Conjunctivitis – an irritating condition

Case scenario

Kon is a student and resident of a shared university dormitory who has come into your pharmacy complaining of red and ‘icky’ eyes. He mentions it started yesterday and that it was a little difficult to open his eyes this morning. He describes some discomfort but not pain. You rule out any red flag symptoms such as photophobia or vision changes and ensure he does not have symptoms suggestive of more sinister bacterial infection. Kon is otherwise well and does not use corrective eyewear. He tells you that one of his friends had red eyes last week.

Learning objectives After reading this article, pharmacists should be able to: Describe the signs and symptoms of conjunctivitis Describe when patients with ocular symptoms should be referred to a medical practitioner Explain treatment options for conjunctivitis. Competency (2016) Standards addressed: 1.1, 1.3, 1.4, 1.5, 3.1, 3.2, 3.5. Accreditation expiry: 31/01/2027 Accreditation number: CAP2402OTCLB

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Introduction 

Conjunctivitis is a common ophthalmic condition characterised by inflammation of the conjunctiva.^1,2 Causes of conjunctivitis can be either infective (e.g. bacterial, viral) or non-infective (e.g. allergic, chemical irritation). Although most cases are self-limiting and the condition does not typically endanger vision, treatment and/or further referral may be appropriate in some cases.^1,3–6 Correct diagnosis is important for effective management and to reduce inappropriate antibiotic use.¹ Depending on the underlying cause, management may involve the use of antimicrobials, antihistamines or lubricating topical preparations. Non-pharmacological strategies may include practices such as eyelid bathing, cold compresses, allergen avoidance and good hygiene practices.^1,3–6

Pharmacists may be significantly involved in the management of conjunctivitis, including the diagnosis, treatment, provision of advice, follow-up and/or referral.

Background 

The conjunctiva is a thin, semi-transparent membrane which covers the anterior part of the sclera (white part of the eye) and the inside of the eyelids.⁷ Inflammation of the conjunctiva can lead to dilation of conjunctival blood vessels, which causes redness on the whites of the eye and inside the eyelid. Eye discharge is also a common feature.⁷ Conjunctivitis is typically acute, associated with rapid onset and lasting 4 weeks or less in duration. It may also be chronic, lasting longer than 4 weeks.⁷

Common causes of acute conjunctivitis are described in Table 1 and discussed in this article. 

Rarely, hyperacute cases of conjunctivitis may occur (typically caused by Neisseria gonorrhoeae), associated with copious purulent discharge, severe conjunctival symptoms, abrupt onset and rapid progression. These cases can quickly become sight-threatening.¹

Infective causes 

Bacterial conjunctivitis 

Bacterial conjunctivitis often presents with unilateral symptoms of rapid onset that frequently become bilateral.^1,3 It is commonly caused by Staphylococcus aureus, Streptococcus pneumoniae or Haemophilus influenzae and is the most common infective conjunctivitis in children, with the elderly also having an increased risk.^1,3 Symptoms include red eye, purulent discharge, discomfort (may be described as grittiness) and adherence of the eyelids (crusting). 

Predisposing factors can include^1,3,8:

• previous superficial trauma
• compromised tear production
• bacterial contamination of the conjunctiva
• contact lens wear (particularly with poor hygiene practices)
• diabetes
• immunocompromised status
• steroid treatment
• blepharitis.

Gonococcal conjunctivitis 

Gonococcal conjunctivitis is a severe, hyperacute form of conjunctivitis. This condition is caused by the bacteria Neisseria gonorrhoeae and presents with a rapid onset of copious, purulent discharge.^1,8 It is an ophthalmic medical emergency, as ulceration and perforation of the cornea may develop, and patients should be urgently referred if this is suspected.¹ Infection in children, including infants and neonates, may occur via mother to child, or may be a sign of sexual abuse.¹

Treatment with systemic antibiotics is required, as gonococcal ocular infections carry high risk of complications. In addition, an hourly saline lavage is suggested in neonates.^1,8 For further information on the management of gonococcal conjunctivitis, see Therapeutic Guidelines: Conjunctivitis.¹

Viral conjunctivitis

Viral conjunctivitis is the most common type of infectious conjunctivitis. It usually presents with unilateral symptoms that often become bilateral and is the most common infective conjunctivitis in adults (usually aged 20–40 years).^1,4 Symptoms may include red eye, watery or mucoid discharge, local irritation and systemic malaise.¹ It is mostly caused by the highly contagious pathogen adenovirus (65–90% of cases), and is often associated with an upper viral respiratory tract infection. Other predisposing factors include crowded conditions and poor hygiene.^1,2,4 

Less common causes (very rare) include enterovirus 70 (EV70), coxsackievirus A24 (CA24v) and SARS-CoV-2 coronavirus (COVID-19).⁴ Herpes simplex virus (HSV) and varicella zoster virus (VZV) can be a cause of viral conjunctivitis presentations as well. Prompt referral to an optometrist or medical practitioner is indicated in patients presenting with suspected herpetic conjunctivitis. See the Australian Pharmaceutical Formulary (APF) conjunctivitis non-prescription medicine guide for further information.

Non-infective causes 

Allergic conjunctivitis 

Allergic conjunctivitis is the result of a type I hypersensitivity reaction to an allergen, creating a localised response.¹ Symptoms are usually bilateral and include redness, itch and watery discharge. It is largely seasonal, caused by allergens such as grass or pollen and typically occurs in spring or autumn. Some cases may be perennial (non-seasonal specific) caused by allergens such as animal dander or dust mites.⁶ Predisposing factors include patients with an atopic disposition, personal or family history of allergies, and exposure to the allergen.⁶ There is often an association between allergic rhinitis and allergic conjunctivitis, with up to 71% of allergic rhinitis patients having conjunctival symptoms.⁵

What are the differential diagnoses? 

Differential diagnoses typically relate to the most prominent symptoms seen, and consideration of other possible causes.^3–6 For example, other causes of an acute red eye include angle-closure glaucoma, infective keratitis and anterior uveitis.³ Causes of ocular discharge include all forms of conjunctivitis, Acanthamoeba keratitis and herpes zoster.^3–6

Pharmacists are often limited in the extent of assessment in the primary health care setting. Assessment should cover any relevant medical, medicines and lifestyle history. This can include asking the patient about their symptoms (e.g. onset, duration, discharge), coexisting medical conditions and contact lens use. Possible signs or recent diagnosis of active herpes infection such as cold sores or shingles should also be considered in case the cause of conjunctivitis is herpetic.² See the APF conjunctivitis non-prescription medicine guide for a comprehensive list of considerations.⁷ In contrast, optometrist assessment may include additional investigations such as checking visual acuity and examining the eyeball under torch or slit lamp to rule out signs of corneal ulceration or sinister infection.²

When is referral required? 

Urgent (same day) referral to an optometrist, ophthalmologist or hospital is required in patients with red eye that is associated with a red flag sign or symptom, as this may suggest a severe or sight-threatening condition.^1,10

Red flag signs and symptoms include those such as^1,7,10–12:

• significant pain
• vision changes
• severe headache and nausea
• restricted eye movement
• severe foreign body sensation
• severe/copious purulent discharge
• corneal opacity or cloudiness
• photophobia
• suspected eye trauma
• signs or symptoms of herpetic gonococcal or chlamydial infection
• abnormal pupils or redness around the iris. 

Patients who wear contact lenses, have had recent eye surgery or are immunocompromised should also be referred urgently for further investigation.⁷

Signs of conjunctivitis in children under 2 years of age should be referred promptly to a medical practitioner or optometrist to exclude potentially serious causes which can threaten vision.⁷

For acute viral and bacterial conjunctivitis, if symptoms worsen, are recurring or persist beyond 7 days, advise the patient to seek further help.^3,7

See the APF conjunctivitis non-prescription medicine guide for further information.

Management 

Most cases of viral, bacterial and allergic conjunctivitis are self-limiting and resolve without treatment^1,3,6,12:

• Most cases of bacterial conjunctivitis resolve spontaneously within 1 week of presentation.
• Viral conjunctivitis often worsens for 3–5 days then gradually resolves within 1–2 weeks.
• Most cases of acute allergic conjunctivitis resolve spontaneously within a few hours once the allergen is no longer present. 

Non-pharmacological strategies (and pharmacological treatment where considered appropriate) can be used to help alleviate symptoms. Hygiene measures, as discussed below, are an important way to limit the spread of infectious conjunctivitis.

Non-pharmacological strategies 

Bacterial conjunctivitis 

As bacterial conjunctivitis is contagious, hygiene education is vital in informing patients how to reduce contamination risk (between eyes and among individuals).¹¹ Good hygiene practice includes washing hands often, avoiding hand-to-eye contact, and discarding used makeup, contact lens solution and disposable contact lenses.¹¹ Patients should also avoid sharing towels and using public swimming pools while infected.¹¹

Patients may bathe/cleanse the eyelids to remove discharge or ‘grit’ using sterile wipes, or cotton balls dipped in sterile saline, sterile water (or water that has been boiled, then cooled).¹¹

Viral conjunctivitis 

Self-care strategies, such as cool compresses several times per day, may help alleviate symptoms.^4,12 As viral conjunctivitis is highly contagious, with the period of contagion lasting up to 14 days from symptom onset, patients should be advised to practise good hygiene as discussed for bacterial conjunctivitis.^1,4

Allergic conjunctivitis 

Patients should be advised to avoid eye rubbing, as this can cause mechanical mast cell degranulation and worsening of the condition.⁶ Avoidance of allergens/triggers, if known, should be advised. Other self-care strategies include cold compresses for symptomatic relief and/or ocular lubricants such as saline drops or artificial tears.⁶

Pharmacological treatment options

Bacterial infections 

Antibiotic treatment may modestly improve the short-term outcome and cause the patient to become less contagious.³ Given many cases resolve within 7 days without treatment, it is important to weigh the potential benefits against risks such as antibiotic resistance and adverse effects.³ For example, treatment with a topical antibiotic may be appropriate if symptoms of infection are pronounced (e.g. purulent discharge) or if the infection occurs in a neonate or young infant (once properly assessed by an optometrist/medical practitioner).¹

Choice of topical antibiotics used in bacterial conjunctivitis included^1,13,14:

• chloramphenicol 0.5% eye drops (Pharmacist Only medicine – Schedule 3)
• chloramphenicol 1% eye ointment (Pharmacist Only medicine – Schedule 3), and framycetin 0.5% eye drops (Prescription Only medicine – Schedule 4).

if treatment fails to resolve symptoms within 48 hours, referal to the GP or optometrist is indicated.⁷

Viral infections

Antibiotics are not indicated in the treatment of viral conjunctivitis, and their use can lead to delay in diagnosis, increased bacteria resistance and potential adverse effects. Symptomatic management, such as use of cold compresses and lubricating eye drops, is recommended.¹ Along with self-care measures, symptomatic treatment may involve topical antihistamines to relieve severe itching and systemic analgesics for pain relief.^2,4,12 Where a combination of lubricating eye drops and ointment is used, eye drops should be used during the day and ointment used before bedtime.⁴ For examples of topical antihistamines, see allergic conjunctivitis below. 

Allergic conjunctivitis 

For the symptomatic management of allergic conjunctivitis, topical antihistamines with or without mast-cell stabilisers may be used in addition to ocular lubricants and cold compresses.^6,15 Topical antihistamines provide quick but short-term relief, while mast-cell stabilisers provide prophylactic cover.¹⁵ Mast-cell stabilisers may be used if symptoms are recurrent or persistent but can take several weeks of regular use to provide any prophylactic benefit.⁷ 

Some topical antihistamine preparations may be combined with a vasoconstricting medicine. Caution should be exercised when recommending these preparations, as chronic use of a vasoconstrictor can cause vasodilation upon discontinuation (rebound hyperaemia). Vasoconstrictors should be used for no longer than 5 days at a time.⁷

Examples of topical preparations available include:^15,20

• Topical antihistamines:
• • levocabastine 0.05% eye drops 
• Topical antihistamines (some mast-cell stabiliser action):
  • ketotifen 0.025% eye drops 
  • olopatadine 0.1% eye drops (Prescription Only medicine – Schedule 4) 
  • azelastine 0.05% eye drops
• Mast-cell stabilisers: 
  • cromoglycate 2% eye drops
  • lodoxamide 0.1% eye drops.

Other treatment options, when symptoms of allergy are not restricted to the eye, may include oral/intranasal antihistamines and intranasal corticosteroids.^7,10 Please refer to the APF allergic rhinitis non-prescription medicine guide and Essential CPE – Allergy and anaphylaxis for further information regarding assessment and treatment of allergic rhinitis.

Potential interactions and adverse effects 

Generally, very few interactions are reported with eye drops used in the treatment of conjunctivitis.^16–20 This is likely due to minimal systemic absorption with ocular use. 

Potential adverse effects from systemic absorption of eye drops can be dramatically reduced (up to two-thirds) using the correct eye drops instillation method.^16,18,22 Refer to the APF for further information on this method. 

Localised effects such as hypersensitivity and local irritation can occur with topical preparations. In addition, patients requiring treatment with eye drops or ointment should be advised that blurred vision may occur and that driving or performing skilled tasks should be avoided until this resolves. Eye ointments are typically used at night for this reason.²² 

Please refer to the relevant product information, Therapeutic Guidelines and the Australian Medicines Handbook for information on adverse effects for individual products.

Additional considerations for wearers of contact lenses 

Contact lens wear should be discontinued until conjunctivitis symptoms have resolved entirely, or as advised by an optometrist or medical practitioner.^3,4 

In addition, there is uncertainty about compatibility between some topical eye preparations and contact lens solutions. Advice should be sought from an optometrist and product information before contact lenses are used in conjunction with topical eye preparations.⁷

Knowledge to practice 

As conjunctivitis is a common condition, pharmacists can play a key role in diagnosing, advising and treating the patient, as appropriate. Pharmacists should be able to recognise red flag signs and symptoms that require referral to an optometrist or medical practitioner. Pharmacists can advise patients on the self-limiting nature of conjunctivitis and the expectations of resolution, and can provide management advice, including good hygiene practices, trigger avoidance for prevention, and what to do should resolution not occur.

Conclusion 

Conjunctivitis is a common eye condition that is often self-limiting but may require antimicrobial or symptomatic treatment and/or appropriate referral. Self-care measures play a vital role in alleviating symptoms and, in many cases, minimising spread.

Case scenario continued You advise Kon that he has likely contracted bacterial conjunctivitis, but you reassure him that this is often self-limiting and usually resolves without treatment. As he is living in a shared space, is experiencing marked purulent discharge, and has concerns over upcoming studies, you advise him to use a course of chloramphenicol eye drops. You discuss the importance of self-care measures such as eye cleansing and prevention strategies such as good hygiene practices. You discuss antibiotic use, frequency, duration and when to discard the bottle, and advise him to see an optometrist or his GP if his symptoms do not improve within 48 hours, or if red flag symptoms develop.

Key points

• Conjunctivitis is inflammation of the conjunctiva. It may be infective or non-infective in nature.
• Treatment of conjunctivitis includes self-care measures and use of topical eye preparations as appropriate.
•  Pharmacists can play a role in the diagnosis and management of conjunctivitis, including advising on self-care measures, providing medicines and medicines advice, and recommending referral, if appropriate.

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Further information

• Australian Pharmaceutical Formulary (APF) non-prescription medicine guide (Conjunctivitis): At: https://apf.psa.org.au
• Instructions for administration of eyedrops: At: https://apf.psa.org.au/dispensing-and-labelling/cautionary-advisory-labels/instructions-administration-different-dosage
• Therapeutic Guidelines: Conjunctivitis: At: https:/tgldcdp.tg.org.au/etgcomplete

References

1. Conjunctivitis [revised April 2019]. In: eTG complete. Melbourne: Therapeutic Guidelines; 2020.
2. Watson S, Carbrera-Aguas M, Khoo P. Common eye infections. Aust Prescr 2018;41:67–72. At: www.nps.org.au/assets/d1e1894daab433a1-9ed1066742d1-p67-Watson-et-al-v3.pdf
3. The College of Optometrists. Conjunctivitis (bacterial). 2023. At: www.college-optometrists.org/guidance/clinical-management-guidelines/conjunctivitis-bacterial-.html
4. The College of Optometrists. Conjunctivitis (viral, non-herpetic). 2022. At: www.college-optometrists.org/guidance/clinical-management-guidelines/conjunctivitis-viral-non-herpetic-.html
5. The College of Optometrists. Conjunctivitis (acute allergic). 2023. At: www.college-optometrists.org/guidance/clinical-management-guidelines/conjunctivitis-acute-allergic-.html
6. The College of Optometrists. Seasonal allergic conjunctivitis; perennial allergic conjunctivitis. 2023. At: www.college-optometrists.org/guidance/clinical-management-guidelines/seasonal-allergic-conjunctivitis.html
7. Sansom LN, ed. Australian pharmaceutical formulary and handbook. 2023. Conjunctivitis. At: https://apf.psa.org.au
8. Azari A, Arabi A. Conjunctivitis: A systematic review. J Ophthalmic Vis Res 2020;15(3):372–95.
9. The College of Optometrists. Conjunctivitis, chlamydial (adult incision conjunctivitis). 2018. At: www.college-optometrists.org/guidance/clinical-management-guidelines/conjunctivitis-chlamydial.html
10. Dermnet NZ. Allergic conjunctivitis. 2015. At: https://dermnetnz.org/topics/allergic-conjunctivitis/
11. Dermnet NZ. Bacterial conjunctivitis. 2015. At: https://dermnetnz.org/topics/bacterial-conjunctivitis/
12. Dermnet NZ. Viral conjunctivitis. 2015. At: https://dermnetnz.org/topics/viral-conjunctivitis/
13. Aspen Pharma. Chlorsig product information. 2021. At: https://www.emims.com.au/Australia/drug/info/Chlorsig/Chlorsig?type=full
14. Sanofi-aventis. Soframycin eye product information. 1994 [updated 2022 Jun 10]. At: https://www.emims.com.au/Australia/drug/info/Soframycin%20Eye/Soframycin%20Eye?type=brief
15. Randall K and Hawkins C. Antihistamines and allergy. Aust Prescr 2018;41:42–5.
16. Mylan. Eyezep product information. 2005 [updated 2021 Oct 27]. At: www.emims.com.au/Australia/drug/info/Eyezep/Eyezep?type=full
17. AFT. Cromo-Fresh product information. 2015. At: www.emims.com.au/Australia/patientmedicine/cmi/Cromo-Fresh?id=12443&type=CMI
18. Novartis. Patanol product information. 2002 [updated 2021 Jan 13]. At: www.emims.com.au/Australia/drug/info/Patanol/Patanol?type=full
19. Novartis. Zaditen eye drops product information. 2007 [updated 2021 Jan 28]. At: www.emims.com.au/Australia/drug/info/Zaditen/Zaditen?type=brief
20. Novartis. Lomide product information. 1997 [updated 2021 Jan 12]. At: www.medsafe.govt.nz/Profs/Datasheet/l/lomideeyedrops.pdf
21. Rossi S, ed. Australian medicines handbook. 2022. At: https://amhonline.amh.net.au
22. 22. Sansom LN, ed. Australian pharmaceutical formulary and handbook. 2023. Instructions for administration of different dosage forms; [2023 Jul 27]. At: https://apf.psa.org.au/dispensing-and-labelling/cautionary-advisory-labels/instructions-administration-different-dosage

Acknowledgement by PSA

Hana Numan was the original author of this article.

Our reviewer

BBioMedSC, BPharm, GradCertClinPharm Ophthalmology Clinical Pharmacist, Princess Alexandria Hospital, Brisbane.