What is the recommended dose of dexamethasone (corticosteroid) for managing swollen tonsils and sore throat in adults?

Dexamethasone Dosing for Acute Pharyngitis with Swollen Tonsils

For adults with severe sore throat (Centor score 3-4), administer a single oral dose of dexamethasone 10 mg in conjunction with antibiotic therapy when indicated. 1, 2

Clinical Context and Evidence Base

The use of corticosteroids for acute pharyngitis is not routine but reserved for severe presentations. 1, 2 The American College of Physicians and European Society of Clinical Microbiology and Infectious Diseases both recommend considering corticosteroids only in adults with severe presentations (3-4 Centor criteria: fever, tonsillar exudates, tender anterior cervical lymphadenopathy, absence of cough). 1, 2

Dosing Specifications

Single-dose regimen:

• Oral dexamethasone: 10 mg (single dose) 3, 4
• Intramuscular dexamethasone: 10 mg (if oral route not feasible) 4
• Both routes show equivalent efficacy for pain relief 4

The 10 mg dose is based on corticosteroid equivalency principles, where dexamethasone is 25 times more potent than hydrocortisone. 5 This dose provides adequate anti-inflammatory effect without requiring weight-based calculations in adults. 3, 4

Expected Clinical Benefits

Symptom relief timeline:

• Pain relief onset: 4 hours earlier compared to placebo 4
• Complete symptom resolution at 48 hours: 35.4% vs 27.1% (dexamethasone vs placebo) 3
• No significant benefit at 24 hours in adults 3

The mechanism involves reduction of pharyngeal inflammation and swelling through anti-inflammatory properties. 5

Critical Decision Algorithm

Step 1: Assess severity using Centor criteria

• 0-2 criteria: Do NOT use corticosteroids; recommend ibuprofen or paracetamol only 1, 2
• 3-4 criteria: Consider corticosteroids in conjunction with appropriate antibiotic therapy 1, 2

Step 2: Exclude contraindications

• Diabetes mellitus or glucose dysregulation 5
• Patients already on exogenous steroids 5
• Endocrine disorders 5

Step 3: Administer single dose

• Give dexamethasone 10 mg orally once 3, 4
• Combine with antibiotic therapy if bacterial pharyngitis suspected 1, 2
• Prescribe ibuprofen or paracetamol for ongoing symptom management 1, 2

Important Caveats and Pitfalls

Do NOT use corticosteroids routinely for all sore throats—the effect is modest and primarily benefits severe presentations. 1, 2 Studies were not adequately powered to detect adverse effects of short-course steroids, so exercise caution. 1

Oral administration may be less effective than other routes based on systematic review data, though the 10 mg oral dose has demonstrated clinical benefit in randomized trials. 1, 3

Bacterial pathogen identification matters: Patients with confirmed bacterial pharyngitis show significantly better response to dexamethasone compared to those without identified pathogens. 4

Pediatric Dosing (for reference)

In children with moderate to severe pharyngitis, the dose is 0.6 mg/kg oral dexamethasone with a maximum of 10 mg as a single dose. 6, 7 Children show earlier pain relief (9.2 vs 18.2 hours) and faster complete resolution (30.3 vs 43.8 hours) compared to placebo. 7

What NOT to Do

• Avoid zinc gluconate—not recommended for sore throat treatment 1, 2
• Do not prescribe steroids for hoarseness/dysphonia without proper evaluation (preponderance of harm) 1
• Do not use steroids in patients with Centor 0-2—no demonstrated benefit 1, 2
• Never use steroids as monotherapy in severe bacterial pharyngitis—always combine with appropriate antibiotics 1, 2