 days of therapy (IV + oral inclusive)
Retropharyngeal/Parapharyngeal abscess
Fever Odynophagia/Dysphagia Neck swelling/tenderness (particularly in young infants) Torticollis/Neck stiffness Retropharyngeal bulge	Refer to ENT for consideration of imaging and ongoing management Investigations: Lateral neck X-ray: normal X-ray does not exclude the diagnosis CT with IV contrast is the imaging modality of choice when required.  (Should only be performed with advanced airway management available) Antibiotics: Amoxicillin/Clavulanic acid 25 mg/kg (max 1 g) IV 8 hourly Switch to oral therapy: Amoxicillin/Clavulanic acid 22.5 mg/kg (max 875 mg) oral twice daily
Epiglottitis/Bacterial Tracheitis
Abrupt onset Respiratory distress High grade fever Toxic looking Odynophagia/Dysphagia Stridor Muffled “hot-potato” voice Tripod position with neck extension Cervical lymphadenopathy **increased risk in children unimmunised to Hib**	Minimal handling : Defer all invasive examination/procedures/imaging until advanced airway management available Early ICU/anaesthetic/ENT review Antibiotics: Ceftriaxone 50 mg/kg (max 1 g) IV/IM daily for 5 days Consider: Dexamethasone 0.15 mg/kg (max 10 mg) oral/IV/IM/ stat, repeat in 24 hours prn

• Etiologies for recurrent Streptococcal Pharyngitis
  • Poor Compliance with oral medications (most common)
    • Day 3: 50% stopped antibiotics
    • Day 6: 70% stopped antibiotics
    • Day 9: 80% stopped antibiotics
  • Repeat exposure in crowded conditions
    • School
    • Daycare
    • Home or workplace
  • Eradicated protective throat flora by prior antibiotic
    • a-hemolytic Streptococcus is protective normal flora
    • Cephalosporins apparently do less harm
  • Selected beta-lactam resistance by prior antibiotic
    • Consider Augmentin for 10 day course
    • Suppressed Immune response from prior antibiotics
  • Antibiotic Resistance
    • Penicillin resistance is infrequent in Strep Throat
  • Chronic Pharyngeal Carriage of Streptococcus pyogenes
  • Pharyngitis due to another cause