Conjunctivitis (bacterial)

The CMGs are guidelines on the diagnosis and management of a range of common and rare, but important, eye conditions that present with varying frequency in primary and first contact care.

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

  • Staphylococcus species
  • Streptococcus pneumoniae
  • Haemophilus influenzae
  • 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
  • recent cold, upper respiratory tract infection [NB refer also to Clinical Management Guideline on Conjunctivitis (viral, nonherpetic)] or sinusitis
  • diabetes (or other disease compromising the immune system)
  • steroids (systemic or topical, compromising ocular resistance to infection)
  • blepharitis (or other chronic ocular inflammation)


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)


  • lid crusting
  • purulent or mucopurulent discharge
  • conjunctival hyperaemia – maximal in fornices
  • tarsal conjunctiva may show mild papillary reaction
  • cornea: usually no involvement (occasionally punctate epitheliopathy – 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

  • epidemic keratoconjunctivitis (e.g. adenovirus)
  • Herpes simplex or Herpes zoster
  • Chlamydial infection
  • allergy

Other causes of acute red eye

  • angle closure glaucoma
  • infective keratitis
  • anterior uveitis

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

Often resolves in 5-7 days without treatment
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


Treatment with topical antibiotic may improve short-term outcome and render patient less infectious to others
(GRADE*: Level of evidence = high, Strength of recommendation = strong)

Alternatives 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. Patients with purulent discharge or a mild severity of red eye were found to benefit most from treatment with antibiotics

Contact lens wearers with a diagnosis of bacterial conjunctivitis should be treated with a topical antibiotic effective against Gram –ve organisms, e.g. a quinolone such as levofloxacin or moxifloxacin, or an aminogycoside such as gentamicin. 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.

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. Guidance on Infection Control in Schools and other Childcare Settings. March 2017

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 with associated discomfort. The condition is not normally serious and in most cases clears up 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 be less 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 12
Date of search 17.07.18
Date of revision 20.07.18
Date of publication 20.12.18
Date for review 16.07.20
© College of Optometrists 

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