Conjunctivitis is an inflammation of the conjunctiva. It is commonly known as pink eye. The conjunctiva is the thin, transparent layer which covers the inner surface of the eyelids and covers the white part of the eye. While conjunctivitis can result from various causes, two primary types are allergic and contagious conjunctivitis.
Understanding the differences between allergic vs contagious conjunctivitis is important. It allows for effective diagnosis and management.
Allergic conjunctivitis
Allergic conjunctivitis happens when the conjunctiva becomes inflamed due to an allergic reaction. This reaction is often triggered by allergens such as pollen, pet dander, dust mites, or specific chemicals. When the allergen meets the eye, the immune system releases histamines and other chemicals, causing concerns like:
- Redness
- Itching
- Tearing
- Swelling
One prominent feature of allergic conjunctivitis is its bilateral presentation. This means both eyes are usually affected simultaneously. Symptoms tend to be more pronounced during allergy seasons or when exposed to specific triggers. Unlike contagious forms, allergic conjunctivitis does not spread from person to person.
Contagious conjunctivitis
Contagious conjunctivitis is caused by infectious agents like viruses or bacteria. The most common viral culprits include adenovirus, while bacterial strains like Staphylococcus aureus and Streptococcus pneumoniae are frequent causes. It spreads through direct contact with infected individuals, contaminated surfaces, or shared items like towels or makeup. Symptoms of contagious conjunctivitis may include:
- Redness
- Discharge (clear or coloured)
- Gritty sensation
- Crusting of eyelids, especially upon waking
Unlike allergic conjunctivitis, contagious forms can be unilateral (affecting one eye initially) but may progress to involve both eyes.
How are the two different?
- Onset and duration
Allergic conjunctivitis usually develops rapidly after exposure to allergens and may persist as long as the allergen remains present. Meanwhile, contagious conjunctivitis often has a more sudden onset and can resolve within a week or two, depending on the cause and treatment. However, there is a common misconception that allergic conjunctivitis occurs more frequently in some people than others.
For example, some may read up on why South Asian women’s health is different and assume that they are more prone to specific conditions due to compromised immunity.
- Discharge
Allergic conjunctivitis may produce clear, watery discharge, whereas contagious forms often manifest with thicker, pus-like discharge.
- Itching
Contagious conjunctivitis may cause minimal itching and is more commonly associated with discomfort, irritation, or a foreign body sensation.
Treatment and management
After understanding the differences between allergic vs contagious conjunctivitis, we come to the treatment strategies. They vary based on the type and severity of conjunctivitis. Allergic conjunctivitis often responds well to antihistamines, decongestants, and avoidance of allergens. Contagious conjunctivitis may require antiviral or antibiotic medications, along with supportive measures like warm compresses and artificial tears.
Conclusion
Proper diagnosis by a doctor is essential for appropriate treatment and prevention of complications. Also, practising good hygiene and avoiding touching the eyes prevents the spread of contagious forms.