Disease Description (Causes and Symptoms)
- Definition: Allergic conjunctivitis is a condition in which an allergic reaction occurs in the conjunctiva (the mucous membrane covering the whites of the eyes and the inner surface of the eyelids), causing inflammation and discomfort.
- Causes and pathophysiology: Allergens such as pollen, house dust mites, and animal dander stimulate mast cells in the conjunctiva, causing the release of mediators such as histamine. It manifests as an immediate-type hypersensitivity reaction (e.g., seasonal or perennial) or a delayed-type hypersensitivity reaction (e.g., contact-related). It is often accompanied by atopic disease, asthma, or allergic rhinitis.
- Main symptoms: Severe itching (characteristic), conjunctival hyperemia (redness), watery or viscous discharge (thin, watery discharge or mucus-like, jelly-like material), chemosis, temporary decreased vision (in severe cases when the cornea is involved), and papillae on the inner surface of the eyelids (papillary hypertrophy), especially in vernal or atopic forms. Symptoms may recur seasonally or persistently.
Treatment (Standard Treatment · Medications · Procedures/Surgery · Self-Care and Precautions)
- General principles
- Avoiding allergens (minimizing exposure to causative substances) and relieving symptoms are the foundations of treatment.
- Mild cases often improve with nonpharmacologic measures and topical medications. Specialist care (ophthalmology or allergy/internal medicine) is needed for severe or refractory cases.
- Pharmacologic treatment
- Topical ophthalmic antihistamines/anti-inflammatory agents: olopatadine, ketotifen, azelastine, etc. — agents with both immediate effects and long-term preventive effects (dual action) are commonly used.
- Maintenance and prevention: mast cell stabilizers such as cromolyn and lodoxamide (it takes time for their effects to begin).
- Lubricant eye drops: help relieve irritation and dilute allergens.
- Oral antihistamines: used when runny nose, sneezing, or systemic allergic symptoms are also present (e.g., cetirizine, loratadine).
- Ophthalmic steroids: used short-term, under a doctor's direction, when there is severe redness, papillary hypertrophy, or corneal involvement. Because of the possibility of complications (increased intraocular pressure and cataracts), management and monitoring by an ophthalmologist are necessary. Agents with a lower risk of causing elevated intraocular pressure (e.g., loteprednol) may be selected.
- Immunomodulators (steroid alternatives or long-term treatment): ophthalmic cyclosporine and topical tacrolimus (eyelid ointment) may be considered for chronic or severe vernal/atopic conjunctivitis.
- Systemic treatment/immunotherapy: For a confirmed seasonal cause, immunotherapy directed at a single antigen (subcutaneous or sublingual immunotherapy) may be considered (consult an allergy specialist).
- Nonpharmacologic/lifestyle management
- Apply cold compresses several times a day for 5–10 minutes to relieve itching and swelling.
- Do not rub the eyes (rubbing worsens symptoms and increases the risk of secondary infection).
- Stop wearing contact lenses until symptoms improve and maintain meticulous lens hygiene.
- Improve the indoor environment: use HEPA filters, wash bedding and dry it at high temperatures, manage pets, and avoid smoking and exhaust fumes.
- Precautions and risk of complications
- Long-term use of ophthalmic steroids increases the risk of elevated intraocular pressure (glaucoma), cataracts, and local infection — follow-up examinations by an ophthalmologist are necessary.
- In severe cases, corneal ulcers, scarring, and decreased vision may occur (particularly requiring caution in vernal and atopic forms).
- Long-term use of anti-redness eye drops may cause rebound redness, so they should be used only for a short period.
- Procedures/Surgery
- Most cases are managed with medication and conservative treatment. In rare cases involving severe papillary hypertrophy or corneal damage, specialized treatment (short-term intensive steroid therapy or ophthalmic procedures/surgical treatment) requires individual evaluation.
Checklist Before an Outpatient Visit (Including Items to Prepare, Records to Bring, and Example Questions)
- Items to prepare (recommended to bring)
- A list of all medications currently being taken (including eye drops), with the medication name, dosage, and administration times.
- Previous allergy test results (skin prick test, blood-specific IgE, etc.) and previous ophthalmic examination findings (intraocular pressure, corneal examinations, etc.).
- Symptom diary: when symptoms began, time of day (day/night), relationship to season and location (home/work/outdoors), and suspected triggers (pollen, dust, animals, etc.).
- Photos (such as eye redness or discharge), or images taken when symptoms were severe, may be helpful.
- Whether contact lenses are worn, the type of lenses, and wearing habits.
- Example of a brief record before an outpatient visit
- Symptoms (itching/pain/eye discharge/vision changes) and severity (1–10), start date, aggravating factors, relieving factors, and treatments previously tried and their effects.
- Key information to provide to the doctor during the visit
- Whether there are accompanying conditions (allergic rhinitis, atopic dermatitis, asthma, etc.), family history (allergies), and occupation (potential allergen exposure).
- Test preparation
- If necessary, intraocular pressure measurement, slit-lamp examination, conjunctival discharge testing (bacterial culture), and allergy testing (skin testing or blood-specific IgE) may be scheduled.
Examples of General Questions to Ask the Doctor
- "What are the expected effects and common side effects of this medication (eye drops)?"
- "Do I need steroid eye drops? How long will I need to use them, and what follow-up tests will be required?"
- "If my symptoms recur frequently, do I need immunotherapy (allergen immunotherapy)? What are the indications?"
- "When is it okay to start wearing contact lenses again?"
- "What changes to my living environment are most likely to improve my symptoms?"
Examples of Disease-Specific Questions
- "What tests or diagnostic criteria can distinguish whether my symptoms are seasonal (vernal) or atopic/chronic?"
- "If I need to use steroid eye drops long-term, how will the risks of increased intraocular pressure and cataracts be monitored? Could cyclosporine or tacrolimus be considered as steroid alternatives?"