Conjunctivitis (Acute Allergic)

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

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

Signs

Lid oedema and erythema
Conjunctival 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
Preseptal or orbital cellulitis

Management by optometrist

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

Non pharmacological

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 and advise future avoidance
Advise patient to return/seek further help if symptoms persist

Pharmacological

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-licence use), or gutt ketotifen 0.025% (off-licence use); maximum
duration 4 months
(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 http://www.gradingworkinggroup.org/index.htm)
 

Sources of evidence

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

Lay summary

Acute allergic conjunctivitis is an allergic reaction of the eyes, which causes a sudden swelling and redness of the eyelids and conjunctiva (the membrane covering the white of the eye), often associated with itching. It usually occurs in susceptible individuals, typically following exposure to grass pollen or animal fur. Most cases get better within a few hours without the need for drug treatment. However, anti-allergy eye drops may help to control symptoms in the short term and in people with recurrent episodes.

Conjunctivitis (Acute Allergic)
Version 12
Date of search 25.11.18
Date of revision 29.13.19
Date of publication 09.05.19
Date for review 24.11.20
© College of Optometrists

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