BASICS

DESCRIPTION

• Allergic conjunctivitis is an allergic inflammation of the ocular surface that can be divided into the following categories: seasonal and perennial allergic conjunctivitis (SAC and PAC), vernal keratoconjunctivitis (VKC), atopic keratoconjunctivitis (AKC), and giant papillary conjunctivitis (GPC).

– SAC: Conjunctival inflammation occurring at a specific time of year

– PAC: A variant of SAC that occurs throughout the year

– VKC: Bilateral, chronic inflammatory condition of the conjunctiva with possible corneal involvement

– AKC: Bilateral, chronic inflammatory condition associated with atopic dermatitis

– GPC: Inflammatory condition affecting superior tarsal conjunctiva

EPIDEMIOLOGY

• Allergic conjunctivitis affects up to 40% of the population.

• Atopic dermatitis affects up to 3% of the population and ocular involvement occurs in 25–40% of these individuals.

RISK FACTORS

• Personal or family history of atopic conditions including eczema, asthma, hay fever, and allergic rhinitis:

– Exposure to aeroallergens to which an individual has a known allergy

– GPC: Use of soft or rigid gas permeable lenses, ocular prosthesis or foreign body

Genetics

Hereditary background of atopic conditions is common.

GENERAL PREVENTION

Avoidance of known allergens

PATHOPHYSIOLOGY

• Activation of mast cells by antigens results in release of chemical mediators (i.e., histamine).

– SAC/PAC: Type I hypersensitivity reaction

– AKC/VKC: Type I and IV hypersensitivity reaction

– GPC: Trauma to upper lid

ETIOLOGY

• SAC: Grass and pollen allergens

• PAC: Indoor allergens such as dust mites and animal dander

• VKC/AKC: Multiple environmental allergens

• GPC: Foreign body causing irritation to upper lid

COMMONLY ASSOCIATED CONDITIONS

Atopic disease

DIAGNOSIS

HISTORY

• Itching, burning, irritation, photophobia, tearing, watery discharge:

– SAC: Occurs at a specific time to known allergens.

– PAC: Occurs throughout the year but may be worse at specific times.

– VKC: Severe itching. Bilateral. Predilection for young males from hot, dry climates (Mediterranean, Africa). Seasonal exacerbation. Affects most prior to puberty and resolves by late teens/early twenties.

– AKC: Older population. Symptoms may occur year round and is not associated with hot weather.

– GPC: Contact lens use, suture, foreign body.

PHYSICAL EXAM

• SAC/PAC: Mild conjunctival injection and edema. Papillary reaction, but no giant papillae.

• VKC: Conjunctival injection, giant papillae, involvement of upper palpebral conjunctiva. Limbal thickening, limbal nodules, Trantas’ dots. Corneal involvement: punctuate keratopathy, erosions, shield ulcer, plaque, pannus.

• AKC: Conjunctival injection, atopic dermatitis of lids, papillary hypertrophy. Corneal involvement: pannus, ulcer, scarring. Cataract.

• GPC: Giant papillae, upper palpebral conjunctiva.

DIAGNOSTIC TESTS & INTERPRETATION

Lab

• Not typically necessary

– Conjunctival scraping

Diagnostic Procedures/Other

Conjunctival provocation test

Pathological Findings

Eosinophils on conjunctival scraping

DIFFERENTIAL DIAGNOSIS

Viral conjunctivitis, dry eye, blepharitis, contact dermatitis, toxic/chemical conjunctivitis, floppy eyelid syndrome/eyelid imbrication

TREATMENT

MEDICATION

First Line

• SAC/PAC: Topical antihistamine-vasoconstrictor eye drops (antazoline/naphazoline 0.5/0.05%: 1 drop q.i.d. PRN)

• SAC/PAC: Topical antihistamine (levocabastine 0.05%, emedastine 0.05% q.i.d. OU), mast cell stabilizer (lodoxamide 0.1% or pemirolast 0.1% q.i.d.), or antihistamine with mast cell stabilizing properties (olopatadine 0.1% b.i.d. or 0.2% per day, azelastineepinastine 0.05%, ketotifen 0.025%, or bepotastine 1.5% b.i.d.)

• VKC/AKC: Topical steroid (prednisolone acetate up to 8 times per day) in addition to mast cell stabilizer or antihistamine with mast cell stabilizing properties. Topical steroids should be tapered to least possible dosing.

• GPC: in mild cases, modification of lens hygiene and use may be sufficient. Contact lens holiday or limitation of use. Antihistamine or mast cell stabilizer may help with symptoms. Use of enzymatic lens cleaners to remove surface debris from contact lenses

Second Line

• SAC/PAC: Topical steroid may be used in severe cases. Oral antihistamines used in systemic disease may help with ocular symptoms.

• VKC/AKC: Oral steroid or antihistamine in addition to the above measures. Topical cyclosporine A (i.e., restasis or up to 2% compound)

ADDITIONAL TREATMENT

General Measures

Avoid allergens. Seek cool climate, air-conditioned environment.

Issues for Referral

Corneal involvement. Vision threatening disease.

Additional Therapies

• Artificial tears to soothe the ocular surface. In VKC or AKC, artificial tears may prevent epithelial breakdown.

– Preservative-free artificial tears may be used frequently (i.e., every 1–2 h).

SURGERY/OTHER PROCEDURES

VKC/AKC: Superficial keratectomy may be indicated if corneal plaque develops. Occlusive therapy (i.e., tarsorrhaphy) may be helpful in persistent epithelial defect/ulcer refractory to other measures.

ONGOING CARE

FOLLOW-UP RECOMMENDATIONS

VKC and AKC should be followed closely for corneal involvement and risk to vision.

Patient Monitoring

Monitor vision. With topical steroid use, monitor intraocular pressure and lens changes.

PATIENT EDUCATION

Risks of topical steroid use include glaucoma, cataract formation, and predisposition to infection.

PROGNOSIS

• SAC/PAC/GPC: good prognosis

• VKC/AKC: prognosis can be guarded with corneal involvement.

COMPLICATIONS

• Corneal complications (scarring, pannus). Loss of vision.

– Most likely to occur with VKC or AKC

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