Your eyelids are very delicate and are thus easily irritated. They can react to allergens on their own, and they can display symptoms of allergens that affected another part of your body. If you're allergic to certain airborne allergens like dust or dander and they land on your eyelid, your immune system will react by sending out antibodies and chemicals like histamine to fight off the allergen. In response, your eyelids might swell up, get red or start to itch. You can also break out in eczema there. A "Dennie's line," which is an extra crease across the lower part of your eyelid, might also appear.
Other ways your eyelids might respond to a contact allergen is if you have the allergen on your hands and you rub your eyes. This is common with substances like preservatives and certain resins in nail polish, fake nails and Crazy Glue, along with perfume and the neomycin found in some ointments. If you're allergic to nickel and you use a metal eyelash curler that touches your eyelids, you could end up with a form of dermatitis, like eczema. Similarly, if you're allergic to rubber and the eyelash curler has a rubber tip, you could have an allergic reaction on your eyelid. If you have some other kind of allergic reaction to food or drugs, the histamine might cause angioedema, which happens when the deep layers of your skin swell up. The most common places for angioedema to occur are your eyelids, lips, tongue, feet and hands.
Once your doctor determines what causes skin allergies on your eyelids, you should avoid contact with that substance. Should you suffer another allergic reaction, oral antihistamines and a cool compress might help the symptoms. However, you should avoid ice packs and topical antihistamines.