Conjunctivitis is inflammation of the conjunctiva, the mucous membrane lining the
anterior sclera and inner eyelid surfaces, seen in the broad spectrum of conditions,
Allergic inflammation of the ocular surface (the lid margins, conjunctiva and cornea
is one of the commonest eye disorders.
In its mildest form, the conjunctiva
becomes inflamed in response to a transient allergen (e.g. pollen in seasonal allergic
A persistent allergen (e.g.
house dust mite in perennial allergic conjunctivitis) producing unpleasant symptoms
but not threatening sight.
At the other end of the spectrum are disorders with blinding complications such
as vernal keratoconjunctivitis and Atopic keratoconjunctivitis.
Classification of Allergic Conjunctivitis
Seasonal allergic conjunctivitis
or Hay Fever
- Perennial allergic conjunctivitis
- Atopic keratoconjunctivitis
- Vernal keratoconjunctivitis
- Giant papillary conjunctivitis
Clinical Features of Allergic conjunctivitis
History is important
Other allergic diseases like
asthma or eczema suggest allergic conjunctivitis
Use of any topical face/eye
preparations allergic dermatoconjunctivitis
Seasonal history suggest hay
fever caused by grass, tree or weed pollen, perennial (all year round) symptoms
suggest house dust mites, pets especially cats or moulds
Use of Antihistamines
may alter clinical picture
Contact lens use irritant
or allergic reaction to lens solutions
Hallmark symptom of all types
of allergic conjunctivitis is itching (pruritus) more prominent in acute cases
Photophobia with or
without decreased visual acuity, usually means keratitis is present
It is important to remember
that the eyes can be predominantly affected in hay fever, with less rhinitis symptoms,
also when patient have been on nasal steroids they will present with conjunctivitis
Three types of conjunctival reaction:
redness of conjunctiva with swelling (chemosis), periorbital swelling, mucoid discharge
- There is often eyelid eczema
- these appear as small, pale, elevated nodules, most marked in lower tarsal conjunctiva
are less specific red spots. Each papilla has a central vessel running to the surface
- are less common and much more specific. By definition, they are greater than 1mm
in diameter, with domed or flat tops. Large polygonal giant papillae with flat tops
Cobblestone appearance characteristic of vernal conjunctivitis.
Key Features of the Diagnosis of IgE-Mediated Allergic Eye Disease
which is usually intense
- Bilateral involvement, and
Associated with atopic respiratory
The absence of any of these is strong evidence against allergy.
Acute Allergic Conjunctivitis (Seasonal & perennial allergic conjunctivitis)
The pruritus usually distinguishes allergic from other causes of conjunctivitis.
Can de diagnosed by doing a conjunctival scrape looking for eosinophils.
In perennial conjunctivitis, due to house dust mites or cats, avoidance or allergen reduction measures should
be first tried along with antihistamines and if this fails immunotherapy
should be considered
This is a chronic, bilateral inflammation of the conjunctiva that is most commonly
found in children and adolescents. Males tend to be affected more often than females,
and it usually resolves by early adulthood. The effects of vernal conjunctivitis
can be so severe that blindness may result. Like allergic conjunctivitis it is immune
It usually occurs in spring and summer months, but in severe cases can be perennial.
The most remarkable finding is the intense itching and giant papillae on the tarsal
conjunctiva. Ropy mucoid discharge is also a distinguishing sign.
Vernal conjunctivitis probably represents a severe and chronic form of allergic
conjunctivitis with more intense symptoms and sequelae.
Treatment of Vernal conjunctivitis includes:
Aggressive use of mast cell
stabilisers e.g. sodium cromoglycate
- Topical antihistamines
Topical non steroidal anti-inflammatory
Topical steroids may be necessary
in severe cases
Atopic Keratoconjunctivitis (AKC)
Atopic dermatitis, although usually manifested peripherally, can have significant
eye findings. It has been estimated that up to 25% of patients with atopic dermatitis
will often have ocular (eye) involvement.
Eye involvement in AKC include:
inflammation of the cornea and conjunctiva) causing painful, watering, red eye with
blurring of vision
- Increased risk of eye infections
The pathophysiology of AKC is not known, but thought to be combination of Type 1
and Type 4 Hypersensitivity reactions
Treatment of AKC
for short periods
- Mast cell stabilizers
- Cold compresses
Careful follow-up to prevent
damage to vision
Contact allergy of the eye and periocular area occurs with a variety of cosmetics,
soaps, contact lens solution, and medications. Symptoms include redness of the conjunctiva
and periorbital swelling.
Compounds commonly causing allergic contact dermatoconjunctivitis:
Thiomersal in contact lens
- Ppolymxin B
Treatment: removal and avoidance of the offending agent, cool compresses,
antihistamines, and topical steroids. Secondary infections should be adequately
Giant Papillary Conjunctivitis (GPC)
GPC is increasingly more common with the advent of extended wear lenses. GPC is
also associated with sutures in the eye and the presence of foreign body
It is thought that the antigen responsible for the inflammatory response is located
on the surface of the foreign body. Contact lens wearers secrete a protein that
coats the lenses, and it is believed that this protein coating is responsible for
the allergic reaction
Clinically, GPC is characterized by the presence of large papillae in the tarsal
conjunctiva of the upper lid. GPC resembles vernal conjunctivitis, but almost exclusively
associated with contact lens wearers.
Treatment involves steroid, antihistamines, mast cell stabilizers,
frequent enzymatic cleaning of the lens. It will usually stop when the patient stops
wearing contact lens or the foreign body is removed.
Management of Allergic Conjunctivitis
skin prick test
should always be done to confirm the culprit
allergen, especially if the patient works with animals
is indicated in contact dermatoconjunctivitis
for house dust mite, cat, dog, all pollens
Non-specific medical therapy:
Cold compresses – may be all that is necessary in mild seasonal and perennial
Mucolytic drops – dissolves the abnormal mucus
Treatment of facial eczema in AKC – lid margin hygiene
Antihistamines – conventional topical
- Oral antihistamine preferably non sedating
- Mast cell stabilizers
These compounds are used topically to reduce mast cell degranulation, but also have
a wide range of other anti-inflammatory effects that may be relevant. They are usually
well tolerated with very few side effects. They offer a preventative action and
work most effective if taken before the onset of symptoms, where possible (e.g.
at the beginning of the pollen season) or early in the disease process. AS the onset
of action is slow (5-7 days) and stinging can occur, patient must be warned that
their eyes might feel worse to start with.
IN VKC and AKC, mast cell inhibitors act as steroid sparing agents
Cromolyn sodium is the longest established of these drugs. And both 2% and 4% drops
are available for use up to 4 times per day. Nedocromil sodium is a newer, higher
potency mast cell stabilizer that compares favourably to cromolyn and can be used
twice daily in SAC and PAC.
Lodoxamide is another recently introduced mast cell stabilizer, which may evoke
fewer stings than the other. Both nedocromil and lodoxamide have a more rapid onset
Topical steroids are very powerful in controlling allergic conjunctivitis, but have
potentially sight-threatening side effects.
Steroids are generally contraindicated in SAR & PAR; occasionally they are used
in AKC and VKC.
Topical preparation of 2% cyclosporine has been shown to provide a marked reduction
in the symptoms and signs of VKC, and cyclosporine is particularly helpful as a
Nonsteroidal anti-inflammatory agents
Topical NSAIDs appear to have some beneficial effects in allergic conjunctivitis.
Topical NSAID are not as potent as steroids but have the advantage of good ocular
safety profile and useful in treating non sight threatening conditions like SAR
and PAR when mast cell stabilizers and antihistamines fail.
Usually limited to the treatment of the sight-reducing corneal disease in AKC &
This can be useful in corneal plaques.