About Allergic Conjunctivitis
Your quick reference about allergic conjunctivitis and other allergy related conditions. Learn about the condition, the usual triggers that cause symptoms, available treatment options, and specific cautions you need to be aware of.
About 20% of Americans suffer from allergy symptoms and one of the most common places to experience symptoms are within the eyes. Eyesight is so important to people that they often are highly concerned when symptoms of allergies manifest in the eyes. Thankfully it should be noted that allergies are rarely ever are serious enough to threaten eyesight, but they certainly can make a person miserable!
One specific allergic condition relating to the eyes is allergic conjunctivitis, also known as seasonal allergic conjunctivitis and allergic rhinoconjunctivitis. Conjunctivitis means an inflammation of the conjunctiva, which is the mucous membrane covering the front of the eye and the inner part of the eyelid. Therefore, this condition is one in which the conjunctiva of the eye becomes inflamed as a result of an allergic reaction to a trigger.
The reason the conjunctiva can be a particular target of allergies is a result of the mast cells within the conjunctiva. Mast cells are found within connective tissues and play a large role in allergic responses, as when allergen molecules lock onto immunoglobulin E (IgE) antibodies, it is the mast cells that the IgE antibodies then attach to causing the release of histamine. Symptoms of allergic conjunctivitis include swollen, red, itchy and watery eyes along with blurred vision and discomfort.
Children in particular may develop a specific form of conjunctivitis known as vernal kerato-conjunctivitis. This condition is characterized by the cobblestone appearance of the conjunctiva under the eyelids. Other symptoms of this form of allergic conjunctivitis include sensitivity to light and excessive itching. Vernal kerato-conjunctivitis is usually seasonal, but may last year-round and it often is outgrown after puberty. Some children will continue to suffer from it long-term and some adults may develop the condition. Males are more likely to suffer from the illness.
Triggers of This Condition
When we say “triggers,“ we refer to substances that usually instigate an allergy attack. Common triggers of allergic conjunctivitis include pollens (grass, weed, and tree) which may be a seasonal problem depending on your geographic location. Weed pollens are usually potent in the summer and the beginning of fall, whereas grass and tree pollens tend to do the most damage in the spring and well into the summer. There are triggers that occur year round, however, and these would include: cosmetics, cigarette smoke, animal dander, house dust and dust mites, fungus spores, and mold.
Whether an episode of allergic conjunctivitis is seasonal in nature or a year-round problem, the first line of defense is to avoid your triggers to the extent that it is possible. As medications can be costly and not without side-effects, and whereas they may not even be fully effective, avoidance of triggers is a person’s best bet for maintaining his or her health and remaining allergy free. If a person’s allergic conjunctivitis is triggered by cat dander for example, the best course of action would be to avoid cats whenever possible. Similarly, if spring pollens cause significant discomfort then spring may be a time to avoid long outdoors walks or gardening.
It can be frustrating or even impossible to avoid allergens though, so the next option for sufferers of allergic conjunctivitis is to use an anti-histamine. Anti-histamines are generally very effective as they act on cells which contain histamine receptors. Anti-histamines have a molecular structure that resembles that of histamines and therefore are able to block histamine from reaching its normal receptors. When the histamine can’t get to the normal receptors the chain of occurrences that makes up the allergic reaction is interrupted. Anti-histamines work best if taken before symptoms have even appeared, so they are best used if you expect to have a reaction and take them preventatively.
There are side effects to using anti-histamines, the most significant of which is drowsiness. This can be a concern if you are trying to work or if you need to drive a car, but it can actually be helpful if you are in need of a good night’s sleep. The drowsy effect will most likely be heightened if you take an anti-histamine in conjunction with alcohol or certain other medications, so it is very important to talk with your pharmacist or medical doctor before taking this medication.
Anti-histamines can also produce anticholinergic effects including heart palpitations, dry mouth, constipation, urine retention, and anxiety. This will particularly be problematic for patients who are taking other anticholinergic medications such as Levsin, Bentyl or Donnatal. Individuals with high blood pressure, thyroid disease, or heart disease should always consult their physicians before taking antihistamine medications, even over-the-counter ones.
Another concern with anti-histamines is that your body may develop a tolerance for this medicine and therefore its effectiveness may not be as strong the more often you use it. If you note such a tolerance you may need to see your doctor for a different type of anti-histamine prescription or ask your pharmacist about using a different brand of anti-histamine that utilizes a different class of medication.
To specifically target the allergic reactions seen in allergic conjunctivitis, a person may want to consider topical treatment applied directly to the eye. There are several types of eye drops or ointments on the market that may be appropriate depending on the severity of symptoms and a person’s medical history. Such medicines may be based on cromolyn sodium mixtures, lodoxamide tromethamine or olopatadine hydrochloride, non-steroidal anti-inflammatories or others. It is wise to always seek the opinion of your physician before applying any such treatment method. In severe cases your doctor is likely to refer you to an ophthalmologist (eye specialist) to consider treatment via topical steroid. Topical steroids can be very effective but their use is associated with the development of infections, cataracts and glaucoma. Clearly such outcomes are to be avoided if at all possible and therefore topical steroid treatment must be used with great caution.
Allergic conjunctivitis is a painful and irritating condition, but not a debilitating one. Allergic triggers of conjunctivitis such as pollen, pet dander, or certain skin or beauty products should be avoided if at all possible. If avoidance is difficult or extremely undesirable then sufferers of the condition should consult an eye specialist or physician to consider their treatment options. Over-the-counter antihistamines may be appropriate, but in severe cases stronger medication, such as topical steroids, may be needed. With appropriate treatment and avoidance techniques, especially in combination, the effects of allergic conjunctivitis should be minimized to allow the sufferer to live a normal and enjoyable life.click here to learn more about allergy conditions such as allergic conjunctivitis