Conjunctivitis (Pink Eye)

Conjunctivitis, commonly called "pink eye," is inflammation of the conjunctiva—the clear membrane covering the white of the eye and lining the inner eyelids. It's one of the most common eye conditions and has several different causes, each requiring different management.

Types of Conjunctivitis

Viral Conjunctivitis

Most common type:

• Usually caused by adenovirus
• Highly contagious
• Often starts in one eye, spreads to the other
• Associated with upper respiratory infection
• Watery discharge
• Resolves in 1-2 weeks without antibiotics

Bacterial Conjunctivitis

• Caused by bacteria (Staphylococcus, Streptococcus, Haemophilus)
• Moderate contagiousness
• Thick, yellow-green discharge
• Often "glues" eyelids shut overnight
• May respond faster with antibiotic drops
• Can resolve on its own in mild cases

Allergic Conjunctivitis

• Not contagious
• Caused by allergens (pollen, dust, pet dander)
• Intense itching is hallmark symptom
• Usually affects both eyes
• Often with other allergy symptoms (sneezing, runny nose)
• Seasonal or perennial

Other Types

• Giant papillary conjunctivitis—contact lens related
• Chemical/irritant conjunctivitis—exposure to irritants
• Gonococcal/chlamydial conjunctivitis—sexually transmitted, serious

Symptoms

Common to All Types

• Red or pink appearance
• Eye irritation or discomfort
• Tearing
• Discharge (varies by type)
• Swelling of conjunctiva or eyelids

By Type

Viral:

• Watery discharge
• One eye first, then second
• Swollen lymph node in front of ear
• Recent cold symptoms

Bacterial:

• Thick, purulent (yellow-green) discharge
• Lids stuck together in morning
• Can affect one or both eyes

Allergic:

• Intense itching (distinguishing feature)
• Stringy, mucoid discharge
• Both eyes equally affected
• Puffy eyelids
• Associated sneezing, congestion

When to Seek Care

How Conjunctivitis Is Diagnosed

Clinical Examination

• Assessment of discharge type
• Evaluation of conjunctiva
• Check for lymph node swelling
• Vision testing
• Slit-lamp examination if needed

When Testing May Be Done

• Severe or atypical cases
• Not responding to treatment
• Suspected gonococcal or chlamydial infection
• Neonatal conjunctivitis

Treatment

Viral Conjunctivitis

Supportive care (no antibiotics help):

• Cool compresses
• Artificial tears for comfort
• Usually resolves in 1-2 weeks
• Stay home from work/school while symptomatic
• Highly contagious for 10-14 days

Bacterial Conjunctivitis

Mild cases may resolve without treatment

Antibiotic drops when indicated:

• Erythromycin ointment
• Fluoroquinolone drops (moxifloxacin, ofloxacin)
• Polymyxin B/trimethoprim drops
• Usually improves in 2-3 days

Allergic Conjunctivitis

Allergen avoidance

Medications:

• Antihistamine drops (ketotifen, olopatadine)
• Mast cell stabilizers
• Artificial tears to wash out allergens
• Cool compresses
• Oral antihistamines if needed

Severe cases:

• Short-term steroid drops (with doctor supervision)

Contact Lens-Related

• Stop wearing contacts until resolved
• Dispose of current lenses and case
• May need antibiotic drops
• Follow-up before resuming lens wear

Prevention and Hygiene

Preventing Spread

• Wash hands frequently and thoroughly
• Don't touch or rub your eyes
• Don't share towels, washcloths, or pillows
• Don't share eye makeup or contact lens solutions
• Change pillowcases daily during infection
• Dispose of eye makeup used during infection
• Stay home while contagious (viral: 10-14 days; bacterial: 24-48 hours after starting antibiotics)

For Contact Lens Wearers

• Don't wear contacts during infection
• Discard lenses worn during infection
• Replace lens case
• Wait until fully recovered before resuming

Frequently Asked Questions

How can I tell if it's viral or bacterial?

Viral: watery discharge, one eye first, often with cold symptoms, may have swollen lymph node by ear. Bacterial: thick yellow-green discharge, lids stuck shut in morning. However, distinguishing can be difficult, and some cases need professional evaluation.

Do I need antibiotics?

Viral conjunctivitis doesn't respond to antibiotics—it needs to run its course. Bacterial conjunctivitis may resolve on its own, but antibiotics can speed recovery and reduce contagiousness. Allergic conjunctivitis needs allergy treatment, not antibiotics.

How long am I contagious?

Viral: typically 10-14 days from symptom onset. Bacterial: until 24-48 hours after starting antibiotic drops, or about 5-7 days if untreated. Allergic conjunctivitis is not contagious.

Can I go to work or school?

With viral or bacterial conjunctivitis, it's best to stay home while symptomatic and contagious. Children should stay home from school. Allergic conjunctivitis is not contagious, so isolation isn't needed.

Should I throw away my makeup?

Yes, discard any eye makeup (mascara, eyeliner) used during the infection, as it can harbor bacteria or viruses and cause reinfection.

Why do I keep getting conjunctivitis?

Recurrent conjunctivitis may be due to allergies (seasonal patterns), underlying eyelid conditions (blepharitis), chronic dry eye, or environmental factors. See an eye doctor if conjunctivitis keeps returning.

References