Dr Niranjan K Pehere, Consultant, Pediatric Ophthalmology, Strabismus and Neuro-ophthalmology, The David Brown Children’s Eye Care Centre – L V Prasad Eye Institute
What is allergic conjunctivitis?
Conjunctiva is a thin transparent film covering the white portion of the eye. Inflammation (reaction) of conjunctiva in response to some irritating element in environment or allergens is called allergic conjunctivitis. The most common allergens are dust, pollens (of grass, weed, trees), mold (spores of some of fungi) and dander (animal hair/particles of shed skin).
Allergic conjunctivitis is usually broken down into different categories and Vernal Keratoconjunctivitis is one of the severe forms of seasonal allergic conjunctivitis that affects children in particular. It usually starts in late childhood and is more common in boys than girls. It usually lasts for between 5-10 years and is rarely seen after the age of 30 and is also prevalent in tropical and temperate climates.
What are the symptoms of allergic conjunctivitis?
- Itching: Itching sensation in eye is the most common symptom of allergic conjunctivitis. Without itching it is less likely that a person is suffering from allergic conjunctivitis.
- Burning sensation
- Stringy discharge
- Puffy eye lids
- Sensitivity to light
Usually these symptoms are present in both eyes, though the severity may be different in each eye. It affects people of all ages, though seen more common in children and young adults. Sometimes, allergic conjunctivitis can be a part of generalized allergic reaction in body. Along with eye problem, patient may have:
- Running nose: This is called allergic rhino-conjuncti
- Wheezing: Asthma
- Skin rash: Urticaria (especially with mold allergy), eczema
Why do some people have this problem all through year and some have only during particular season?
Some people suffer from allergic conjunctivitis for the whole year (perennial allergic conjunctivitis). This is mostly seen in response to allergy to house dust mite, animal dander, indoor and outdoor mould spores and occasionally food or food additives. Some suffer during particular season like spring, fall, etc. This usually happens due to pollens being released in air in that season and the dry air which makes them freely float in the atmosphere. During rain, the pollens settle down, hence the patients feel symptom free.
How is allergic conjunctivitis treated?
If possible, it is best to identify the allergen and keep away from it. There are several immunological tests available to possibly indentify them, but usually patients/parents themselves can identify the cause. e.g. If one is sensitive to house dust mite, these measures may help: removing carpet, using barrier encasing of pillows and mattress, washing bedding in hot water etc. If a child is sensitive to dust, wearing glasses during play may help. Few simple measures like cleaning eyes with cold water or cold compress are generally sufficient for mild cases. But for severe cases, medication is necessary.
Common medications (eye drops) used to treat allergic conjunctivitis:
- Topical lubricants: These help flush allergens from the eye
- Antihistamines: Histamine is one of the key mediators of inflammation. This medication acts against histamine.
- Mast cell stabilizers: These medications ‘quieten’ the mast cells, which release histamine
- Steroids: These are effective in quickly relieving the symptoms, but have significant side effects as well like cataract formation, glaucoma and infections of the cornea and conjunctiva. Hence these drops (or any eye drops for that matter) must be taken under proper medical supervision only.
Why does this problem keep recurring?
The person is prone to allergic conjunctivitis if his/her body’s immune system does not react well to a particular substance in the environment. It is very difficult to change this basic tendency of the immune system permanently with medication. If the allergen is known, immunotherapy for that specific allergen may benefit some patients with persistent, severe allergic conjunctivitis. The goal of medical treatment is basically to make patient symptom free, with least possible side effects of medications and maintain good quality of life. This needs to be understood well by the patient and parents. Following preventive measures may be taken by patients with allergic conjunctivitis to reduce the symptoms:
- Try to identify the allergen and reduce exposure as much as possible
- Try to avoid rubbing eyes
- Avoid self medication
- Wash your bed linens, pillowcases, and towels in hot water and detergent to reduce allergens.
- Avoid wearing eye makeup and don't share eye makeup with anyone else.
- Never wear another person's contact lens.