Pink Eye (Conjunctivitis): Viral vs Bacterial vs Allergic — What Needs Antibiotics

What is “pink eye”—and what are the three common causes?

“Pink eye” (conjunctivitis) is inflammation of the eye’s surface. The big three are viral, bacterial, and allergic. Viral and allergic types usually cause watery discharge; bacterial often causes pus/mucus with the eyelids matted shut after sleep. No single symptom perfectly separates them—history and exam patterns guide the diagnosis.

Viral conjunctivitis: how does it behave and what helps?

Typical with colds or after close contact; starts in one eye and may spread to the other. It’s contagious and self-limited. Home care: cold compresses, preservative-free artificial tears, strict hand hygiene, and no contact lenses until fully well. Antibiotics don’t help viral pink eye.

Allergic conjunctivitis: what’s first-line?

Dominant symptom = itching; usually both eyes; often with sneezing or nasal allergies. First-line is an antihistamine + mast-cell stabilizer drop such as ketotifen (OTC). If symptoms persist, olopatadine is a common prescription option. Cool compresses and preservative-free tears help; treat nasal allergies in parallel.

Bacterial conjunctivitis: when are antibiotics actually needed?

Most mild cases can improve without antibiotics, but drops/ointment may shorten illness and reduce spread. Antibiotics are more appropriate when you have frank pus, eyelids glued shut, immunocompromise, suspected gonorrhea/chlamydia, or you wear contact lenses (higher risk for corneal infection).

Which antibiotic drops does TeleDirectMD typically use (adults)?

For non–contact lens adults with straightforward bacterial conjunctivitis, we typically use erythromycin ophthalmic ointment or trimethoprim–polymyxin B drops. Contact lens wearers require antipseudomonal coverage (a fluoroquinolone drop) and an urgent in-person eye evaluation to rule out keratitis. We avoid steroid eye drops unless an eye specialist directs them.

I wear contact lenses—what should I do?

Remove lenses immediately and do not reinsert until symptoms are completely gone. Dispose of or disinfect lenses and cases. Because lens wear raises the risk of bacterial keratitis, clinicians use topical antibiotics and arrange prompt ophthalmology evaluation.

How contagious is pink eye—and how do I avoid spreading it?

Viral and bacterial types spread easily through hands, towels, pillowcases, makeup, and contact lenses. Wash hands often, avoid eye rubbing, don’t share eye products, and stay out of pools while symptomatic. Allergic conjunctivitis is not contagious.

When should I be seen in person right away?

Go same-day if you have moderate–severe eye pain, light sensitivity, reduced or blurry vision that doesn’t clear after wiping discharge, trauma or chemical exposure, vesicular rash on the eyelids/near the eye, contact lens wear with pain, or symptoms that worsen or fail to improve.

Can TeleDirectMD treat pink eye by video?

Yes—adults (18+), video-only, cash-pay. We’ll determine the likely cause, give a precise home-care plan, prescribe drops only when indicated, and set a follow-up/return-to-care plan. (No controlled substances.)

Practical plan (copy/paste)

·         Stop contact lenses until fully resolved; replace or disinfect lenses and case.

·         Viral/allergic: cold compresses + preservative-free artificial tears.

·         Allergic first-line: ketotifen twice daily; consider prescription olopatadine if still symptomatic.

·         Bacterial (non-contact lens): likely erythromycin ointment or trimethoprim–polymyxin B drops if antibiotics are appropriate.

·         Bacterial (contact lens): fluoroquinolone drop and urgent in-person eye exam.

·         Avoid steroid eye drops unless an eye specialist tells you to use them.

·         Hygiene: handwashing, separate towels, fresh pillowcases, no makeup/false lashes until recovered.

Myth vs Reality

·         Myth: All pink eye needs antibiotics. → Reality: Viral and allergic types don’t benefit from antibiotics.

·         Myth: Yellow discharge always means bacterial. → Reality: Viral can have mucus too; pattern and risk factors matter.

·         Myth: Contact lenses are fine once redness improves. → Reality: Avoid lenses until fully resolved; lens wear raises keratitis risk.

·         Myth: Steroid drops calm pink eye safely. → Reality: Steroids can worsen infections—specialist-only.

·         Myth: Allergic pink eye is contagious. → Reality: Allergic conjunctivitis is not contagious.

Evidence & Further Reading (Last verified: August 22, 2025)

·         CDC — Clinical overview of conjunctivitis (HCP)

·         CDC — How to treat pink eye (patient)

·         AAFP (2024) — Conjunctivitis: Diagnosis & Management

·         AAO — Conjunctivitis Preferred Practice Pattern (2023)

·         Cochrane Review (2023) — Antibiotics vs placebo for acute bacterial conjunctivitis

StatPearls (2024) — Bacterial Conjunctivitis