• Infectious or non-infectious Inflammation of the conjunctiva of one or both eyes
    • The conjunctiva is the translucent covering of the sclera (white area) of the eye (bulbar area) and the undersurface of the eyelids (palpebral area)
  • Infectious causes
    • Bacterial:
      • Children: influenzae, S. pneumoniae, S. aureus
      • Adults: aureus, coagulase-negative Staphylococcus organisms, H. influenzae, S. pneumoniae
    • Viral – adenovirus (most common), herpes simplex virus, others
  • Non-infectious
    • Allergic – IgE-mediated reaction triggered by seasonal or perennial allergens
    • Others – dry eye, contact lenses, chemical exposure, reaction to ophthalmic medications, trauma, etc.
  • Common complaint – infectious conjunctivitis accounts for 30 to 40% of eye-related medical visits
  • Risk factors for infectious conjunctivitis
    • Exposure to someone infected with active viral or bacterial conjunctivitis
    • Poor contact lens hygiene
    • Contaminated cosmetics
    • Chronic dry eye or blepharitis
    • Immunosuppression
  • Self-limited condition with or without treatment – complications very rare
  • For more information on conjunctivitis, go to:
  • Itching, redness and discharge primary signs and symptoms





Initial Eye Involvement






Purulent or

Usually unilateral but can present bilaterally






Unilateral or bilateral




 _ Generalized  


Serous or mucoid


*Mucoid – mucus discharge (viscous, sticky, clear, white or yellow); mucopurulent – consisting of mucus and pus; purulent – discharge of pus (thick, green - yellow); serous – clear thin watery discharge

  • Others: foreign body sensation, scratching or burning
  • Uncharacteristic signs and symptoms – consider alternate diagnosis and/or refer
    • Eye pain
    • Blurred vision
    • Photophobia
    • Coloured halos
  • Higher likelihood of bacterial conjunctivitis if
    • Gluey eyes in morning
    • Mucopurulent discharge
    • Age < 6 years
    • Lack of itching or burning sensation
    • Presentation in winter (children)
    • No history of conjunctivitis (adults)
  • Higher likelihood of viral conjunctivitis if:
    • Adult
    • Presentation in summer
    • Associated with upper respiratory infection
  • Higher likelihood of allergic conjunctivitis
    • History of recurring conjunctivitis
    • History of atopy
    • Associated with allergic rhinitis
    • Itchiness prominent feature
    • Follows a seasonal pattern

The following conditions may present with signs and symptoms similar to uncomplicated bacterial, viral or allergic conjunctivitis and must be ruled out before proceeding to treatment:

  • Dry eye syndrome – red eye caused by decreased tear production and/or increased moisture loss; gritty, irritated eyes with intermittent excessive tearing and blurred vision; chronic condition
  • Disease-associated: Sjogren’s, rheumatoid arthritis, thyroid disorder
  • Drug-induced: anticholinergics, beta-blockers, oral contraceptives, ophthalmic products
  • Adverse effect of an ophthalmic product
  • Blepharitis – red eye associated with inflammation of eyelids, crusted eyelashes, scant watery discharge; slow onset, chronic condition, may be associated with rosacea (http://www.skinsight.com/adult/blepharitis.htm)
  • Infectious keratitis – inflammation of the cornea caused by bacteria, viruses or fungi, can progress to corneal ulcers; may be rapid onset, loss of visual acuity, photophobia, severe foreign body sensation (cannot keep eye open), may be visible opacities in cornea. Contact lens wearers are at higher risk (http://www.medicinenet.com/image-collection/corneal_ulcer_picture/picture.htm)
  • Iritis / uveitis - Inflammation of the anterior uveal tract is called iritis or anterior uveitis; red ring around iris (ciliary flush); different sized pupils: no foreign body feeling, usually no discharge. (http://www.iritis.org/)
  • Corneal abrasion from foreign body – history of trauma to eye
  • Subconjunctival hemorrhage – defined areas of redness in the sclera (white of the eye) caused by hemorrhaging from the blood vessels under the conjunctiva: asymptomatic; benign, resolves in 1 to 2 weeks (http://patient.info/health/subconjunctival-haemorrhage-leaflet)
  • Angle-closure glaucoma – may present with conjunctival redness. Differentiating symptoms may include decreased vision, halos around lights, severe eye pain, headache, nausea and vomiting. Cornea may appear hazy. (http://www.emedicinehealth.com/slideshow_eye_diseases/article_em.htm)

Patients with the following signs and symptoms may have more serious or complicated conditions and should be referred (doctor, nurse practitioner or optometrist):

  • Decrease in visual acuity - iritis, keratitis, corneal ulcer, acute glaucoma
  • Severe photophobia - iritis, keratitis, corneal ulcer, acute glaucoma
  • Severe foreign body sensation that prevents the patient from keeping eye open
  • Moderate to severe pain - iritis, keratitis, corneal ulcer, acute glaucoma
  • Rash +/- vesicles on eyelids, around eyes – possible herpes simplex or zoster
  • Irregular pupil(s) – fixed, larger or smaller – iritis, glaucoma
  • Ciliary flush especially if unilateral – iritis, glaucoma
  • Severe headache with nausea – glaucoma
  • Hyper-purulent discharge (copious amounts of thick yellow-green pus) with very rapid onset – gonococcal conjunctivitis
  • Visible corneal haze or opacities – keratitis, iritis, glaucoma
  • Focal rather than diffuse redness
  • Contact lens wearer – higher risk of infection, corneal ulceration

1) Non-pharmacologic

  • Avoid contact lens use until symptoms have resolved
  • Discard any eye drop bottles used during infection
  • No-tears baby shampoo (weak solution with warm water) can be used to cleanse crusts from eyelashes
A) Bacterial
  • Warm compresses to unstick eyelids in morning
  • Irrigate with sterile saline or eye wash to remove secretions and provide relief
B) Viral
  • Cold compresses to relieve irritation, redness
C) Allergic
  • Allergen avoidance if possible
  • Avoid rubbing eyes
  • Sunglasses reduce exposure outdoors
  • Cold compresses over eye to relieve pruritus, swelling

2) Pharmacologic – OTC options

Lubricating drops or ointments for all types

A) Acute Bacterial
  • Polymyxin B-gramicidin eye drops, 4-6 times per day for 7-10 days
B) Viral
  • Antihistamines / decongestant eye drops may provide symptom relief
C) Allergic
  • Antihistamines / decongestant eye drops
  • Appropriate for short-term use (<2 weeks)
  • Mast cell stabilizer drops – not for acute symptoms
  • Systemic antihistamines useful, but less effective than topical
D) Adverse effects
  • Minor (all) - stinging on instillation
  • Serious (decongestants) - pupil dilation, angle-closure glaucoma in predisposed persons, e.g., elderly Caucasian or Asian females who are significantly hyperopic; positive family history. Overuse can cause rebound redness

3) Pharmacologic treatment – prescription options:

A) Acute bacterial

  • For most adults, topical antibiotics are not necessary – majority are viral infections
  • For children, antibiotic treatment reduces the duration of symptoms, decreases transmissibility of the infection and allows for a quicker return to daycare or school
  • Choice of antibiotic is empiric; no difference in comparative efficacy; choose least expensive, most convenient product
  • Ointment preferred for children; excessive tearing; or if patient unable to administer eye drops

First line:

  • Erythromycin 0.5% ophthalmic ointment
  • One-half inch (1.25 cm) QID for 5 to 7 days
  • Trimethoprim-polymyxin B 0.1%-10,000 units/mL ophthalmic drops
  • 1–2 drops q3h x 7 days
  • Tobramycin 0.3% ophthalmic drops or ointment (Children > 1 year)
  • Drops: 1–2 drops q4H, then taper
  • Ointment: 1.25 cm BID to TID
  • Should not be used for longer than 7 days due to risk of ocular toxicity

Second line: Out of scope for minor ailment prescribing

  • Fluoroquinolone ophthalmic products – reserved for contact lens wearers, more severe cases due to concerns about increasing resistance
  • Corticosteroids generally should be avoided due to potential for complications

Adverse Effects:

  • Transient stinging when first instilled
  • Blurred vision (for up to 20 minutes) with ointment use
  • Long term use - corneal epithelial toxicity, allergy and bacterial resistance
B) Viral – no Rx products recommended for uncomplicated conjunctivitis

C) Allergic
  • First line – dual action antihistamine/mast cell stabilizer
    • Ketotifen 0.01%, 0.035% (Children ≥ 3 years old
      • 1 drop < 3 times daily
    • Olopatadine 0.1%, 0.2%
      • 0.1%: 1-2 drops twice daily (Children ≥ 3 years old)
      • 0.2%: 1-2 drops once daily (Children ≥ 12 years old)
    • Fast onset of action, two weeks to reach maximum effect
  • Second line – mast cell stabilizers
    • Nedocromil 2%
    • 1-2 drops twice daily, approved for use in patients ≥ 3 years old
    • Lodoxamide 0.1%
    • 1-2 drops < 4 times daily, approved for use in patients ≥ 4 years old
    • Slow onset: 5 to 14 days; option for prophylaxis for seasonal allergies – begin therapy 2 to 4 weeks before allergen season
    • Adverse effects – well tolerated, < 1% of patients report adverse effects.

4) Pregnancy

  • Preferred therapy: non-pharmacologic measures, artificial tears
  • Second line: Lack of data on use of pharmacologic agents during pregnancy
    • Antihistamines not expected to cause toxicity
    • Short-term use of decongestants (avoid in 1st trimester)
    • Mast cell stabilizers considered unlikely to be harmful
    • Antibiotics:
      • Polymyxin B/gramicidin, erythromycin, tobramycin low risk
      • Trimethoprim possibly harmful (based on oral administration data)

5) Lactation

  • All recommended products are rated as likely compatible with breastfeeding

General Advice

  • Self-limiting condition
  • Bacterial and viral infections are very contagious especially for first 48 to 72 hours
    • Avoid contact with others for 24 to 48 hours after starting treatment
    • Wash hands frequently with soap and water; don’t share personal items
    • Topical antibiotics reduce possibility of bacterial infection transmission after 24 hours; no effect on viral transmission
  • Use of warm or cold compresses, lubricating drops and ointments to relieve symptoms
  • How to instill drops or ointment; how to use with other ophthalmic preparations
  • When to expect symptoms to resolve
    • Bacterial: expect improvement in 1-2 days with treatment
    • Viral: gradually resolves over 1-3 weeks
    • Allergic: resolves when no longer exposed to allergen
    • If no improvement or symptoms worsen, contact a healthcare provider
  • Possible adverse effects
    • Transient stinging when drops instilled - continue medication
    • Contact dermatitis, hypersensitivity reaction (uncommon) - stop medication, contact healthcare provider if severe or symptoms persist
  • Follow-up with patient after providing treatment; ask about symptoms, adverse effects
    • Bacterial – 2 days
    • Viral – 1 week
    • Allergic – 3 days
    • If no improvement, worsening symptoms, refer to optometrist, nurse practitioner or doctor

Detailed information on contraindications, cautions, adverse effects and interactions is available in individual drug monographs in the RxTx - CPS from CPhA, RxTx (internet), Lexi-Comp, AHFS, www.drugs.com or other reliable drug monograph references. For comprehensive drug comparisons, see RxFiles charts (www.rxfiles.ca). This information should be routinely consulted before prescribing.




Erythromycin 0.5% ophthalmic ointment*

One-half inch (1.25cm) QID x 5-7 days

Trimethoprim-polymyxin B 0.1% - 10,000 units/ml drops

1-2 drops q3h x 7 days

Tobramycin 0.3% ophthalmic drops or ointment

Drops: 1-2 drops q4h x 7 days Ointment: 1.25cm BID to TID x 7 days


Ketotifen 0.01% or 0.035%*

1 drop TID

Olopatadine 0.1 or 0.2%*

0.1%: 1-2 drops BID
0.2%: 1-2 drops OD

Nedocromil 2%*

1-2 drops BID

Lodoxamide 0.1%

1-2 drops QID




















*Not a listed benefit of the Saskatchewan Drug Plan.

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  2. Jackson WB. Red eye. In: RxTx CTC [Internet]. Canadian Pharmacists Association. Available from: http://www.e-therapeutics.ca. (by subscription). (Available in Saskatchewan through SHIRP (www.shirp.ca).
  3. Trobe, J.  Conjunctivitis.  In: UpToDate. Available at http://www.uptodate.com/contents/conjunctivitis. (by subscription).
  4. Ostrovski D. Infectious conjunctivitis. In: Dynamed. Available at https://dynamed.ebscohost.com/ (by subscription). 
  5. Allergic conjunctivitis. In: Dynamed. Available at https://dynamed.ebscohost.com/ (by subscription).
  6. Yeung, K.  Bacterial conjunctivitis.  In: Medscape.  Available at http://emedicine.medscape.com/article/1191730-overview.
  7. Pink eye (conjunctivitis). In: Mayo Clinic. www.mayoclinic.org. (free access)
  8. Azari AA, Barney NP. Conjunctivitis: a systematic review of diagnosis and treatment. JAMA 2013;310(16):1721-9.
  9. AAO Cornea/External Disease PPP Panel. Conjunctivitis. Available at http://www.aao.org/preferred-practice-pattern/conjunctivitis-ppp--2013.
  10. Cronau H,  Kankanala, R  Mauger T.  Diagnosis and Management of Red Eye in Primary Care. Am Fam Physician. 2010 Jan 15;81(2):137-144

No part of this work may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the copyright holder. For copyright permission requests, please contact druginfo@usask.ca.

Written by medSask
Posted Feb 2018; Updated October 2018