Purulent Conjunctivitis (Eye Pus): Bacterial, Viral, Allergic, Chemical Causes

Pus in the Eyes: Etiologies

Purulent discharge indicates active inflammation/infection.

Bacterial Conjunctivitis (Most Common)

• Pathogens: S. pneumoniae, H. influenzae, M. catarrhalis, S. aureus.
• Symptoms: Red eye, thick yellow-green discharge, crusting, mild pain.
• Treatment: Topical antibiotics (fluoroquinolone, aminoglycoside, polymyxin/trimethoprim) × 5–7 days.

Viral Conjunctivitis

• Adenovirus (epidemic keratoconjunctivitis), enterovirus, HSV.
• Watery/mucoid discharge, follicles, preauricular node; bilateral.
• Supportive: cold compresses, artificial tears; antivirals for HSV.

Allergic Conjunctivitis

• Itching, watery discharge, chemosis; seasonal/perennial.
• Rarely purulent unless secondary infection.
• Antihistamine/mast cell stabilizer drops.

Chemical Conjunctivitis

• Acid/alkali splash, irritants (chlorine, smoke).
• Immediate irrigation (15–30 min) → emergency referral.

When to See an Eye Doctor

• Vision change, severe pain, photophobia
• Contact lens wearer
• Neonate (ophthalmia neonatorum—emergency)
• No improvement in 48 hrs