Conjunctivitis (bacterial)


Self-limiting bacterial infection of the conjunctiva, typically by:

  • Staphylococcus species
  • Streptococcus pneumoniae
  • Haemophilus influenzae (especially in children)
  • Moraxella catarrhalis

Predisposing factors

Children and the elderly have an increased risk of infective conjunctivitis
(NB Bacterial conjunctivitis in the first month of life is a serious condition that must be referred urgently to the ophthalmologist. See Clinical Management Guideline on Ophthalmia Neonatorum)

  • contamination of the conjunctival surface
  • superficial trauma
  • contact lens wear (NB infection may be Gram –ve)
  • secondary to viral conjunctivitis (NB refer also to Clinical Management Guideline on Conjunctivitis (viral, non-herpetic)
  • diabetes (or other disease compromising the immune system)
  • steroids (systemic or topical, compromising ocular resistance to infection)
  • blepharitis (or other chronic ocular inflammation)

Symptoms of bacterial conjunctivitis

Acute onset of:

  • redness
  • discomfort, usually described as burning or grittiness
  • discharge (may cause temporary blurring of vision)
  • crusting of lids (often stuck together after sleep and may have to be bathed open)

Usually bilateral – one eye may be affected before the other (by one or two days)

Signs of bacterial conjunctivitis

  • lid crusting
  • purulent or mucopurulent discharge
  • conjunctival hyperaemia – maximal in fornices
  • tarsal conjunctiva may show mild papillary reaction
  • cornea: usually no involvement (occasionally PEE – mainly in lower third of cornea). If cornea significantly involved, consider possibility of gonococcal infection
  • pre-auricular lymphadenopathy: usually absent

Differential diagnosis

Other forms of conjunctivitis

Other causes of acute red eye

Management by optometrist

Practitioners should recognise their limitations and where necessary seek further advice or refer the patient elsewhere

GRADE* level of evidence and strength of recommendation always relates to the statement(s) immediately above

Non pharmacological

Bathe/clean the eyelids with proprietary sterile wipes, lint or cotton wool dipped in sterile saline or boiled (cooled) water to remove crusting
(GRADE*: Level of evidence = low, Strength of recommendation = strong)

Advise patient that condition is contagious (do not share towels, etc.)
Public Health England guidance states that school or nursery exclusion is not required for children with this condition


Often resolves in 5-7 days without treatment

Treatment with topical antibiotic may modestly improve short-term outcomes and render patient less infectious to others; however the potential benefit of antibiotics needs to be balanced against the risk of antibiotic resistance
(GRADE*: Level of evidence = high, Strength of recommendation = strong)

Topical antibiotics (with no evidence of superiority of particular antibiotics) may include: chloramphenicol 0.5% eye drops, chloramphenicol 1% ointment, azithromycin 1.5% eye drops, fusidic acid 1% viscous eye drops (NB high cost and narrower spectrum of activity than chloramphenicol)
This recommendation is based on the conclusions of a Cochrane Review (Sheikh and Hurwitz 2012) which included trials conducted in primary and secondary care. However, an individual patient meta-analysis of studies exclusively based in primary care (Jefferis et al 2011) found only a marginal benefit of antibiotics over placebo. Predictors of bacterial culture positivity at presentation include purulent discharge and age less than 5 years

Contact lens wearers with a diagnosis of bacterial conjunctivitis should be treated with a topical antibiotic effective against Gram –ve organisms, such as an aminoglycoside (e.g. gentamycin) or a quinolone (e.g. levofloxacin or moxifloxacin) Contact lenses should not be worn during the treatment period
(GRADE*: Level of evidence = low, Strength of recommendation = strong).

Advise patient to return/seek further help if symptoms persist beyond 7 days

Management category

B3: management to resolution. Refer if condition fails to resolve, or if there is corneal involvement.

A3: If condition fails to resolve, or if there is corneal involvement, urgent referral (within one week) to ophthalmologist

Possible management by ophthalmologist

If resistant to treatment, or recurrent:

  • conjunctival swabs taken for microscopy and culture and/or PCR analysis
  • treatment with other antibiotics, based on culture results

Evidence base

* GRADE: Grading of Recommendations, Assessment, Development and Evaluation (

Sources of evidence

Jefferis J, Perera R, Everitt H, van Weert H, Rietveld R, Glasziou P, Rose P. Acute infective conjunctivitis in primary care: who needs antibiotics? An individual patient data meta-analysis. Br J Gen Pract. 2011;61(590):e542-8 

Public Health England South West Health Protection Team. Notes on infectious diseases in Schools and Nurseries (‘The Spotty Book’). 2017:33-34.

Sheikh A, Hurwitz B, van Schayck CP, McLean S, Nurmatov U. Antibiotics versus placebo for acute bacterial conjunctivitis. Cochrane Database of Syst Rev. 2012;9:CD001211

Plain language summary

Acute bacterial conjunctivitis is an infection of the eye in which one or both eyes become red, watery and sticky, often with discomfort but not pain. The condition is not normally serious and in most cases clears up in a few days without treatment. People with acute conjunctivitis are often given antibiotics, usually in the form of eye drops or ointment, to speed recovery. However, the benefits of antibiotics for the treatment of acute bacterial conjunctivitis have been questioned. Evidence from clinical trials in GP practices suggests that antibiotic drops may not be very helpful, since these patients tend to have a less severe form of conjunctivitis than patients who are referred to a hospital eye clinic.

Conjunctivitis (bacterial)
Version 13
Date of search 27.07.20
Date of revision 31.07.20
Date of publication 06.08.21
Date for review 26.07.22
© College of Optometrists 

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