Overview

Pink eye, medically known as conjunctivitis, is a common eye condition characterized by inflammation of the conjunctiva — the thin, transparent tissue that lines the inner surface of the eyelid and covers the white part of the eyeball. This inflammation causes the eye to appear pink or red, hence the name “pink eye.” Conjunctivitis can affect one or both eyes and occurs in people of all ages, though it is especially common in children. While most cases are mild and resolve on their own, some forms of pink eye can be highly contagious and require medical attention.

Causes

Pink eye can be caused by several different factors, including infections, allergies, and irritants. The main causes are:

• Viral infections: The most common cause, especially linked to adenovirus. Viral conjunctivitis spreads easily and is often accompanied by cold-like symptoms.
• Bacterial infections: Caused by bacteria such as Staphylococcus aureus or Streptococcus pneumoniae, leading to more intense redness, discharge, and crusting.
• Allergic reactions: Allergic conjunctivitis occurs due to pollen, dust, pet dander, or other allergens and is not contagious.
• Chemical or environmental irritants: Smoke, chlorine in swimming pools, and exposure to chemicals can irritate the eyes and cause pink eye.
• Contact lens use: Improper hygiene or overuse of contact lenses can lead to eye irritation and conjunctivitis.
• Newborn conjunctivitis: Infants can develop pink eye due to infection during childbirth, requiring prompt treatment.

Symptoms

Symptoms of pink eye can vary depending on the cause, but common signs include:

• Red or pink discoloration of the white part of the eye.
• Watery or thick discharge from the eye, sometimes causing crusting, especially in bacterial conjunctivitis.
• Itchy or gritty feeling in the eye, often more pronounced in allergic conjunctivitis.
• Swelling of the eyelids and increased tearing.
• Burning or stinging sensation in the eyes.
• Increased light sensitivity (photophobia).
• Blurry vision due to excess discharge.
• Cold-like symptoms in viral conjunctivitis, such as a runny nose or sore throat.

Diagnosis

Diagnosis of pink eye is usually made based on a physical examination and medical history:

• Clinical examination: A healthcare provider examines the eyes for redness, discharge, and swelling.
• Symptom history: Information about recent illnesses, allergies, or exposure to irritants helps identify the cause.
• Swab or culture: In certain cases, especially if the condition is severe or unresponsive to treatment, a sample of eye discharge may be taken for laboratory analysis.

Most cases are diagnosed clinically without the need for specialized tests.

Treatment

Treatment of pink eye depends on the underlying cause:

• Viral conjunctivitis: No specific treatment is required. The infection usually clears up within 7 to 14 days. Supportive care includes applying cold compresses and using artificial tears for relief.
• Bacterial conjunctivitis: Treated with antibiotic eye drops or ointments to shorten the duration of infection and reduce complications.
• Allergic conjunctivitis: Managed by avoiding allergens and using antihistamine or anti-inflammatory eye drops to control symptoms.
• Chemical or irritant conjunctivitis: Immediate flushing of the eyes with clean water is recommended, followed by medical evaluation if necessary.
• Newborn conjunctivitis: Requires prompt antibiotic treatment to prevent serious eye damage or vision loss.

General supportive measures include practicing good hygiene, avoiding touching or rubbing the eyes, and not sharing personal items like towels or makeup.

Prognosis

The prognosis for pink eye is generally excellent. Most cases, especially viral and allergic conjunctivitis, resolve on their own without long-term effects. Bacterial conjunctivitis typically responds well to antibiotic treatment within a few days.

Complications are rare but can include corneal inflammation or vision problems if left untreated, especially in newborns or individuals with weakened immune systems. Early diagnosis, proper hygiene, and appropriate treatment usually lead to a full recovery without complications. Preventing the spread of infection by washing hands frequently and avoiding close contact during the contagious period is key to controlling outbreaks, particularly in schools and daycare settings.