Conjunctivitis

The term conjunctivitis refers to inflammation of the conjunctiva; associated corneal involvement gives rise to keratoconjunctivitis and eyelid involvement suggests blepharoconjunctivitis. Inflammation can be infective or non-infective in origin and can be further subdivided into acute or chronic conjunctivitis. It is a worldwide condition that can affect any age group with no gender, ethnic or social preponderance. Although it is generally a reasonably trivial problem, it can have a considerable impact on lost work time and very occasionally, can result in permanent or sight-threatening sequelae.¹

If you think that this is a conjunctival problem that is not conjunctivitis, go to our record on Conjunctival Problems where you will find out more about assessing the conjunctiva and where there are details on:

• Conjunctival trauma
• Degenerative conditions of the conjunctiva (pinguecula, pterygium, concretions, retention cysts)
• Other inflammatory conditions (mucus fishing syndrome, ligneous conjunctivitis)
• Blistering mucocutaneous diseases (cicatricial pemphigoid, Stevens-Johnson syndrome)
• Conjunctival lesions (pigmented, squamous tumours and other tumours)

Symptoms

• Red eye - usually generalised, often bilateral; go through list of differentials if localised.
• Pain - irritation and discomfort is the norm: severe pain suggests something more serious.
• Discharge - variable in nature, see below.
• Photophobia - suggests corneal involvement too.
• Visual acuity - should be no or minimal reduction. This may be related to tearing and discharge: consider differential diagnosis if there is any significant visual loss.

Signs

• Conjunctival injection - dilated conjunctival vessels.
• Conjunctival chemosis - oedema of the conjunctiva.
• Follicles or papillae - see below.
• Corneal involvement - more unusual for this to occur: look out for oedema, neovascularisation and epithelial erosions (small punctate areas of fluorescein uptake).

History

If the aetiology is not obvious after a general history is taken, specifically ask about contact lens wear, trauma (including chemical and ultraviolet exposure) and symptoms and signs potentially related to systemic disease.¹

Examination

• Wear gloves if suspecting adenoviral infection - this is incredibly contagious (and clean all equipment after use).
• Look for evidence of generalised malaise and tender preauricular lymph nodes.
• Check the visual acuity.
• External eye: assess for evidence of orbital cellulitis, blepharitis, herpetic rash or naso-lacrimal blockage.
• Conjunctiva: look at the pattern of congestion, discharge and for the presence of follicles or papillae.
  • Papillae - these are formed when the conjunctival inflammation is effectively limited by fibrous septa, so giving rise to the appearance of vascular bulges, generally found on the upper tarsal conjunctiva. They can coalesce to form giant (cobblestone) papillae.
  • Follicles - these are lymphoid collections and look like raised gelatinous pale bumps (like small grains of rice). They tend to be found on the lower tarsal conjunctiva and along the upper tarsal border.
• Cornea: is there evidence of corneal involvement? Staining is an essential part of the examination.
• Fundoscopy: if you are unsure about the diagnosis.

Investigations

Generally, the diagnosis is rapidly made following history and examination but further investigations are warranted (refer to specialist) in the following circumstances:²

• Severe purulent discharge
• Follicular conjunctivitis
• Neonatal conjunctivitis
• Unclear aetiology
• Non-response to conventional treatment

• Uveitis: marked pain, photophobia and possibly decreased visual acuity should ring alarm bells in a "conjunctivitis" not responding to conventional treatment, particularly in patients with previous episodes (they usually recognise their symptoms) or with systemic illnesses predisposing to uveitis.
• Glaucoma: look out for a reduced visual acuity, hazy cornea, fixed pupil and acute systemic malaise.
• Herpes zoster ophthalmicus: any tell-tale rash (or severe herpetic pain which can occur before the rash)? May be associated with conjunctivitis (see below).
• Keratitis: may be associated with conjunctivitis but can occur alone, often secondary to infection (be suspicious of this in contact lens wearers) - look for unilaterality, severe pain and photophobia.
• Scleritis / episcleritis: look for unilaterality, localised injection (episcleritis) or an intense, boring pain (scleritis).
• Foreign body: this may not be remembered by the patient (beach walk on a windy day, metal grinding using goggles without lateral protection, dusty attic spring clean). Evert the lids - you need to look out for follicles and papillae anyway. If you can't find anything but still strongly suspect this, double evert the lids after instilling topical anaesthetic or refer to the ophthalmology team.
• Trauma: may not always be remembered by patient and can be mechanical or chemical.

Conjunctivitis of different aetiologies can appear to present in a similar fashion so here are a few tips:³

If follicles are present

If papillae are present

• Viral conjunctivitis
• Allergic conjunctivitis
• Other less common types of conjunctivitis

To find out more about bacterial conjunctivitis, see our dedicated record which covers:

• Simple bacterial conjunctivitis
• Gonococcal conjunctivitis
• Chlamydial Conjunctivitis
• Ophthalmia neonatorum (which also has its own record)

Adenoviral conjunctivitis

• Essence - a highly infectious condition (incubation: 3-29 days, infectious for about 2 weeks⁴) that can range from mild to severe symptoms, transmitted via respiratory or ocular secretions. It can be further spread via contaminated objects (hands, towels, tonometer heads).²
• Risk factors¹ - exposure to infected individual, upper respiratory tract infection, recent ocular examination.
• Suggestive symptoms - itching, burning, watering, often become bilateral within days.
• Signs to look for - eyelid oedema, watery discharge, follicles, subconjunctival haemorrhages and pseudomembranes if severe, keratitis (see signs above), tender preauricular lymphadenopathy.
• Management - symptomatic: discontinue contact lens wear until 24 hours after symptoms have fully resolved, cool compresses, lubricants. Advise strict adherence to hygiene measures (hand washing, don't share towels, don't swim). Refer to ophthalmology if cornea becomes involved. In severe or recalcitrant cases, antihistamines and steroids may be used.^2,3
• Additional notes - advise patients that symptoms may last 2-3 weeks and may get worse before getting better: they should return if symptoms not beginning to improve by 1-2 weeks. Current advice is that individuals need not take time off work or school if they are not systemically unwell and that young children need not be excluded from nursery either unless there is an outbreak.⁵ However common sense should prevail and many establishments reasonably ask that children are kept at home until the symptoms have cleared.

Herpes simplex virus conjunctivitis

• Essence⁶ - usually caused by infection with HSV-1. This occurs equally in young / middle-aged males and females (contrast with herpes zoster: more commonly found in the elderly). Primary infection is often sub clinical (90% of cases); ocular infection occurs with reactivation of the virus (see risk factors below), which lies dormant in the trigeminal nerve. Neonatal infection is more commonly caused by HSV-2 and occurs during vaginal delivery.
• Risk factors^1,3 - primary HSV infection: exposure to infected individual. Secondary HSV infection: previous ocular HSV or cold sores, physical stress (acute viral or febrile illness, trauma, menstruation), psychological stress, environmental stress (e.g. UV light, cold wind).
• Suggestive symptoms - unilateral pain, burning, foreign body sensation. Vision may be blurred if there is corneal ulceration in the central visual axis.
• Signs to look for - conjunctival injection, watery discharge, follicles. Look for any concurrent herpetic skin vesicles along the lid margin and any palpable preauricular lymph nodes. Corneal staining is imperative to rule out HSV dendritic ulcers: if in doubt, refer to specialist team to assess for keratitis as this may lead to complications including scarring and severe complications such as perforation and visual loss.
• Management - in the absence of corneal involvement: conservative management is appropriate for this self-limiting condition which usually resolves within 2-3 weeks.⁶ Where there is corneal involvement (or if there has been corneal involvement in previous episodes), discontinue contact lens wear until the patient is cleared by an ophthalmological assessment, topical antiviral treatment, such as aciclovir, is the norm with referral to ophthalmologists. If the keratitis is found to be extending deep into the stroma, topical steroids may be used but this is only done under specialist supervision. Some patients with recurrent HSV keratitis are on kept on long term prophylactic oral antivirals.⁷

Molluscum contagiosum conjunctivitis

• Essence^1,2 - this oncogenic virus generally infects the skin but occasionally spreads to mucous membranes (including the conjunctiva) of adolescents and young adults. It is commonly found in AIDS patients.
• Risk factors¹ - patients in an immunocompromised state.
• Signs to look for^2,3 - uni- / bilateral, single / multiple, dome-shaped umbilicated shiny nodules on eyelid or lid margin. There may be conjunctival follicles ± a corneal pannus (conjunctiva creeping across the cornea).
• Management - refer to ophthalmologists for excision, cryotherapy or cauterisation.

More commonly encountered allergic conjunctivitis

• Essence - hypersensitivity reaction to specific allergens. There are four recognised types:
  • Seasonal (a.k.a. hay fever), the commonest allergen being pollen. This tends to recur at the same time each year, often in atopic individuals.
  • Perennial, where symptoms occur throughout the year in response to various allergens such as dust mites. Symptoms may be worse in the mornings.
  • Giant papillary - common causes include contact lenses, sutures and prostheses following eye surgery.
  • Contact dermatoconjunctivitis which tends to arise in response to eye drops of cosmetics. It is characterised by a complete lack of response to antihistamines and mast cell stabilizers.
• Suggestive symptoms - itchy watery red eyes ± skin irritation in contact dermatoconjunctivitis.
• Signs to look for - lid oedema or conjunctival chemosis, papillae.
• Management - general measures include:
  • Avoid allergen where possible
  • Avoid wearing contact lenses until symptoms and signs resolve
  • Avoid rubbing the eyes
  • Cool compresses and preservative-free lubricants may also help
  If severe, rapid relief can be obtained with an oral or topical anti-histamine. For more long-term management, consider a topical mast cell stabiliser and oral or topical antihistamines (other than in contact dermatoconjunctivitis which is unresponsive to these). A 3 to 5 day course or oral corticosteroids can be used if symptoms are very severe but there must be absolutely no doubt about the diagnosis.

Patients experiencing giant papillary conjunctivitis following surgery should be referred to the ophthalmologists. Also consider referral where contact dermatoconjunctivitis is severe or where an alternative eye drop needs to be prescribed (e.g. for glaucoma).

Vernal conjunctivitis²

• Essence - this is an IgE and cell-mediated allergic condition mainly affecting boys (usually after the age of 5) and young men (rarely persisting beyond 25 years old) living in warm conditions.² It may be seasonal or perennial. Think of this in patients not responding to conventional treatment (see above).⁸
• Risk factors - atopy (patient, family history), associated keratoconus (possible cause, possible effect) and other types of corneal malformations.
• Suggestive symptoms³ - intense itching, thick ropey mucous discharge.
• Signs to look for³ - large upper lid papillae, raised white mucoid nodules arranged around the limbus (margin) of the cornea; occasionally a ptosis is also present.
• Management - refer to ophthalmologists as topical steroids may need to be added to conventional treatment for allergic conjunctivitis and occasionally, serious corneal complications can occur from this disease.

Atopic conjunctivitis²

• Essence - a relatively rare but potentially serious condition affecting mainly young men suffering from atopic dermatitis. Presentation can be similar to vernal conjunctivitis but persists for years and is associated with significant visual morbidity secondary to keratoconus, presenile cataract and occasionally, retinal detachment.
• Signs to look for - red, thickened and occasionally fissured lids, cicatrisation of the conjunctiva in advanced cases, keratopathy, evidence of concurrent infections such as herpes simplex and microbial keratitis.
• Management - as for vernal conjunctivitis.

Giant papillary conjunctivitis

Irritant conjunctivitis which comes about gradually in response to prolonged contact wear, presence of ocular prosthesis or to exposed corneal sutures. It is characterised by papillary hypertrophy, a mucoid discharge and in severe cases, ptosis. The irritant is removed and topical mast cell stabilizers are used.

Superior limbic keratoconjunctivitis

This is an uncommon, chronic condition affecting mainly middle-aged women with thyroid dysfunction. Patients complain of non-specific conjunctivitis-type symptoms (foreign body sensation, burning, mucoid discharge) that wax and wane over many years before eventually resolving. There is thickening of the conjunctiva around the superior corneal limbus and a corneal pannus as well as punctate epithelial erosions may be present. Aggressive lubrication and occasionally, anti-inflammatories are used.

Floppy eyelid syndrome

This is a chronic irritation occurring more often in obese patients with sleep apnoea. Nocturnal eyelid ectropion results in conjunctival contact with bedding. It can occasionally lead to corneal scarring. There will be upper eyelid swelling, diffuse papillary reaction and there may be a pannus. Temporary relief can be achieved with lubricants and taping of the lid. Definitive treatment is surgical.

Toxic conjunctivitis

Prolonged (>1 month) use of aminoglycosides, antivirals, drops with preservatives and inappropriate use of over the counter preparations containing vasoconstrictors may give rise to an irritant conjunctivitis. Diagnosis is made by exclusion. There will be conjunctival hyperaemia and follicles. Discontinue offending agent.

Parinaud oculoglandular syndrome

This rare condition can arise as a result of cat scratch disease, tularaemia, sporotrichosis, tuberculosis, syphilis and infectious mononucleosis. It presents with generalised malaise and a unilateral conjunctivitis. It responds to treatment of the underlying cause.

Pediculosis (lice, crabs)

A uni-/bilateral infection arising from contact with pubic lice. It gives rise to itching and adult lice will be seen on the lids. Mechanical removal of the lice and their eggs needs to be carried out and an ophthalmic anti-microbial ointment is used for the lashes in association with anti-lice treatment to the rest of the body (patient and sexual partners).