Conjunctivitis (allergic)
Consultation guide for UK community pharmacy: clinical features, referral criteria, time frame to resolution and management strategy.
Clinical features
- Both eyes usually affected; symptoms develop fairly quickly
- Eyes appear red/bloodshot and are itchy, gritty (possibly a burning sensation and watery discharge)
- Mild to moderate eyelid oedema (severe: periorbital oedema)
- Other symptoms: sneezing and rhinorrhoea
- Bacterial and viral conjunctivitis are discussed separately under the headings 'conjunctivitis (bacterial)' and 'conjunctivitis (viral)' [Bacterial may affect one eye first, then spread to the other; discharge is mucopurulent/purulent. Viral tends to be associated with a watery discharge and may have other symptoms of an upper respiratory tract infection]
Referral criteria
- General point: if complications affect vision (potentially resulting in a loss of vision), it is vital that such referrals are urgent/prompt and possibly to hospital rather than the GP
- Vision is affected (double or blurred vision, peripheral vision)
- Moderate-to-severe eye pain (not grittiness or a burning sensation)
- Irregularly shaped pupils, issues with dilation (unreactive/fixed pupils)
- Photophobia
- Marked redness of the whole eye or redness/signs of damage specifically around pupil (particularly in a contact lens wearer)
- Severe swelling of the eye/face
- Unsure if straightforward/uncomplicated (for example, if patient has an existing eye condition or recent injury or surgery in the last 6 months)
- Irritant conjunctivitis (acid or alkali burns or exposure to irritating substance)
- Neonatal conjunctivitis
- Primary angle closure glaucoma (eye pain; headache, nausea and vomiting caused by pain, red eye, impaired vision, lights seen with surrounding halos, pupil dilation impaired)
- Uveitis (eye pain, impaired/blurred vision, watering, photophobia, floaters, unreactive or irregular-shaped pupil, possible red eye)
- Keratitis or corneal ulcer (unilateral, painful, photophobia, contact lens wearer). Be mindful that contact lens wearers are at risk of developing giant papillary conjunctivitis (GPC) which can present with conjunctivitis-type symptoms but requires referral to an optometrist for further investigation
- Scleritis (pain, headache, association with other inflammatory diseases, vision reduced)
- Herpes simplex infection
- Adverse reaction to medicine (or excipient of prescribed eye product)
Time frame to resolution
- Depends on the allergen and level of exposure; symptoms can resolve a short time after exposure ceases
Management strategy
Non-pharmacological advice
- Enquire about personal/family history of atopy and establish when symptoms occur to help determine the allergen and hence the most appropriate non pharmacological advice. Example allergens include house dust mites (worse on waking, all year round); animal dander (may be all-year or occasional); tree pollens (early to late spring); grass pollens (late spring to early summer); weed pollens (early spring to early autumn) and work-related (symptoms tend to improve when away from work). Avoid the causative allergen, if possible
- Non pharmacological advice on pollen, house dust mite, animal, occupational - provided under rhinitis
- Contact lenses or cosmetics: may require brand change
- Cool compress may provide relief and best not to rub eyes (mechanical mast cell degranulation)
Pharmacological advice
- Mast cell stabilisers (sodium cromoglicate eye drops) or ocular antihistamines
- See also 'rhinitis' about oral antihistamines and nasal corticosteroids, particularly if other symptoms present
- Explain how to use; many eye drop preparations need to be discarded 28 days after opening
- Contact lens wearer (may affect product choice due to problems with preservatives like benzalkonium chloride)
- Check product is actually licensed for the condition. For example, some OTC eye drops are only licensed for hay fever, rather than the more general and inclusive term 'allergic conjunctivitis'
- Pregnancy: provide non pharmacological advice but OTC products for allergic conjunctivitis are not usually licensed, necessitating a referral