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Conjunctivitis

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Conjunctivitis is the medical term for inflammation of the conjunctiva. The conjunctiva is a thin, clear layer of tissue. It covers the white surface of the eye, known as the sclera. It also lines the inner surface of the eyelids. When this tissue becomes inflamed, the eye appears pink or reddish.

Bloodshot eye
Bloodshot eye

This condition can affect one eye or both eyes. People often experience symptoms like burning, itching, or a scratchy sensation. Some individuals may also notice increased tearing or find their eyelids stuck shut in the morning due to discharge.

There are several distinct mechanisms that cause this inflammation. In viral conjunctivitis, viruses infect the tissue. This often occurs alongside other respiratory issues, such as a common cold or a sore throat.

Conjunctivitis disease
Conjunctivitis disease

In bacterial conjunctivitis, bacteria like Staphylococcus or Streptococcus cause the irritation. This typically results in a rapid onset of redness and a sticky, opaque discharge. Allergic conjunctivitis is an immune response. It happens when the body reacts to allergens like pollen, animal hair, or dust mites. This reaction causes mast cells to release histamine. The release of histamine leads to vasodilation, which is the widening of small blood vessels. This process causes the characteristic redness and swelling.

Allergicconjunctivitis
Allergicconjunctivitis

Doctors classify conjunctivitis based on its cause or the area it involves. The causes include viruses, bacteria, allergies, chemicals, or autoimmune responses. It can also be classified by how much of the eye is affected. For example, blepharoconjunctivitis involves both the conjunctiva and the eyelids. Keratoconjunctivitis occurs when the cornea, the clear front part of the eye, is also inflamed. If both the eyelids and the cornea are involved, it is called blepharokeratoconjunctivitis.

Membranous conjunctivitis
Membranous conjunctivitis

Some bacterial infections can even cause the formation of membranes. These are layers of inflammatory cells and fluids that adhere to the conjunctiva.

Different groups of people experience different types of conjunctivitis. In adults, viruses are the most frequent infectious cause, accounting for approximately 80% of cases. Adenoviruses are responsible for 65% to 90% of these viral instances. However, the pattern changes for children. In children, bacteria are the predominant cause, responsible for about 70% of cases. There is also a specific type called neonatal conjunctivitis. This affects newborns and is caused by different bacteria than common adult cases.

Chlamydial-conjunctivitis
Chlamydial-conjunctivitis

Diagnosing the exact cause is important for choosing the right treatment. Doctors often rely on observing signs and symptoms. They may use a slit lamp, which is a specialized microscope, to improve diagnostic accuracy. They typically examine the palpebral conjunctiva, which covers the inner eyelids, more closely than the bulbal conjunctiva. If a bacterial infection is suspected, a doctor might use a swab to collect a sample of the discharge.

Procedure of conjunctival swabs
Procedure of conjunctival swabs

This sample can be sent for a culture to identify the specific germ. For allergies, a patch test might be used to find the specific trigger.

Treatment strategies vary depending on the underlying cause. Most viral cases have no specific treatment and must resolve on their own. Bacterial infections can often be treated with antibiotics to shorten the illness. However, certain infections, such as those caused by gonorrhea or chlamydia, require specific medical attention. Allergic conjunctivitis is often managed with antihistamines or mast cell inhibitor eye drops. Chemical conjunctivitis, caused by acidic or alkaline substances, requires flushing the eye until the pH reaches a safe range of 6 to 8.

Conjunctivitis is a significant health issue in the United States. Between three and six million people suffer from acute conjunctivitis every year. Most cases typically resolve within one to two weeks. While most cases are not dangerous, some symptoms require urgent care. If a person experiences sudden visual loss, significant pain, or extreme sensitivity to light, they need an ophthalmologist. These signs might indicate more serious conditions like glaucoma, uveitis, or keratitis. Understanding the cause helps ensure the eyes heal properly and safely.

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🖼️ Images & Media (7)
File:Bloodshot eye.jpg
Bloodshot eye.jpg
File:Conjunctivitis disease.jpg
Conjunctivitis disease.jpg
File:Allergicconjunctivitis.jpg
Allergicconjunctivitis.jpg
File:Swollen eye with conjunctivitis.jpg
Swollen eye with conjunctivitis.jpg
File:Membranous conjunctivitis.jpg
Membranous conjunctivitis.jpg
File:Chlamydial-conjunctivitis.jpg
Chlamydial-conjunctivitis.jpg
File:Procedure of conjunctival swabs.jpg
Procedure of conjunctival swabs.jpg
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