Pink eye, medically known as conjunctivitis, is the inflammation of the thin, transparent layer that covers the white part of the eye and the inner surface of the eyelid, called the conjunctiva. When the small blood vessels in this membrane become irritated and swollen, they become more visible, which causes the characteristic pink or reddish appearance of the eye. Understanding the distinct signs and symptoms of this common condition is the first step toward determining the best course of action.
Key Symptoms of Conjunctivitis
The most recognizable sign of conjunctivitis is the pink or red discoloration in the white part of the eye, known as hyperemia. This redness is typically accompanied by a feeling of grittiness or a foreign body sensation, as if sand or an eyelash is caught in the eye. Discomfort often includes a burning or stinging feeling.
Another common feature is the presence of discharge, which can vary in consistency and amount, sometimes leading to crusting along the lash line. This crusting is frequently noticed upon waking, sometimes making the eyelids stick together. Eyelids may also appear swollen or puffy due to the underlying inflammation.
Symptoms frequently begin in one eye and then spread to the other eye within a few days, particularly in infectious forms. Excessive tearing or watering of the eyes is also a typical response to the irritation. The precise nature of the discharge and associated symptoms can help pinpoint the underlying cause.
Identifying the Underlying Cause
Conjunctivitis is broadly classified into three primary types: viral, bacterial, and allergic, with the discharge type being a key differentiator.
Viral Conjunctivitis
Viral conjunctivitis is the most common and is frequently caused by the same viruses responsible for the common cold, such as adenovirus. This form produces a clear, thin, and watery discharge. It is often associated with other cold or flu-like symptoms, like a sore throat or runny nose.
Bacterial Conjunctivitis
Bacterial conjunctivitis is characterized by a thick, sticky, pus-like discharge that is typically yellow or green. This thicker discharge is what often causes the eyelids to be matted shut, especially after sleeping. The bacterial form is easily spread through contact with eye secretions.
Allergic Conjunctivitis
Allergic conjunctivitis is not contagious and is triggered by an immune response to common allergens like pollen, dust mites, or pet dander. The hallmark symptom is intense itching, which is often more severe than in infectious types. This type typically affects both eyes simultaneously and can be accompanied by sneezing or nasal congestion.
When to Consult a Doctor
While many cases of pink eye are mild and resolve on their own, certain “red flag” symptoms indicate the need for professional medical evaluation. Seek medical attention if you experience severe eye pain or if the discomfort goes beyond a simple gritty or irritating feeling. Any sudden changes in vision, such as blurring, or a noticeable decrease in visual acuity warrant immediate care.
Extreme sensitivity to light, known as photophobia, can also signal a more serious underlying condition. If the redness or other symptoms worsen after 24 hours, or if they persist without improvement after a few days, a healthcare provider should be consulted.
Contact lens wearers should also seek prompt medical advice if they develop any symptoms of pink eye, as they face a higher risk of developing corneal infections. A doctor should also see a newborn infant who develops symptoms of pink eye immediately, as this can indicate a serious infection acquired during birth. Individuals with a weakened immune system due to other medical conditions should also seek medical care for any signs of conjunctivitis.