What causes left-sided throat pain and how is it treated?

Left-Sided Throat Pain: Causes and Treatment

For unilateral (left-sided) throat pain, you must immediately rule out life-threatening complications—particularly peritonsillar abscess, retropharyngeal abscess, epiglottitis, and Lemierre syndrome—before attributing symptoms to benign pharyngitis. 1

Critical Red Flags Requiring Urgent Evaluation

The lateralization of throat pain is a key warning sign that demands immediate assessment for serious complications:

Peritonsillar Abscess

• Look for: Unilateral tonsillar swelling (left side in this case), uvular deviation away from the affected side, trismus (difficulty opening mouth), "hot potato voice," and difficulty swallowing 1
• This requires immediate evaluation and drainage, not antibiotics alone 1

Retropharyngeal Abscess

• Look for: Neck stiffness, neck tenderness or swelling, drooling, and difficulty swallowing 1
• This is a surgical emergency requiring urgent imaging and intervention 1

Epiglottitis

• Look for: Drooling, stridor, patient sitting forward, and respiratory distress 1
• Airway management is paramount to survival—do not delay for imaging if clinical suspicion is high 2
• Avoid examining the throat with a tongue depressor if epiglottitis is suspected, as this can precipitate complete airway obstruction 2

Lemierre Syndrome

• Consider in: Adolescents and young adults with severe pharyngitis that progresses to septic thrombophlebitis of the internal jugular vein 1, 3
• Caused by Fusobacterium necrophorum and can present with unilateral throat pain, fever, and subsequent septic emboli to lungs 3

When Symptoms Are Chronic (>2 Weeks)

If left-sided throat pain persists beyond 2 weeks, shift your diagnostic approach:

Non-Infectious Causes to Investigate

• Malignancy: Particularly in elderly patients with isolated persistent unilateral symptoms—this is a critical diagnosis not to miss 1
• GERD: Can present as chronic throat irritation without classic heartburn 1
• Do NOT use rapid antigen tests or throat cultures in chronic presentations, as these are designed for acute bacterial pharyngitis 1
• Do NOT use Centor or McIsaac scores—these are not validated for chronic symptoms 1

Acute Presentations (<14 Days)

For acute left-sided throat pain without red flags:

Diagnostic Approach

• Use the Centor score to assess likelihood of Group A Streptococcal infection: fever, tonsillar exudates, tender anterior cervical lymphadenopathy, absence of cough 4
• 0-2 Centor criteria: No antibiotics or testing needed 4
• 3-4 Centor criteria: Consider rapid antigen testing; if positive, antibiotics may provide modest benefit (shortens symptoms by approximately 16 hours) 4

Treatment Algorithm

Symptomatic Management (All Patients):

• First-line: Ibuprofen or acetaminophen for pain relief 4
• Ibuprofen 400 mg is more effective than acetaminophen 1000 mg for throat pain relief 5
• Avoid aspirin in children due to Reye syndrome risk 4
• Exercise caution with NSAIDs in elderly patients due to cardiovascular, renal, and GI risks 1

Antibiotics (Only if 3-4 Centor Criteria):

• First choice: Penicillin V, twice or three times daily for 5-7 days 4, 6
• Penicillin allergy: Clarithromycin (preferred over azithromycin due to lower resistance rates) 4
• Do NOT prescribe antibiotics to prevent rheumatic fever, glomerulonephritis, or suppurative complications in low-risk patients 4

Corticosteroids:

• Not routinely recommended for acute pharyngitis 4
• May be considered in adults with severe presentations (3-4 Centor criteria) in conjunction with antibiotics, but benefit is minimal (reduces pain duration by only ~5 hours) 4

Common Pitfalls to Avoid

• Never assume unilateral throat pain is "just pharyngitis" without examining for abscess or other complications 7, 2
• Never prescribe empiric antibiotics for chronic throat pain without identifying the underlying cause 1
• Never delay evaluation if patient has severe pain with normal oropharyngeal exam—consider indirect laryngoscopy to evaluate for supraglottitis or lingual tonsillitis 7
• Never continue standard acute pharyngitis management beyond 2 weeks without investigating alternative diagnoses 1