Eyes itch at night

Sometimes our eyes feel itchy, but if we rub them with our hands, they will feel much better. But for some friends, their eyes will be very itchy at night, and even rubbing them hard will not relieve the pain. In fact, this is most likely allergic conjunctivitis. Generally speaking, allergic conjunctivitis is caused by the patient's exposure to allergens. To relieve the itchy eyes caused by allergic conjunctivitis, you can use medication.

Allergic conjunctivitis, also known as allergic conjunctivitis, is a hypersensitivity reaction of the conjunctiva to external allergens. It mainly includes type I allergic reaction and type IV allergic reaction, among which allergic conjunctivitis caused by type I allergic reaction is the most common. Allergic conjunctivitis caused by type I allergic reaction is a rapid-onset type, mainly referring to allergic conjunctivitis including seasonal allergic conjunctivitis, perennial allergic conjunctivitis, giant papillary conjunctivitis, vernal keratoconjunctivitis, atopic keratoconjunctivitis, etc.; allergic conjunctivitis caused by type IV allergic reaction is a delayed-onset type, mainly including vesicular conjunctivitis.

Clinical manifestations

The most common symptom of allergic conjunctivitis is itchy eyes, which can occur in almost all patients with allergic conjunctivitis, among which vernal keratoconjunctivitis is usually the most obvious. Other symptoms include tearing, burning sensation, photophobia and increased secretions. The secretions are mostly mucous. Some more serious allergic conjunctivitis, such as vernal keratoconjunctivitis and atopic keratoconjunctivitis, can sometimes cause decreased vision.

The most common sign of allergic conjunctivitis is conjunctival hyperemia. Conjunctival papillary hyperplasia is another common sign, with papillae mostly appearing on the upper eyelid conjunctiva. The hyperplastic papillae in giant papillary conjunctivitis and vernal keratoconjunctivitis have specific morphological characteristics. Atopic keratoconjunctivitis often presents with fibrotic (scarring) changes in the conjunctiva. Conjunctival edema may also occur during seasonal allergic conjunctivitis, which is particularly common in children. The most common corneal lesions are vernal keratoconjunctivitis and atopic keratoconjunctivitis.

The purpose of treatment is to alleviate clinical symptoms and avoid sequelae, while attention should be paid to avoiding the occurrence of iatrogenic complications.

1. General treatment

Allergen avoidance is the most ideal and effective treatment. Contact with possible allergens should be avoided as much as possible. For example, remove rags and blankets from the room, pay attention to bed hygiene, use pesticides to eliminate insect mites in the room, avoid contact with grass, tree flowers, etc. during the pollen transmission season, stop wearing or replace high-quality contact lenses and care solutions. Applying cold compresses to the eyelids may provide temporary relief.

2. Medication

(1) Antihistamines Antihistamines are usually used topically. Commonly used eye drops include 0.1% Emedastine, 0.05% Levocabastine, 0.1% Olopatadine and 0.5% Ketorolac. If there are extraocular symptoms, oral medications can be used, but their effect is not as good as topical medications. Commonly used oral medications include diphenhydramine, chlorpheniramine, promethazine, etc. The combined use of antihistamines and vasoconstrictors, such as Runjianasol, can often achieve better therapeutic effects.

(2) Commonly used mast cell stabilizers include disodium chromoglycate and nedocromil. Although mast cell stabilizers are less effective than antihistamines overall, they appear to be more effective in suppressing tearing. Best used before exposure to allergens.

(3) Nonsteroidal anti-inflammatory drugs can be used in both the acute and intermittent stages of allergic diseases. They have shown certain therapeutic effects in relieving eye symptoms and signs such as itchy eyes, conjunctival congestion, and tearing. They can also reduce the dosage of hormones. Commonly used drugs include indomethacin (diclofenac sodium) and aspirin.

(4) Commonly used drugs for topical use of vasoconstrictors include epinephrine naphazoline, oxymetazoline, tetrahydrozoline, etc., which can improve eye discomfort and reduce ocular surface congestion.

(5) Glucocorticoids should only be used when other drugs are ineffective in treating severe allergic conjunctivitis, and the duration of use should not be too long to avoid complications such as cataracts, glaucoma virus infection, fungal infection, and delayed corneal epithelial healing. Commonly used ones include dexamethasone, betamethasone and fluorometholone.

(6) The main immunosuppressants are cyclosporine A and FK506. For some severe cases of vernal keratoconjunctivitis that require the use of hormones, topical application of 2% cyclosporine A can quickly control local inflammation and reduce the amount of hormones used. However, relapse is common after medication discontinuation.

3. Desensitization treatment

This method is mainly used for seasonal allergic conjunctivitis. Its therapeutic effect is often not ideal for other subtypes of allergic conjunctivitis, so it is rarely used.

4. Cryotherapy

This method is mainly used for vernal keratoconjunctivitis. Cryotherapy is often used on the upper eyelid conjunctiva, lowering the temperature to -80°C to -30°C for 30 seconds. Cryotherapy can be repeated 2 to 3 times.

5. Psychotherapy

Ocular allergic disease is an acute or chronic recurrent disease, and it is often very difficult to completely cure it. Therefore, it causes great psychological pressure on some patients. In particular, some children with vernal keratoconjunctivitis may have certain psychological disorders and should be paid attention to.