How do you differentiate the treatment for conjunctivitis and blepharitis?

Differentiating Treatment for Conjunctivitis vs. Blepharitis

Treatment for conjunctivitis and blepharitis should be directed at the underlying cause, with blepharitis requiring eyelid hygiene as the foundation of treatment, while conjunctivitis treatment varies based on its infectious or allergic etiology. 1

Diagnostic Differentiation

Conjunctivitis

• Primary symptoms: Redness of the conjunctiva, discharge, tearing, foreign body sensation
• Key diagnostic features:
  • Viral: Watery discharge, preauricular lymphadenopathy, often unilateral initially
  • Bacterial: Purulent discharge, crusting of eyelids, bilateral involvement
  • Allergic: Severe itching, bilateral involvement, history of allergies

Blepharitis

• Primary symptoms: Burning, irritation, foreign body sensation, crusting along eyelid margins
• Key diagnostic features:
  • Anterior (staphylococcal): Crusting at base of lashes, collarettes, eyelid margin erythema
  • Posterior (MGD): Thickened eyelid margins, pouting/capping of meibomian gland orifices, abnormal meibomian secretions
  • Demodex: Cylindrical dandruff at base of lashes

Treatment Approaches

Conjunctivitis Treatment

1. Viral Conjunctivitis

   • Primarily supportive care as condition is self-limiting 1
   • Cold compresses for symptomatic relief
   • Artificial tears for lubrication
   • Avoid antibiotics as they are ineffective against viral causes 1

2. Bacterial Conjunctivitis

   • Most uncomplicated cases are self-limiting and may not require antibiotics 1
   • For moderate to severe cases or when expedited resolution is desired:
     • Topical antibiotics such as bacitracin ointment 1-3 times daily 2 or moxifloxacin 0.5% drops 3 times daily for 7 days 3
   • For gonococcal conjunctivitis: Systemic antibiotics plus topical therapy 1

3. Allergic Conjunctivitis

   • Topical antihistamines and mast cell stabilizers 4
   • Short-term topical corticosteroids for severe inflammation 1
   • Allergen avoidance when possible

Blepharitis Treatment

1. Foundation: Eyelid Hygiene 5

   • Warm compresses for 10-15 minutes, 3-4 times daily
   • Gentle cleansing of eyelid margins with diluted baby shampoo or commercial eyelid cleaners
   • For posterior blepharitis/MGD: Include vertical eyelid massage to express meibomian glands

2. Anterior Blepharitis (Staphylococcal/Seborrheic)

   • Topical antibiotics: Bacitracin or erythromycin ointment applied to eyelid margins 1-3 times daily for 5-7 days 5, 2
   • Focus on removing crusting from eyelashes

3. Posterior Blepharitis (MGD)

   • Warm compresses and eyelid massage are essential
   • For persistent cases: Oral antibiotics (doxycycline, minocycline) with anti-inflammatory properties 5
   • Caution: Tetracyclines are contraindicated in pregnancy, nursing women, and children under 8 years 5

4. Demodex Blepharitis

   • Tea tree oil-based cleansers
   • Lotilaner for Demodex-related blepharitis 5

Special Considerations

Overlapping Conditions

• Blepharitis and conjunctivitis frequently coexist as blepharoconjunctivitis 1
• When both conditions are present, treat the underlying blepharitis first as it may be the source of conjunctival inflammation 1

Complications to Monitor

• Conjunctivitis: Corneal involvement, especially in cases of gonococcal or chlamydial infection
• Blepharitis: Eyelash loss, eyelid scarring, corneal scarring and neovascularization 1
• Phlyctenular keratoconjunctivitis: Can develop as a hypersensitivity reaction to staphylococcal antigens in blepharitis 6

Treatment Algorithm

1. Determine primary condition:

   • If primarily conjunctival inflammation → treat as conjunctivitis
   • If primarily eyelid margin involvement → treat as blepharitis
   • If both present → address blepharitis first

2. For conjunctivitis:

   • Viral → supportive care only
   • Bacterial (mild) → observation or topical antibiotics
   • Bacterial (severe) → topical antibiotics
   • Allergic → antihistamines/mast cell stabilizers

3. For blepharitis:

   • All types → eyelid hygiene (warm compresses + cleansing)
   • Anterior → add topical antibiotics
   • Posterior/MGD → add oral antibiotics for persistent cases
   • Demodex → add tea tree oil or lotilaner

Common Pitfalls to Avoid

1. Overuse of antibiotics for viral conjunctivitis or mild bacterial conjunctivitis 1, 7
2. Neglecting eyelid hygiene in blepharitis treatment, which is the cornerstone of therapy 5
3. Failure to identify underlying systemic conditions such as rosacea that may contribute to blepharitis 1
4. Long-term corticosteroid use without monitoring for complications
5. Missing serious causes of red eye such as acute angle-closure glaucoma, uveitis, or keratitis

Remember that blepharitis is typically chronic and requires long-term management, while most cases of conjunctivitis are acute and self-limiting 1, 5.