Pink Eye Treatment in Bangkok: Conjunctivitis Care, Viral, Bacterial and Allergic
How Doctor Bangkok diagnoses conjunctivitis correctly and avoids unnecessary antibiotic drops.
Clinically reviewed by Dr. Ponlawat Pitsuwan, Physician, Doctor Bangkok
Pink eye, or conjunctivitis, is inflammation of the conjunctiva and is usually viral, bacterial, or allergic. Most viral cases are highly contagious and resolve in 1 to 2 weeks without antibiotics. Bacterial conjunctivitis is less common in adults and responds to short-course topical antibiotics. Allergic conjunctivitis needs antihistamine drops, not antibiotics. Doctor Bangkok identifies the type at the first visit so you get the right treatment and stop spreading it to others.
From the clinic: More than half the prescriptions for antibiotic eye drops I see in Bangkok are for viral conjunctivitis that would have settled on its own. The useful question is not whether to prescribe drops; it is which kind of conjunctivitis you have. The clinical exam takes under five minutes and decides the whole management plan.
The three types of conjunctivitis
Viral conjunctivitis, usually adenoviral, causes watery discharge, burning, and often starts in one eye before spreading to the other. It commonly follows or accompanies a cold or sore throat. Bacterial conjunctivitis produces thick yellow or green discharge that re-accumulates within minutes of wiping and may glue the lashes together in the morning. Allergic conjunctivitis is bilateral from the start, intensely itchy, and comes with clear watering and often a runny nose, most obvious in pollen or dust exposure. The pattern of discharge, itch, and laterality usually decides the diagnosis without lab tests.
| Viral | Bacterial / Allergic |
|---|---|
| Watery discharge | Bacterial: thick, purulent |
| Burning, gritty feel | Allergic: intense itching |
| Often one eye first | Both eyes from the start (allergic) |
| Often with cold or sore throat | Bacterial: isolated red eye |
| Preauricular node often enlarged | Usually normal |
| Artificial tears, hygiene, no antibiotics | Antibiotic drops (bacterial); antihistamine drops (allergic) |
How we tell them apart in clinic
We examine the conjunctiva under a cobalt blue light with fluorescein to rule out a corneal abrasion or herpes simplex keratitis, both of which look similar to ordinary pink eye but need completely different treatment. We check visual acuity, pupillary response, and the preauricular lymph node, which is often enlarged in viral disease and normal in bacterial. If there is photophobia, pain beyond mild irritation, reduced vision, or a ciliary flush, we refer same day for ophthalmology review to exclude keratitis, iritis or acute angle-closure glaucoma. For associated sinus or respiratory symptoms, see our sinus infection page.
Treatment: right drops for the right cause
Viral conjunctivitis needs cold compresses, preservative-free artificial tears, and strict hygiene. Antibiotic drops do not shorten it. Bacterial conjunctivitis responds to a 5 to 7 day course of a topical antibiotic such as chloramphenicol, moxifloxacin or tobramycin; most resolve within days. Allergic conjunctivitis is treated with an antihistamine/mast-cell stabilizer drop such as olopatadine or ketotifen, plus identification and avoidance of the trigger. Contact lens wearers with red eye should stop lenses immediately and never be treated empirically for simple conjunctivitis, because Pseudomonas keratitis is a sight-threatening possibility that needs same-day specialist review. Patients with systemic allergy symptoms often benefit from oral antihistamines as well.
When to see a doctor
Book an appointment if the discharge is thick and purulent, if both eyes are involved and there is intense itch, or if a viral case has not started to improve after a week. Seek urgent care the same day for any eye pain beyond mild irritation, sensitivity to light, blurred vision, a white spot on the cornea, contact lens wear with red eye, or a history of eye surgery or herpes infection. These are red flags for keratitis, iritis or corneal ulcer and need slit-lamp examination. A newborn with red eye in the first month of life always warrants immediate review, regardless of appearance.
Red flag: If red-flag symptoms appear, do not wait. Book same-day or present to the nearest emergency department as described above.
Prevention and stopping household spread
Viral conjunctivitis spreads through hand-to-eye contact and shared towels or pillowcases for up to two weeks. Wash hands frequently, do not share face towels, change pillowcases daily while symptomatic, and discard eye makeup used during the infection. Children can return to school once discharge is controlled, per the American Academy of Pediatrics, which no longer requires exclusion for uncomplicated cases. For allergic forms, the most effective prevention is identifying the trigger, which often means dust mite control at home and a daily antihistamine during the pollen season. Avoid rubbing, which releases histamine and worsens the itch.
Summary
The single biggest reason pink eye gets mistreated is that viral and bacterial look similar to an untrained observer but respond to completely different things. A short clinic visit sorts it out, protects your cornea, and stops household spread. “If the eye hurts or the vision changes, it is not simple conjunctivitis until proven otherwise,” is how Dr. Pitsuwan frames the one rule worth remembering. Doctor Bangkok offers same-day review from our Asoke clinic or our 24/7 service.
Frequently asked questions
How long is pink eye contagious?
Viral conjunctivitis is contagious for as long as the eye is red and watering, usually 10 to 14 days. Bacterial conjunctivitis is non-contagious 24 hours after starting antibiotic drops.
Can I use leftover antibiotic eye drops?
No. Most pink eye is not bacterial, so you risk treating the wrong cause, preservative reactions, and resistance. Get a brief review first.
Is pink eye dangerous?
Ordinary conjunctivitis is not sight-threatening. The mimics that matter are keratitis, iritis, corneal ulcer, and angle-closure glaucoma, which cause pain and vision change and need same-day ophthalmology review.
Can I wear contact lenses with pink eye?
No. Stop lenses immediately, discard the current pair and case, and do not resume until cleared. Contact lens wearers with red eye need a slit-lamp examination to rule out microbial keratitis.
Is it pink eye or allergy?
Intense itching in both eyes, clear watering, and associated sneezing or runny nose strongly suggest allergy. Thick yellow discharge in one eye with minimal itch suggests bacterial.
Do children need to stay home from school with pink eye?
The American Academy of Pediatrics no longer recommends routine exclusion for uncomplicated conjunctivitis. Good hand hygiene and not sharing towels are what matter most.
Sources
- American Academy of Ophthalmology. Conjunctivitis Preferred Practice Pattern, 2023.
- American Academy of Pediatrics. Red Book: Conjunctivitis guidance.
Pink eye, conjunctivitis, viral conjunctivitis, adenoviral conjunctivitis, bacterial conjunctivitis, allergic conjunctivitis, keratoconjunctivitis, purulent discharge, preauricular lymphadenopathy, slit lamp, fluorescein, corneal abrasion, keratitis, microbial keratitis, Pseudomonas, iritis, angle-closure glaucoma, chloramphenicol, moxifloxacin, tobramycin, olopatadine, ketotifen, mast cell stabilizer, artificial tears, contact lens, AAO preferred practice pattern, AAP Red Book, Dr. Ponlawat Pitsuwan, Doctor Bangkok.