Aetiology

A self-limiting urticarial reaction to an allergen (often unidentified) that comes into contact with the conjunctiva provoking an immediate (Type I) IgE-mediated response
Common in children
Allergens include: grass pollen, animal dander

Predisposing factors

History of allergic disease; can also occur without such history

Symptoms of acute allergic conjunctivitis

Sudden eyelid swelling
Ocular itching
May be unilateral (if a direct contact response)

Signs of acute allergic conjunctivitis

Lid oedema and erythema
Conjunctival hyperaemia and chemosis (oedema): may bulge over lid margin or limbus
Watery or mucoid discharge (mild)
Usually no papillae
No corneal involvement

Differential diagnosis

Seasonal allergic conjunctivitis
Chemical trauma
Insect bite or sting
Preseptal or orbital cellulitis

Management by optometrist

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

Reassure patient: most cases resolve spontaneously within a few hours
Advise against eye rubbing (causes mechanical mast cell degranulation)
Cool compresses may give symptomatic relief
(GRADE*: Level of evidence=low, Strength of recommendation=strong)

If possible identify allergen (take careful history) and advise future avoidance
Advise patient to return/seek further help if symptoms persist

Not normally required (although ocular lubricant drops and/or topical anti-histamines may provide symptomatic relief)
(GRADE*: Level of evidence=low, Strength of recommendation=strong)

If condition recurrent, prescribe prophylactic topical mast cell stabiliser, e.g. gutt. sodium cromoglicate 2% (as POM), or gutt lodoxamide 0.1%, or dual-acting antihistamine/mast cell stabiliser, e.g. gutt. olopatadine 0.1% (off-label use), or gutt ketotifen 0.025% (off-label use)
(GRADE*: Level of evidence=low, Strength of recommendation=weak)

Management category

B2: alleviation/palliation – normally no referral

Possible management by ophthalmologist

Not normally referred

Evidence base

*GRADE: Grading of Recommendations Assessment, Development and Evaluation (see www.gradingworkinggroup.org)

Sources of evidence

Bilkhu PS, Wolffsohn JS, Naroo SA, Robertson L, Kennedy R. Effectiveness of non-pharmacologic treatments for acute seasonal
allergic conjunctivitis. Ophthalmology. 2014;121(1):72-78.

Buckley RJ. Allergic eye disease – a clinical challenge. Clinical &Exp Allergy 1998;28:39-43

del Cuvillo A, Sastre J, Montoro J, Jáuregui I, Dávila I, Ferrer M, Bartra J, Mullol J, Valero A. Allergic Conjunctivitis and H1 Antihistamines. J Investig Allergol Clin Immunol. 2009;19,Suppl.1:11-18

Conjunctivitis (Acute Allergic)
Version 14
Date of search 08.12.22
Date of revision 23.02.23
Date of publication 30.03.23
Date for review 07.12.24
© College of Optometrists