Allergic conjunctivitis in the eye

The conjunctiva is the thin membrane over the white of the eye and inside the eyelids. When it reacts to allergens such as pollen, dust mites, mould or animal dander, the eyelids may look puffy and the eyes can burn or feel gritty. Itching is a prominent presentation of allergic conjunctivitis, and nasal sneezing or congestion may occur at the same time.

Watery or stringy discharge can accompany an allergy. Thick pus, eyelids stuck together, a painful eye or symptoms starting in only one eye may suggest infection, a foreign body or another cause and deserve assessment rather than assumptions based on redness alone.

Avoid rubbing because friction can intensify swelling and itching. Wash hands, apply a clean cool compress to closed eyelids, and use preservative-free lubricating drops if suitable. After outdoor exposure, washing the face and hair and changing clothes may reduce pollen carried close to the eyes.

Stop wearing contact lenses until the eyes are comfortable and the lens wearer has ruled out a more serious problem. A pharmacist or clinician can advise on allergy eye drops or other medication; check first for a child, during pregnancy, or when another eye medicine is already being used.

Get urgent care for reduced or blurred vision, significant eye pain, marked sensitivity to light, an eye injury, chemical exposure, or a severe headache with nausea. A contact-lens wearer with a red or painful eye should remove the lenses and obtain prompt assessment because the cornea may be involved.

Book a routine review if symptoms keep returning, do not improve with sensible self-care, interfere with sleep or daily tasks, or have an uncertain trigger. Examination can separate allergy from dry eye, infection and eyelid inflammation.

Describe whether one or both eyes are affected, the type of discharge, contact-lens use, seasonal timing, nasal symptoms and any change in sight. Ask which drops are appropriate, how to use them without contaminating the bottle tip, and whether recurring symptoms justify allergy testing.