Conjunctivitis management in the community

Conjunctivities & Causes:

Conjunctivitis is an inflammation of the conjunctiva, commonly caused by either an allergic reaction or an infection (bacterial or viral). It presents with ocular redness, irritation, itching and discharge, with degrees varying according to the cause. Conjunctivitis is often self-limiting, however viral conjunctivitis can be recurrent and persist for weeks (Rutter, 2017).

Allergic conjunctivitis is due to an IgE mediated response to an allergen (pollen) – mast cells degranulates in response to an allergen and release inflammatory mediators such as histamine. This stimulates H1 and H2 receptors leading to ocular itching and swelling of the eye lid and conjunctiva (NICE, 2020).

Viral conjunctivitis is often caused by adenovirus whereas bacterial conjunctivitis has varying causes depending on age. In adults staphylococcus aureus accounts for around 50% of cases, in children Haemophilus, Streptococcus and Moraxella are equally likely to be the cause (NICE, 2021).

Clinical features:

Theses three causes of conjunctivitis all present with redness, discharge and discomfort however there are further differences, allowing for the correct diagnosis and treatment (Rutter, 2017).

Red flags associated with cold sores require referal to a doctor and consist of the following:

• Changes in vision
• Marked eye pain, headache or photophobia
• Inability to open the eye or keep it open.
• Indication of trauma or possible foreign body.
• Copious rapidly progressive discharge
• Presence of vesicular lesions (may indicate herpes simplex)
• Soft contact lens use with corneal symptoms (such as photophobia and watering)

Differential diagnosis (questions to ask the patient):

The following provides a non-exhaustive list of questions that should be asked to patients which present with suspected conjunctivitis.

1. Is the redness in the eye generalised?
   • Yes = Ask further questions – assess level of pain in the eye
   • No = Refer for further investigation, could be due to sinister pathology.
2. Are there any changes in vision?
   • Yes = Refer for further investigation, could be due to sinister pathology
   • No = Ask further questions
3. Are there signs of photophobia?
   • Yes = Refer for further investigation, sinister eye pathology suspected
   • No = Ask further questions
4. How is the pain?
   • Discomfort; gritty or itchy? = Ask more questions
   • True pain = Refer
   • No pain but sudden onset ­= Subconjunctival haemorrhage
5. Assess the discharge:
   • Purulent = Bacterial conjunctivitis
   • Watery = Ask further questions
6. Does the watery discharge have seasonal variance?
   • Yes = Treat and advice for allergic conjunctivitis
   • No = Could be viral conjunctivitis – symptoms such as cold or cough may be present.

Treatments:

Treatment for Bacterial Conjunctivitis

Chloramphenicol 0.5% w/v eye drops (Prescription Only Medicine)

• Mechanism: Chloramphenicol is a broad-spectrum antibiotic, with bacteriostatic activity. It irreversibly binds to bacterial ribosomes, inhibiting peptide bond formation and protein synthesis (DrugBank, 2021).
• Indication: For use in bacterial conjunctivitis.
• Side-effects: Local burning, stinging and irritation (NICE, 2021).
• Counselling:
  • Avoid in patients with a family history of dyscrasias.
  • Stop wearing soft contact lenses during treatment and until at least 48 hours after completing treatment (Rutter, 2017).
• Evidence: Systemic review by Sheikh et al concluded that the use of chloramphenicol sped up the resolution of symptoms of bacterial conjunctivitis at a faster rate in comparison to placebo (Sheikh A, 2012).

 Propamidine isetionate 0.1% w/v eye drops (Pharmacy Only)

• Mechanism: Exerts anti-bacterial activity against antibiotic-resistant staphylococci, pyogenic cocci and some gram-negative bacilli, exact mechanism not fully understood (EMC, 2020).
• Indication: Used topically for the treatment of minor eye infections such as conjunctivitis and blepharitis.
• Side-effects: Blurred vision, hypersensitivity may also occur (EMC, 2020).
• Counselling:
  • Avoid in pregnancy and during breastfeeding, unless essential
  • Stop wearing soft contact lenses during treatment and until at least 48 hours after completing treatment (Rutter, 2017).

Treatment for Allergic Conjunctivitis

Sodium cromoglicate 2% w/v eyedrops (Prescription Only Medicine)

• Mechanism: Mast cell stabilizer, preventing the release of histamine in response to allergens. This prevents the development of symptoms of allergic conjunctivitis (DrugBank, 2021).
• Indication: For the prophylaxis and symptomatic treatment of acute allergic conjunctivitis, chronic allergic conjunctivitis and vernal keratoconjunctivitis.
• Side-effects: Local irritation, blurred vision (BNF , 2021).
• Counselling:
  • The eyedrops may cause transient blurred vision, wait until this clears before driving or using tools or machines.
  • Stop wearing soft contact lenses during treatment and until at least 48 hours after completing treatment (Rutter, 2017).
• Evidence: Ocular symptoms of allergic conjunctivitis were controlled for individuals taking it regularly and those taking it when required, quality of life was better for patients taking sodium cromoglicate 4 times a day. Additional benefit from using it regularly and throughout the allergy season (Elizabeth F. Juniper, 1994).

Lodoxamide 0.1% w/v eyedrops (Prescription Only Medicine)

• Mechanism: Mast cell stabilizer, preventing the release of histamine in response to allergens. This prevents the development of symptoms of allergic conjunctivitis (DrugBank, 2021).
• Indication: Indicated in the treatment of non-infectious allergic conjunctivitis.
• Side-effects:
  • Headache, dizziness, and nausea.
  • Eye discomfort – irritation, itching or dryness. Blurred vision (Rutter, 2017).
• Counselling: Do not wear soft contact lenses while using this medicine.
• Evidence: In a double-blind, randomized study of the efficacy of lodoxamide versus placebo, lodoxamide was shown to be effective in reducing the levels inflammatory mediator tryptase and recruitment of inflammatory cells (Stefano Bonini, 1997). Lodoxamide was shown to be more effective than sodium cromoglicate in improving the symptoms of allergic eye disease (G. T. Fahy, 1992).

Otrivine Antistin (Xylometazoline 0.05% w/v Antazoline 0.5% w/v) Eye drops (Pharmacy Only)

• Mechanism:
  • Xylometazoline - Acts on α-adrenergic receptors. Activation leads to vasoconstriction, reducing eye redness (EMC, 2021).
  • Antazoline - Antagonizes histamine-1 receptors, preventing histamine from binding and causing symptoms such as itching (EMC, 2021).
• Indication: For the temporary relief of redness and itching of the eye due to seasonal and perennial allergies such as hay fever or house dust allergy.
• Side-effects:
  • Nosebleeds, this is uncommon.
  • Eye discomfort; stinging, redness, blurred vision
  • Allergic reactions; rash, swelling, itching of the eye area, eye irritation (EMC, 2021).
• Counselling:
  • Avoid if patient has glaucoma.
  • Some patient may experience blurred vision after using the eye drops, do not drive or use heavy machinery if this occurs.
  • Avoid use in patients taking monoamine oxidase inhibitors.
  • Stop wearing soft contact lenses during treatment and until at least 48 hours after completing treatment (Rutter, 2017).
• Evidence: Trials of Otrivine Antistin vs placebo showed that Otrivine produces a small but significant sympathomimetic effect when used as an eyedrop, however this effect too small to impose a risk to the patient. This means that Otrivine is useful as a symptomatic treatment for allergic conjunctivitis (D. R. Trew, 1989).

Naphazoline 0.01% w/v eyedrops (Pharmacy Only)

• Mechanism: Acts on α-adrenergic receptors. Activation leads to vasoconstriction, reducing eye redness (EMC, 2021).
• Indication: For temporary relief of redness of the eye due to minor eye irritations.
• Side-effects: Local irritation, headache, dizziness, nausea (EMC, 2021).
• Counselling:
  • Do not use while wearing contact lenses.
  • Do not use while taking monoamine oxidase inhibitors.
  • Avoid if patient has glaucoma.
  • Some patient may experience blurred vision after using the eye drops, do not drive or use heavy machinery if this occurs (EMC, 2021).
• Evidence: In a small trial of ocular decongestants, naphazoline eyedrops (0.02%) was shown to be significantly more vasoconstrictive than the other non-prescription decongestants. It also demonstrated a quicker onset of action, providing relief of symptoms quicker than other preparations (M. B. Abelson, 1980).

Viral conjunctivitis

Viral conjunctivitis has no specific OTC treatment – instruct patient to be vigilant of their hygiene as the condition can be highly contagious.

Self care advice for patients:

• Bathe eyelids in lukewarm water to help remove discharge.
• Use tissues to wipe eyes and throw away immediately.
• Avoid wearing contact lenses until symptoms have cleared.
• Wash hands regularly and avoid sharing towels or pillows.

References:

NF . (2021). SODIUM CROMOGLICATE | Drug | BNF content published by NICE. Retrieved from Bnf.nice.org.uk: https://bnf.nice.org.uk/drug/sodium-cromoglicate.html

297. R. Trew, L. A. (1989). Otrivine-Antistin-Pupil, Corneal and Conjunctival. Eye, 294-297.

Drugbank. (2021). Acrivastine: Uses, Interactions, Mechanism of Action | DrugBank Online. Retrieved from Go.drugbank.com: https://go.drugbank.com/drugs/DB09488

DrugBank. (2021). Chloramphenicol: Uses, Interactions, Mechanism of Action | DrugBank Online. Retrieved from Go.drugbank.com: https://go.drugbank.com/drugs/DB00446

DrugBank. (2021). Cromoglicic acid: Uses, Interactions, Mechanism of Action | DrugBank Online. Retrieved from Go.drugbank.com: https://go.drugbank.com/drugs/DB01003

Elizabeth F. Juniper, G. H. (1994). Sodium cromoglycate eye drops: Regular versus “as needed” use in the treatment of seasonal allergic conjunctivitis. The Journal of Allergy and Clinical Immunology, 36-43.

EMC. (2020, 03 12). Brolene Eye Drops - Summary of Product Characteristics (SmPC) - (emc). Retrieved from Medicines.org.uk: https://www.medicines.org.uk/emc/product/6742/smpc#PHARMACODYNAMIC_PROPS

EMC. (2021, 03 03). Optrex Bloodshot Eye Drops - Summary of Product Characteristics (SmPC) - (emc). Retrieved from Medicines.org.uk: https://www.medicines.org.uk/emc/product/5640/smpc

EMC. (2021, 06 01). Otrivine Antistin Eye Drops - Summary of Product Characteristics (SmPC) - (emc). Retrieved from Medicines.org.uk: https://www.medicines.org.uk/emc/product/6294

858. B. Abelson, G. K. (1980). Effects of ocular decongestants. Archives of opthalmology, 856-858.

NICE. (2020, 10). Causes | Background information | Conjunctivitis - allergic | CKS | NICE. Retrieved from Cks.nice.org.uk: https://cks.nice.org.uk/topics/conjunctivitis-allergic/background-information/causes/

NICE. (2021, 05). Causes | Background information | Conjunctivitis - infective | CKS | NICE. Retrieved from Cks.nice.org.uk: Causes | Background information | Conjunctivitis - infective | CKS | NICE

NICE. (2021, 05). Topical chloramphenicol | Prescribing information | Conjunctivitis - infective | CKS | NICE. Retrieved from Cks.nice.org.uk: https://cks.nice.org.uk/topics/conjunctivitis-infective/prescribing-information/topical-chloramphenicol/

Rutter, P. (2017). Opthalmology. In P. Rutter, Community Pharmacy symptoms, diagnosis and Treatment (pp. 55-63). Elsevier.

Sheikh A, H. B. (2012, 2012). Antibiotic versus placebo for acute bacterial conjunctivits (Review). Cochrane Database of Systemic Reviews . WILEY.

Stefano Bonini, M. S. (1997). Efficacy of Lodoxamide Eye Drops on Mast Cells and Eosinophils after Allergen Challenge in Allergic Conjunctivitis. Opthalmology, 731-894.