Swollen and itchy eyes may be related to allergic conjunctivitis, mosquito bites, contact dermatitis and other causes. 1. Allergic conjunctivitis: patients with allergies to animal fur, pollen and other external allergens produce an allergic reaction, the patient may appear bulbar conjunctival edema, itchy eyes and other uncomfortable symptoms. 2. Mosquito bites: mosquito bites patients eyelid skin, can cause local inflammatory reaction, resulting in local redness, swelling, itching and other symptoms. 3. Contact dermatitis: If the eyelid area is exposed to eye cream containing allergenic substances, it can cause the patient’s body to undergo abnormal immunity, which can cause the patient’s local skin redness, swelling, itching and other uncomfortable symptoms. It is recommended that patients with swollen and itchy eyes consult a hospital in a timely manner to clarify the cause of the disease and to be treated under the guidance of a doctor.