Allergic eye disease is one of the most common ocular surface diseases, of which allergic conjunctivitis is the most common type. According to statistics, about 5% or more of the world’s population visits the doctor for allergic eye diseases, and the proportion of allergic conjunctivitis is more than 50%. In recent years, its incidence has further increased due to factors such as pollen, eye cosmetic use, contact lens wear, and increased air pollution. Therefore, it is significant to recognize allergic conjunctivitis correctly and use medication appropriately.
Itchy eyes are a common symptom in almost all types of allergic conjunctivitis, but other symptoms such as tearing, burning sensation, and discharge lack specificity and are often easily confused with other ocular surface diseases. The clinical manifestations are signs of diffuse conjunctival congestion, edema and papillae and follicular hyperplasia, which become more severe the closer to the corner part of the eye. Patients usually have no eye pain and no significant visual impairment with normal pupils. If a family member suffers from allergies, the likelihood of it being an allergic reaction is high, and its allergens are basically the same as those of allergic rhinitis.
Allergic conjunctivitis is an allergic reaction to the conjunctiva caused by exposure to allergic antigens, which is primarily an IgE-mediated type I allergic reaction. Anyone who is genetically or somatically susceptible to specific antigens can, upon exposure to such antigens, result in tachyphylaxis or delayed allergic conjunctivitis, often accompanied by allergic rhinitis, etc. There are four main types of allergic conjunctivitis: allergic conjunctivitis (containing seasonal, perennial, and contact), giant papillary conjunctivitis, springtime keratoconjunctivitis, and atopic keratoconjunctivitis. Seasonal allergic conjunctivitis is most common in young and middle-aged people and has a rapid onset, occurring upon contact with the allergen and resolving when the allergen is removed, whereas the main difference between perennial and seasonal is the presence of allergic symptoms year-round. Contact allergic conjunctivitis has a clear history of exposure, such as medication or cosmetic exposure. Macrophthalmic conjunctivitis often has a history of contact lens (corneal contact lens) wear. Springtime keratoconjunctivitis is most often seen in pediatric patients and often occurs or worsens in the spring and summer. Atopic conjunctivitis is most often seen in middle-aged men and often has a history of mild allergy early in life. Some springtime keratoconjunctivitis and atopic conjunctivitis can produce serious corneal complications and even compromise vision.
Many allergic conjunctivitis are self-limiting, so the main goal of treatment is to reduce symptoms and avoid sequelae. Allergen removal is the most effective treatment, and contact with possible allergens should be avoided as much as possible, such as paying attention to mattress hygiene, avoiding exposure to pollen, stopping wearing contact lenses, and maintaining indoor air circulation. In addition to oral anti-inflammatory drugs, topical antihistamine drops can be used to achieve satisfactory results, and mast cell stabilizer – sodium cromoglycate drops (e.g. Xinrunqing) can both treat and prevent allergic conjunctivitis, and is also the most commonly used drug. Glucocorticoids are usually used when other medications are ineffective, and should be used with caution under medical supervision because of their side effects. In addition, desensitization and surgery are also available.
Broadly speaking, there are 5 main types of allergic conjunctivitis.
Cushings fever conjunctivitis (also known as seasonal allergic conjunctivitis), contact allergic conjunctivitis, giant papillary conjunctivitis, spring cicatricial keratoconjunctivitis, and atopic keratoconjunctivitis. Seasonal allergic conjunctivitis is most common in young and middle-aged people and has a rapid onset, occurring upon exposure to allergens and resolving when the allergen is removed. Contact allergic conjunctivitis has a clear history of exposure, such as drug or cosmetic exposure, and resolves with avoidance of exposure. Macrophthalmic conjunctivitis often has a history of contact lens (keratocontact) wear. Spring cicatricial conjunctivitis is most often seen in adolescents and often occurs or worsens in the spring and summer. Atopic conjunctivitis is most often seen in middle-aged men and often has a history of mild allergy early in life. Some spring keratoconjunctivitis and atopic conjunctivitis can have corneal complications and even compromise vision.
Allergens are the culprit
Allergic conjunctivitis is caused by an allergic reaction of the conjunctival mucosal tissue of the eye to a specific allergen. Allergens are substances that cause allergies, medically known as allergens. These allergens enter the eye and bind to immunoglobulin E (IgE) on the mast cells of the conjunctiva, causing the mast cells to release histamines, which cause small local blood vessels to dilate and produce redness, swelling and itching. Allergens include pollen, dust, cold and humid air, dust mites, animal hair, soap, perfume, cosmetics, medications, contact lenses and their care solutions, etc. Because people’s individual constitution varies greatly, allergens vary from person to person. The most common allergen causing allergic conjunctivitis is plant pollen, and the symptoms of this allergic conjunctivitis tend to change seasonally. If the allergen is dust, dust mites or animal hair, etc., because these allergens are present year-round, the symptoms of allergy are also continuous throughout the year, and the symptoms are milder, but may also worsen with the seasons.
Typical symptoms are itchy eyes
The main manifestation of allergic conjunctivitis is itchy eyes. Unlike ordinary itching, this itch is often very intense and unbearable, hence the medical term itchy. It also manifests as a congested, edematous conjunctiva with mucus discharge, often accompanied by redness and swelling of the eyelid skin. These symptoms can be good and bad and recurrent during the allergy season, and are related to the climate and the patient’s activities. Generally, the symptoms worsen during warm, dry days. Some patients may develop nasal allergy symptoms in addition to eye discomfort, a condition also clinically known as allergic rhinitis conjunctivitis.
Allergic conjunctivitis
As with all allergic diseases, allergic conjunctivitis occurs when the conjunctival mucosal tissue of the eye comes into contact with an allergen in the form of inflammation of the conjunctiva. According to statistics, about 1/5 of patients in ophthalmology clinics suffer from allergic eye diseases, of which allergic conjunctivitis accounts for about 50%, which shows that allergic conjunctivitis is one of the most common diseases in ophthalmology.
The allergens that cause allergic conjunctivitis are mostly pollen, dust, cold and wet air, dust mites, animal hair and other substances that can easily enter the eye, followed by perfumes, cosmetics, drugs, contact lenses and their care solutions that are often close to the eye, and these allergens enter the eye and lead to the release of histamine and other allergenic factors from the conjunctival mast cells, which in turn cause local capillary dilation, thus These allergens cause the local capillaries to dilate, resulting in redness, swelling and itchiness in the eyes.
In addition, the conjunctiva is congested and edematous, with mucus discharge, and the skin of the eyelid is red and swollen, and the closer to the corner of the eye, the more severe the situation is. The symptoms can change well with the seasons and recur, which means that in addition to the patient’s allergic constitution, climate change and the patient’s activities are important factors in the onset of the disease. Generally speaking, the symptoms are aggravated on warm, dry, flowery days, and some patients may have nasal allergy symptoms in addition to eye discomfort, which is also clinically known as allergic rhinitis conjunctivitis.
Children are not yet mature, so the mucous membrane of the conjunctiva is extremely permeable, which makes them a natural candidate for allergic conjunctivitis, while adults with allergic conjunctivitis mostly have a history of allergies in childhood, and because their symptoms such as tearing, burning sensation, and discharge are similar to other ocular surface diseases, they are easily misdiagnosed. Therefore, we would like to remind you that if your child rubs their eyes a lot or blinks frequently at any given time, they may be suffering from allergic conjunctivitis, and ordinary anti-inflammatory eye drops will not help at all, or even lead to other eye diseases due to long-term wrong treatment.
Allergic conjunctivitis treatment should pay attention to daily protection
If allergens cannot be identified at the moment, then, first of all, it is important to improve the living environment, especially the air quality or indoor temperature, so that the influence of allergens can be reduced. Second, pay attention to nutrition and exercise, regularity of life and rest, and strengthening physical fitness. Because the improvement of physical health can make the body’s potential to fight against allergy attacks increase, and reduce and slow down allergy attacks. Again, local cold compresses or ice packs can be applied to the eyes to reduce discomfort, artificial tears can be used to spot the eyes locally, and rinsing can also be used to significantly reduce the concentration of allergens and inflammation-causing factors and improve symptoms.
Medication mainly includes the use of anti-allergic eye drops such as sodium cromoglycate and Rimex. If the symptoms are not relieved after treatment, glucocorticoid eye drops can be used for a short period of time (commonly used in clinical practice are imported drugs such as Flomax eye drops, Bactrim eye drops, and domestic drugs such as 0.5% cortisone eye drops). In case of combined ocular bacterial infection, topical antibiotics can be used. It should be noted that drug anti-allergy treatment can only control allergy symptoms, but it is difficult to completely cure allergic conjunctivitis, which is one of the reasons why allergic conjunctivitis remains untreated for a long time. Currently, we are using cryotherapy with anti-allergy medication drops to achieve better results.
Classification of allergic conjunctivitis
There are 4 main types of allergic conjunctivitis: allergic conjunctiva (including seasonal, perennial, and contact), giant papillary conjunctivitis, springtime keratoconjunctivitis, and atopic keratoconjunctivitis. Seasonal allergic conjunctivitis is most common in young and middle-aged people and has a rapid onset, occurring upon contact with the allergen and resolving when the allergen is removed, whereas the main difference between perennial and seasonal is the presence of allergic symptoms year-round. Contact allergic conjunctivitis has a clear history of exposure, such as medication or cosmetic exposure. Macrophthalmic conjunctivitis often has a history of contact lens (corneal contact lens) wear. Springtime keratoconjunctivitis is most often seen in pediatric patients and often occurs or worsens in the spring and summer. Atopic conjunctivitis is most often seen in middle-aged men and often has a history of mild allergy early in life. Some springtime keratoconjunctivitis and atopic conjunctivitis can produce serious corneal complications and even compromise vision.
Prevention and treatment of allergic conjunctivitis
However, most allergic conjunctivitis does not necessarily identify the exact allergen, or the allergen type is complex and difficult to identify, and the eye is always unlikely to This is the fundamental reason why allergic conjunctivitis is recurrent and not easily cured. This is the root cause of allergic conjunctivitis.