It’s a classic presentation. Your patient is a toddler with a sticky red eye that – despite their parent’s best efforts to pull their hands away from their face – they cannot help but rub.
Their parent is asking you if it’s contagious and if they need antibiotics.
Conjunctivitis: An overview
Conjunctivitis, inflammation of the conjunctiva, is characterised by infection or inflammation of the conjunctiva. It presents with conjunctival vessel dilatation, oedema and discharge. Symptoms include eye discharge, itching and redness.
It is common. One in eight children gets conjunctivitis at least once a year.
Conjunctivitis can be infective or allergic.
Common pathogens
Around 20% of cases in children are viral – most commonly adenoviruses, enteroviruses or coxsackieviruses.
Most cases in children are bacterial. Bacteria may cause conjunctivitis on their own or in conjunction with viruses. The common culprits are Staphylococcus aureus, Streptococcus pneumonia and Haemophilus influenzae. Less commonly, conjunctivitis is caused by Chlamydia spp., Neisseria gonorrhoea and Neisseria meningitidis.
Infective conjunctivitis, in general, is a benign self-limiting disease. However, it is often difficult to differentiate between viral and bacterial causes, so topical antibiotics are often prescribed. This brings about a risk of antibiotic resistance, increased healthcare costs and potential side effects.
Viral or bacterial conjunctivitis? Perhaps both? Does it even matter?
80% of conjunctivitis in children is due to bacteria, alone or alongside a virus. You would expect that if most cases are bacterial, treating with antibiotics should be more beneficial. However, there is no significant difference in clinical cure rate between children treated with chloramphenicol and those left alone. Additionally, NICE CKS advises us that ‘most cases of bacterial conjunctivitis are self-limiting and resolve within 5-7 days without treatment’.
Although antibiotics reduce the bacteria burden after treatment and speed resolution by half a day, there appear to be no long-term adverse effects of conservative management.
Neonatal conjunctivitis
Neonatal conjunctivitis is inflammation of the conjunctiva in the first 30 days of life.
In the past, ophthalmic silver nitrate was used as prophylaxis for ocular gonococcal infections. This led to chemical-induced conjunctivitis. Now, we use erythromycin ointment instead.
Chlamydia trachomatis is the most common bacterial cause. Other organisms include N.gonorrhea, S aureus, and Pseudomonas aeruginosa. Viral causes include the Herpes simplex virus.
Neonatal conjunctivitis should be diagnosed and treated promptly, as complications such as corneal opacification, corneal perforation, loss of the eye and blindness can result if it is left untreated. N. gonorrhoea, in particular, can penetrate intact corneal membranes.
Chlamydia has a longer incubation period, and onset is usually at 5-14 days of life. It can start in one eye only but usually spreads to both eyes and presents as purulent discharge with lid oedema. Chlamydial conjunctivitis can present earlier if there is a premature rupture of membranes. Vertical transmission rates are up to 66%, and 25% of babies born to mothers with chlamydia get infections, with a quarter of these being pneumonia and the rest with conjunctivitis. Babies with suspected chlamydia should have an eye swab sent and be commenced on 0.5% chloramphenicol drops and oral erythromycin (or azithromycin). If untreated, 1 in 5 babies with chlamydia conjunctivitis will develop pneumonia.
Gonococcal eye infection is less common and has a 2-5 day incubation period. If a baby presents in the first 5 days of life with a bilateral purulent discharge and tense lid oedema, then consider gonococcal infection. Swabs should be sent for (urgent) gram stain and culture, and the baby should be started immediately on IV cefotaxime. Chloramphenicol drops can also be given. Complications include corneal ulceration, meningitis, or sepsis.
What do the guidelines say about the management of infective conjunctivitis in children?
NICE recommend conservative management of acute conjunctivitis provided there are no features of complicated or severe disease are present.
Conservative management includes washing hands to prevent spread, avoiding close contact with others, using cool compresses, and bathing eyes in sterile saline. They do not recommend Immediate antibiotic prescription, and exclusion from nursery or school is not necessary. After seven days, if there is no clinical improvement, consider sending swabs for culture and adding in antibiotics.
Using a delayed prescription strategy is a good compromise. No one antibiotic is better than any other; NICE recommends a broad-spectrum topical antibiotic such as chloramphenicol. The benefits of topical chloramphenicol outweigh the risks in children of all ages – caution only in excessive use in neonates with hepatic impairment.
When to refer to Ophthalmology
A referral to Ophthalmology is indicated if there are certain adverse features: severe pain, visual loss, immunocompromised, or if the patient wears contact lenses. It’s also worth referring if there are features suggesting problematic pathogens, such as gonococcus, are present, e.g. purulent discharge, history of exposure or risk of sexually transmitted infection, and pain.
Children with Neisseria gonorrhoea and Chlamydia trachomatis should get systemic antibiotics: macrolides for chlamydia and ceftriaxone or doxycycline for gonorrhoea.
Sexually transmitted infections may cause conjunctivitis in the newborn through vaginal delivery. Otherwise, conjunctivitis caused by STIs is uncommon in children. It should trigger concern for sexual abuse.
Chlamydial conjunctivitis: Public Demain
What about allergic conjunctivitis?
In contrast to infective conjunctivitis, allergic conjunctivitis is due to an inflammatory response to an allergen. There is no infective pathogen present. It is often associated with atopy. Itching, excessive conjunctival oedema and lacrimation point towards the diagnosis of allergic conjunctivitis.
Allergic conjunctivitis can be subdivided into different forms.
Seasonal allergic conjunctivitis occurs after an IgE hypersensitivity reaction to an allergen like pollen and tends to recur seasonally.
Vernal keratoconjunctivitis typically affects young boys or adolescents in hot climates during spring and summer.
Atopic keratoconjunctivitis is similar to vernal keratoconjunctivitis, though it often continues into adulthood. Individuals can suffer acute-on-chronic exacerbations.
Giant papillary conjunctivitis occurs with mechanical damage, such as contact lens wear, and is less common in children.
How do you manage allergic conjunctivitis?
Allergic conjunctivitis can be managed conservatively. This centres on the alleged avoidance if the trigger is known. Patients should be encouraged to avoid rubbing their eyes, though this is easier said than done in younger children. Parents can help their children by using a cold compress on the eyes for 10 minutes twice daily and/or applying artificial tear drops to provide symptomatic relief.
For some children, this may not be enough, and they may require medicated drops. Broadly speaking, eye drops for allergic conjunctivitis come in three classes: anti-histaminergic, mast cell stabilisers and combined (uses both mechanisms of action).
Sodium cromoglicate is a mast cell stabiliser. This topical preparation is licensed for use in all children. Many other drops – e.g. azelastine (a dual-acting mast cell stabiliser and anti-histamine) – are only licensed for children above a certain age. Specialist referral may be indicated for children when there is diagnostic uncertainty when their quality of life is impaired by their allergic conjunctivitis, or they also have respiratory symptoms.
References
Azari AA, Barney NP. Conjunctivitis: a systematic review of diagnosis and treatment. Jama. 2013 Oct 23;310(16):1721-30.
McCormick M, Fleming D, Charlton J. Morbidity statistics from general practice: fourth national survey 1991–1992. London: HMSO, 1995
Rose PW, Harnden A, Brueggemann AB, Perera R, Sheikh A, Crook D, Mant D. Chloramphenicol treatment for acute infective conjunctivitis in children in primary care: a randomised double-blind placebo-controlled trial. The Lancet. 2005 Jul 2;366(9479):37-43.
Sheikh A, Hurwitz B, van Schayck CP, McLean S, Nurmatov U. Antibiotics versus placebo for acute bacterial conjunctivitis. Cochrane Database of Systematic Reviews. 2012(9).
Kapoor VS, Evans JR, Vedula SS. Interventions for preventing ophthalmia neonatorum. Cochrane database of systematic reviews. 2020(9).
NICE CKS. Conjunctivitis – Management in primary care. cks.nice.org.uk/topics/conjunctivitis-infective/management/management-in-primary-care/(accessed 19 January 2024)
Azari AA, Barney NP. Conjunctivitis: a systematic review of diagnosis and treatment. Jama. 2013 Oct 23;310(16):1721-30.
Sheikh A, Hurwitz B, van Schayck CP, McLean S, Nurmatov U. Antibiotics versus placebo for acute bacterial conjunctivitis. Cochrane Database of Systematic Reviews. 2012(9).
BNFC. Chloramphenicol. bnfc.nice.org.uk/drugs/chloramphenicol/(accessed 21 January 2024)
NICE CKS. Conjunctivitis – allergic – Management in primary care. cks.nice.org.uk/topics/conjunctivitis-allergic/management/management-in-primary-care/ (accessed 21 January 2024)
BNFC. Sodium cromoglicate. bnfc.nice.org.uk/drugs/sodium-cromoglicate/ (accessed 21 January 2024)
NHS. Who can and cannot use sodium cromoglicate eye drops? www.nhs.uk/medicines/sodium-cromoglicate-eye-drops/who-can-and-cannot-use-sodium-cromoglicate-eye-drops/ (accessed 21 January 2024)
