Acute Pharyngitis

Acute Pharyngitis

I. Definition

Acute Pharyngitis is an inflammatory syndrome of the pharynx and/or tonsils (pharyngotonsillitis) caused by infectious agents.

• It is one of the most common reasons for pediatric outpatient visits.
• Peak Age: 5–15 years (School-going age).

II. Etiology

1. Viral (Most Common - 70–80%):
   • Adenovirus (Pharyngoconjunctival fever).
   • Enterovirus (Herpangina - Coxsackie A).
   • EBV (Infectious Mononucleosis).
   • Influenza, Parainfluenza, Rhinovirus.
2. Bacterial (20–30%):
   • Group A Beta-Hemolytic Streptococcus (GABHS/GAS): The clinically most significant pathogen due to sequelae.
   • Group C & G Streptococcus.
   • Arcanobacterium haemolyticum (Scarlatiniform rash in adolescents).
   • Mycoplasma pneumoniae, Chlamydia pneumoniae.
   • Corynebacterium diphtheriae (Rare, membranous).

III. Clinical Features

Differentiation is primarily between Viral and Bacterial (GAS) causes, though clinical overlap exists.

A. Suggestive of Viral Pharyngitis:

• Onset: Gradual.
• Associated URI Signs: Cough, Coryza (Runny nose), Hoarseness, Conjunctivitis.
• Systemic: Viral exanthem, diarrhea.
• Oral: Ulcers or vesicles (e.g., Herpangina on soft palate).

B. Suggestive of Bacterial (GABHS) Pharyngitis:

• Onset: Sudden onset of sore throat and high fever.
• Absence of Cough/Coryza.
• Constitutional: Headache, Abdominal pain, Vomiting.
• Examination Signs:
  • Pharynx: Erythema, tonsillar exudates (patchy/follicular).
  • Palate: Palatal Petechiae ("Donut lesions").
  • Tongue: Strawberry tongue (if Scarlet fever).
  • Nodes: Tender Anterior Cervical Lymphadenopathy.
  • Rash: Scarlatiniform (sandpaper) rash.

IV. General Diagnosis

• Diagnosis is clinical for viral cases.
• Specific testing (RADT/Culture) is reserved for suspected GABHS (See Part II).
• CBC: Lymphocytosis with atypical cells suggests EBV (Mononucleosis).

V. General Management

• Viral: Self-limiting (3–7 days).
• Supportive Care (Mainstay):
  • Analgesia/Antipyretics: Paracetamol (10-15 mg/kg) or Ibuprofen for odynophagia.
  • Hydration: Adequate oral fluids; cold liquids/popsicles may be soothing.
  • Salt water gargles: For older children.
  • Avoid: Antibiotics in clear viral cases (prevents resistance).

Diagnosis & Management of Suspected Streptococcal Pharyngitis

The primary goal is identifying GABHS to prevent Rheumatic Fever (RF).

I. Diagnostic Approach

Testing is indicated only if clinical suspicion is moderate-to-high.

Step 1: Clinical Probability Assessment (Modified Centor / McIsaac Score)

• Criteria:
  1. Fever > 38°C (+1)
  2. Absence of Cough (+1)
  3. Tender Anterior Cervical Adenopathy (+1)
  4. Tonsillar Swelling or Exudate (+1)
  5. Age 3–14 years (+1)
  6. Age > 45 years (-1)

Step 2: Decision Algorithm

• Score ≤ 2: Viral likely. No Testing, No Antibiotics.
• Score ≥ 3: Testing Indicated (RADT or Culture).
• Note: In high-prevalence RF settings (like India), some guidelines allow empirical treatment for Score ≥4 if testing is unavailable.

Step 3: Confirmatory Testing

1. Rapid Antigen Detection Test (RADT):
   • Specific (>95%) but less sensitive.
   • Positive: Treat as Strep.
   • Negative: Must confirm with Throat Culture in children/adolescents.
2. Throat Culture (Gold Standard):
   • Swab both tonsils and posterior pharyngeal wall.
   • Standard for confirmation if RADT is negative.

II. Management of Confirmed GABHS

Goal: Prevent Rheumatic Fever (effective if started within 9 days of onset), reduce suppurative complications, and shorten illness.

A. Antibiotic Therapy (Primary Prevention of RF)

1. First Line (Oral):
   • Amoxicillin: 50 mg/kg/day (Max 1000 mg) Once daily or BD for 10 days.
   • Penicillin V: Oral for 10 days.
2. First Line (Intramuscular):
   • Benzathine Penicillin G: Single dose.
     • < 27 kg: 600,000 Units.
     • > 27 kg: 1.2 Million Units.
     • Advantage: Ensures compliance (Gold standard for non-compliant patients).
3. Penicillin Allergy:
   • Non-anaphylactic: First-generation Cephalosporin (Cephalexin) for 10 days.
   • Anaphylactic: Azithromycin (12 mg/kg OD for 5 days) or Clindamycin.

B. Isolation

• Child is non-infectious after 24 hours of appropriate antibiotic therapy and can return to school.

C. Follow-up

• Repeat culture (Test of Cure) is not recommended for uncomplicated cases.
• Treat "carriers" (chronic colonization) only if there is a history of RF in the family or community outbreaks.