Conjunctivitis: Types, Symptoms & Treatment

What are the symptoms of allergic conjunctivitis?

Symptoms usually appear immediately after contact with the allergen, although in some cases the reaction may be delayed. The most common symptom is itching, accompanied by redness. There may be mild pain and a foreign body sensation in the eye, which leads to watering, a constant flow of tears from the eyes. Finally, in advanced stages, blurred vision and sensitivity to light begin to appear. The symptoms of allergic conjunctivitis have a lot in common with blepharitis and dry eye, so in the early stages patients may confuse them, although this is very easily resolved with an eye examination.

 

Who is likely to develop allergic conjunctivitis?

Allergic conjunctivitis can develop at any age. However, we have observed that it is more common in children and young adults aged 12 to 30.

Men and women are affected equally, while people who come into contact with allergens at home or at work are clearly more likely to develop the condition.

A family history of allergies also plays an important role, that is, whether a family member has a history of allergies.

Finally, conditions such as asthma or eczema can trigger allergic conjunctivitis.

How is allergic conjunctivitis diagnosed?

The first and most important step in the diagnosis is taking a complete and detailed history of the condition and of the patient. A slit lamp examination then gives us the necessary findings, while in particularly complex cases a blood test can confirm that it is an allergic reaction.

Can an allergic reaction have permanent effects on the eye and vision?

Very rarely, and in particularly severe cases, the cornea may be affected. The cornea is the transparent tissue located directly in front of the iris. It is meant to be transparent, and this is what can be affected, mainly in chronic conjunctivitis. Because of chronic irritation, it tends to lose its clarity. In such cases there is also, for the same reason, an increased risk of bacterial infections of the cornea.

How easily can this condition be treated?

The first aim of both treatment and prevention is to remove the allergen, if this is possible. Beyond that, there is a wide range of eye drops with anti-allergic and anti-inflammatory action, which treat the majority of cases very well. Cold compresses can bring significant relief, while contact lenses should be avoided.

Is conjunctivitis contagious?

It depends on the type. Viral and bacterial conjunctivitis spread easily, while allergic conjunctivitis is not contagious. It is passed on mainly through the hands, when we touch our eyes and then surfaces or other people, and through shared towels, pillowcases or cosmetics.

To protect the people around you and your other eye:

• wash your hands often with soap, especially after touching your eyes or using your drops,
• use your own towel and change your pillowcase often,
• wipe away discharge with a disposable tissue, using a separate one for each eye,
• do not wear contact lenses until the infection has fully cleared, and replace your lenses and their case,
• do not share eye cosmetics, and throw away any you used during the infection.

Viral conjunctivitis remains contagious for as long as the eye is red and watering, often for 10-14 days. Bacterial conjunctivitis usually becomes much less contagious 24-48 hours after starting the right treatment.

How long does conjunctivitis last?

How long it lasts depends mainly on the cause:

• Viral: usually 1-2 weeks, sometimes up to 3. Symptoms often get worse during the first 3-5 days before they start to settle. In some forms, mild blurring may persist for weeks because of small opacities in the cornea.
• Bacterial: usually improves within a few days with the right treatment, while without treatment it may last longer.
• Allergic: lasts as long as there is exposure to the allergen. The seasonal form appears every spring or autumn, while the chronic form, caused by dust or pet hair, may persist all year round.

If conjunctivitis does not improve after one week, gets worse while you are on treatment or keeps coming back, it needs to be reassessed. Sometimes behind a “conjunctivitis that won’t go away” there is blepharitis, dry eye or a reaction to an eye drop.

Conjunctivitis in children

Children often get conjunctivitis, mainly viral or bacterial, as it spreads easily at nursery and school. The bacterial form is sometimes accompanied by an ear infection. Allergic conjunctivitis usually appears in children with asthma, allergic rhinitis or eczema.

Useful practical advice:

• clean away discharge with sterile gauze and saline, wiping from the inner corner of the eye outwards,
• keep your child’s nails short and discourage eye rubbing,
• your child can return to nursery or school on the doctor’s advice, usually once treatment has started and the discharge has settled.

Any red eye in a newborn during the first weeks of life needs to be examined straight away, as does a child with pain, sensitivity to light, a swollen red eyelid with fever, or poor vision. If conjunctivitis keeps coming back, a full examination by an ophthalmologist experienced in paediatric ophthalmology is worthwhile.

Conjunctivitis from viral infections such as coronavirus

Many viruses that cause colds or flu can also infect the conjunctiva. The most common is adenovirus, which causes the highly contagious epidemic keratoconjunctivitis, often with a swollen lymph node in front of the ear.

The SARS-CoV-2 coronavirus causes conjunctivitis in a small percentage of patients. It is usually mild, with redness, watering and a gritty feeling, may appear before or together with the other symptoms, and settles without specific treatment. The virus has been detected in tears, so hand hygiene matters here too.

Some viruses need closer attention. The herpes simplex virus usually affects one eye and can spread to the cornea, while herpes zoster (shingles) on the forehead and nose is often accompanied by eye involvement. In these cases, steroid eye drops used without an examination can make the condition worse.

See an ophthalmologist if the redness comes with pain, blurred vision, sensitivity to light or a rash around the eye.

Viral conjunctivitis in detail

Viral conjunctivitis is the most common form of infectious conjunctivitis in adults. It is mainly caused by adenoviruses, the same viruses that cause colds and sore throats. It usually starts in one eye and spreads to the other within a few days. Typical features are marked redness, watery discharge, a gritty feeling, swollen eyelids and often an enlarged lymph node in front of the ear.

In a more severe form, epidemic keratoconjunctivitis, the virus also affects the cornea. Once the redness has settled, small opacities may appear in the cornea, causing blurred vision and sensitivity to light for weeks or months. In these cases the ophthalmologist may prescribe mild anti-inflammatory treatment with close monitoring. Antibiotics do not help in viral conjunctivitis.

Bacterial conjunctivitis

Bacterial conjunctivitis is more common in children. It is characterised by thick, yellow-green discharge that sticks the eyelashes together, especially in the morning. It is usually treated with antibiotic eye drops or ointment for a few days. In newborns, or when the discharge is very heavy and the condition gets worse quickly, an immediate examination is needed, because some bacteria can cause serious damage to the cornea.

Conjunctivitis from contact lenses

Contact lens wearers may develop a particular form of allergic reaction called giant papillary conjunctivitis. Small bumps form on the inside of the upper eyelid, the lenses “ride up” and cloud over quickly, and they become harder to tolerate. Treatment involves stopping lens wear for a period, suitable eye drops and often switching to daily disposable lenses.

Caution: a red, painful eye in a contact lens wearer, especially with sensitivity to light or blurred vision, may be a corneal infection rather than simple conjunctivitis. Remove your lenses and get examined the same day.

Chemical irritation: first aid

If chlorine, detergent, lime, cement or another chemical gets into the eye, rinsing is the most important step and must be done immediately. Rinse with plenty of clean water for at least 10 to 15 minutes, holding the eyelids open. Then see an ophthalmologist urgently, especially in the case of alkaline substances such as lime and drain cleaners, which can cause serious damage.

How to stop it spreading

• wash your hands often with soap and water
• do not touch or rub your eyes
• use your own towel and pillowcase and change them often
• do not share eye drops, cosmetics or glasses
• throw away eye cosmetics you used while you had the infection
• do not wear contact lenses until the eye has fully healed

When can I go back to work or school?

In viral conjunctivitis, the patient is contagious for as long as the eyes are red and watering, usually for about one to two weeks. In jobs with close contact with others, especially in healthcare settings, it is best to avoid working during this time. In bacterial conjunctivitis, contagiousness drops significantly after one to two days of antibiotic treatment. Allergic conjunctivitis is not contagious.

When a red eye is not conjunctivitis

Not every red eye is conjunctivitis. Other, more serious conditions may look similar at first, such as iritis and other forms of eye inflammation, acute glaucoma or a corneal ulcer. You need an urgent examination if there is:

• severe pain inside the eye, not just irritation
• reduced or blurred vision that does not clear when you blink
• marked sensitivity to light
• a pupil with an unusual shape or size
• headache and nausea together with a red eye
• an injury or contact lens use

Dr. Vasileios Skouteris examines adults and children with red eyes and conjunctivitis at his clinic in Neo Psychiko, Athens. To book an appointment, call 210 677 0007.

Relief at home: what helps

• Cold compresses: reduce swelling and itching, especially in the allergic and viral forms.
• Preservative-free artificial tears: “wash out” allergens and germs and relieve the gritty feeling. They can be kept in the fridge for extra cooling.
• Cleaning the eyelids: with clean gauze and lukewarm water to remove discharge, using a different piece of gauze for each eye.
• Sunglasses: help when there is sensitivity to light.
• A break from screens: an inflamed eye tires more easily.

Avoid “whitening” eye drops and do not use steroid eye drops without a medical examination. Steroids can make some infections worse, such as those caused by the herpes virus, and with long-term use they can raise the pressure in the eye.

Year-round allergic conjunctivitis

Apart from seasonal spring allergy, there is also perennial allergic conjunctivitis, caused by house dust mites, pet hair or household moulds. The symptoms are milder but persistent. As well as anti-allergy eye drops, it helps to air the house often, wash bedding at a high temperature, use mattress covers and keep pets out of the bedroom.

Conjunctivitis in newborns

In newborns, red eyes with discharge during the first weeks of life always need to be examined by a doctor. The cause may be simple, such as a blocked tear duct that causes watering and sticky eyes, but it may also be an infection that needs immediate treatment. Do not use eye drops or home remedies such as breast milk or chamomile on babies without medical advice.

Diagnosis in the clinic

In most cases the diagnosis is clinical. With the slit lamp we examine the conjunctiva and the inner surface of the eyelids, the type of discharge, the cornea with a dye, and the lymph nodes. In persistent or atypical cases, a sample may need to be taken for culture or special testing. The right diagnosis avoids the unnecessary use of antibiotics and steroids.

Most of the time, conjunctivitis is mild and clears up in a few days. However, when symptoms persist, get worse or affect your vision, an examination by an ophthalmologist gives the right diagnosis and fast relief.

For children who go to school or nursery, the paediatrician or ophthalmologist will tell you when they can safely return.

Frequently Asked Questions about Conjunctivitis

Medically reviewed by: Dr. Vasileios Skouteris MD, FEBO