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Conjunctivitis, or pink eye, refers to the inflammation of the conjunctiva, the thin translucent tissue that covers the inner surface of the eyelids and the outer surface of the sclera (the white portion of the eye).
Conjunctivitis can occur due to infectious and non-infectious agents and the inflammation it causes may be hyperacute, acute, or chronic.
Types of Conjunctivitis
Conjunctivitis can be viral, bacterial, allergic, or vernal.
1. Viral conjunctivitis
The most common cause of infectious conjunctivitis is viruses. Viral conjunctivitis is usually spread through hand-eye contact. An estimated 50% of the cases become bilateral due to self-inoculation. (1)
Depending on the strain, the infection can spread quite easily in public places. Symptoms that accompany viral conjunctivitis include a burning sensation in the eye, itch, redness, and clear watery discharge. (2)
2. Bacterial conjunctivitis
A bacterial infection in the eye may cause conjunctivitis, producing redness and soreness in the eyes and discharge of sticky pus.
Bacterial conjunctivitis is contagious and generally affects both eyes at once. The use of contact lenses makes you susceptible to being infected with gram-negative bacteria that cause conjunctivitis. (3)
3. Allergic conjunctivitis
4. Vernal keratoconjunctivitis
Persistent conjunctivitis in people with chronic allergies or asthma is known as vernal keratoconjunctivitis. It occurs mostly during spring and summer and especially affects boys and young men. (5)
Causes of Conjunctivitis
Conjunctivitis can result from a bacterial or viral infection or exposure to an allergen. The common agents responsible for conjunctivitis include:
1. Infectious agents
- Certain viruses that cause the common cold
- Bacteria or viruses responsible for sore throat, sinusitis, and ear infections
- Bacteria that generally cause sexually transmitted diseases (STDs) such as gonorrhea and chlamydia
- Bacteria or viruses present in the excreta (stool and urine)
2. Non-infectious agents (allergens/irritants)
- Polluting agents such as dust, chemical vapors, smoke, or fumes
- Chlorine in swimming pools
- Chemicals present in cosmetics
- Contact lenses
- Foreign bodies in the eye, such as a loose eyelash
- Amoeba and parasites
Symptoms of Conjunctivitis
The common symptoms of conjunctivitis include:
- Grittiness in the affected eye
- Redness in the eye
- Excessive tearing
- Swollen eyelids
- Itchiness or burning sensation in the eye
- Sensitivity toward light
- Watery eyes
- Puffiness in the eyes
- Crust formation on the eyelids or lashes
- Blurred vision in some cases
- Runny nose and sneezing (allergic conjunctivitis)
- Stringy discharge (allergic conjunctivitis)
- Clear, thin discharge (viral and allergic conjunctivitis)
- Green, thick discharge (bacterial conjunctivitis)
These symptoms usually appear after 24–72 hours of infection and may last from a couple of days up to 3 weeks.
Different types of viral conjunctivitis may manifest additional symptoms, including:
1. Pharyngoconjunctival fever
A syndrome that causes both conjunctivitis and pharyngitis, producing fever and sore throat along with conjunctivitis.
2. Acute hemorrhagic conjunctivitis
A rare type of conjunctivitis that is highly contagious and can cause worldwide epidemics. Its symptoms are sudden in onset.
3. Herpetic keratoconjunctivitis
A type of conjunctivitis caused by an infection with herpes simplex virus and may affect only one eye. Symptoms include the formation of blister-like lesions on the skin.
4. Rubella and rubeola (measles)
These viruses may cause conjunctivitis, usually accompanied by a fever, rash, and cough.
Medical Treatment for Conjunctivitis
Treatment options for conjunctivitis depend on its cause.
Antibiotic eye drops or ointments can be used to treat the underlying bacterial infection. The symptoms may subside after 3–4 days of treatment. It is important to complete the prescribed course of antibiotics to prevent a recurrence.
Antibiotics are not effective for viral conjunctivitis. The viral infection will usually resolve on its own after running its course for 2–3 weeks.
A cold compress or artificial tear solutions may provide relief from the symptoms. Severe cases may require a prescription of topical steroids to help subside inflammation.
Conjunctivitis caused by the varicella-zoster virus or herpes simplex virus requires the use of antiviral medications. The purpose of these medications is to provide symptomatic relief rather than shorten the duration of the infection.
Treating allergic conjunctivitis requires getting rid of the source of the allergy or irritation. Examples include using swimming goggles to prevent irritation from the chlorine in pool water and avoiding contact with animals if you are allergic.
Over-the-counter or prescription eye drops may provide comfort. In severe cases, the doctor may prescribe eye drops containing antihistamines or steroids. (6)
The treatment for conjunctivitis depends on its underlying cause, which warrants the need for a thorough diagnosis.
- The doctor will review your medical history, conduct an eye examination, and analyze the symptoms to shortlist the potential culprit.
- Bacterial, viral, and allergic conjunctivitis produce varying symptoms along with redness and swelling in the eye. These symptoms may help point the doctor toward the potential cause.
- Sometimes, the condition may not have any distinguishing symptoms, in which case additional tests may be required for a conclusive diagnosis.
Your doctor may collect the discharge from the infected eye for laboratory testing. The results help in determining the cause of conjunctivitis and in providing suitable treatment.
Risk Factors for Conjunctivitis
Conjunctivitis is particularly prevalent among children but it can affect people of all ages. The following factors can make you more susceptible to this condition:
- Close contact with a person having an infectious pink eye
- Exposure to environmental or chemical irritants
- Use of contact lenses, especially improper storage or poor hygiene
- Seasonal allergies or exposure to allergens
- Sharing linens, towels, or other objects with infected individuals
When to See a Doctor
It is recommended to seek medical help if you suspect conjunctivitis and undergo treatment before the symptoms become severe. Remove your contact lenses at the first sign of eye irritation or redness.
Immediate medical attention is required if the conjunctivitis is accompanied by:
- Eye pain
- Changes in vision
- Ear infection in young children
If the swelling and redness extend beyond the conjunctiva, it means that the infection has spread to the surrounding areas and will require further treatment.
Conjunctivitis, or pink eye, is a common eye infection among adults and children, which may or may not be contagious depending on its cause.
Maintaining proper hygiene and taking precautions are the best ways to inhibit the spread of infection, both around the conjunctiva or to others. Conjunctivitis is a fairly non-serious condition, but it must be handled with care since the eyes are the most delicate organs of the body.
The choice of treatment will depend on the cause and severity of the problem but one thing remains constant: the sooner you treat the infection, the lesser the discomfort.