Bacterial Conjunctivitis: Symptoms and Discharge

The most characteristic sign of bacterial conjunctivitis is purulent discharge — thick, yellowish or greenish, and re-forming after you wipe it away — that glues the eyelids shut overnight. Redness, tearing, and swollen eyelids come with it. Acute conjunctivitis of all causes is estimated to affect 6 million people a year in the United States, and the bacterial form is the one most commonly diagnosed at red-eye visits in primary care.

Symptoms of bacterial conjunctivitis

• Purulent or mucopurulent discharge, thick enough to stick to the lashes, the most typical sign
• Eyelids glued shut on waking, from discharge building up overnight
• Redness of the whole conjunctiva
• Tearing and swollen eyelids
• A gritty or foreign-body feeling in the eye
• Usually starts in one eye and may spread to the other

Itching is typically absent in the bacterial form — that absence is one of the discriminators. StatPearls reports three findings that predict a bacterial cause: glued eyelids, lack of itching, and no previous history of conjunctivitis. In children, ask about ear pain too: bacterial conjunctivitis and acute otitis media often turn up together.

What causes bacterial conjunctivitis

The organisms differ by age. In children, the most common is Haemophilus influenzae, followed by Streptococcus pneumoniae and Moraxella catarrhalis. In adults and older adults, staphylococcal species predominate, Staphylococcus aureus included. Contact lens wearers are more susceptible to gram-negative organisms, which is one reason their red eye is handled differently.

Transmission happens through direct contact with hands, discharge from the infected eye, contaminated objects — shared towels, pillowcases, makeup — and respiratory droplets. Cases peak from December through April.

Bacterial vs. viral conjunctivitis: differences in discharge

The classic split is purulent discharge for bacteria against watery discharge for viruses, and it holds often enough to be useful — but StatPearls notes a 2003 study that found discharge characteristics alone did not reliably correlate with the cause. The more discriminating pattern is the whole picture: glued lids in the morning with no itching leans bacterial; a tender lymph node in front of the ear, a recent cold, and itchy watery eyes lean viral.

Treatment and care

1. Know that watchful waiting is a legitimate option. Untreated, uncomplicated bacterial conjunctivitis resolves within about a week. Topical antibiotics shorten symptoms, cut transmission, and speed the return to school or work — but they are a choice, not an automatic prescription, and over-prescribing is the documented problem in this diagnosis.
2. Get antibiotics if you fall in a complicated group: contact lens wearers, people who are immunocompromised, and any suspected gonococcal or chlamydial infection, which needs systemic treatment, not just drops.
3. Clean the discharge with gauze or cotton dampened in water or saline, always with clean hands, wiping from the inner to the outer corner of the eye.
4. Wash your hands often, especially after touching your eyes, to avoid spreading the infection to the other eye or to other people.
5. Take contact lenses out and leave them out until the treatment course is finished and symptoms are gone.
6. Finish the course if you start one — the usual duration is five to seven days. If there is no improvement after one to two days, go back rather than waiting it out.

Children who start treatment can generally return to regular school activities; individual school policies still apply.

When to seek care more urgently

Referral to an eye doctor is the recommendation when there is vision loss, no response to treatment, recurrent infections, corneal involvement, or severe pain or discharge. A hyperacute case — copious pus with sudden onset and rapid progression — suggests gonococcal infection and is handled urgently. Complications are uncommon but real: severe infections can cause keratitis, corneal ulceration and perforation, and blindness.

This content is informational and does not replace medical consultation, diagnosis, or treatment. See the overview in conjunctivitis symptoms: signs, types, what to do, compare with viral conjunctivitis symptoms or, if the main symptom is just redness, see red eye: what it could be.