A food allergy is a mistake of the immune system, according to Kids Health. The immune system protects the body from harmful substances, such as viruses and bacteria. During a food allergy reaction, the immune system mistakes the food as a harmful substance and attempts to fight it off. Inflammation in soft tissue is a common symptom of a food allergy. The inflammation can affect the sinuses, the lungs and any part of the body made from soft tissue, such as the eyes. Swollen eyelids are more commonly associated with hay fever or allergic conjunctivitis from airborne allergens but can occur from a food allergy.
Swollen eyelids from a food allergy are the result of histamine in the eye region. As the body fights off the proteins from the food product, the immune system produces IgE antibodies, according to MayoClinic.com. The antibodies in the blood stream cause mast cells to produce histamine. Histamine is a chemical that leads to inflammation and irritation in areas of the body made up soft tissue. Increased histamine causes more blood flow to those parts of the body, leading to swelling.
The effect of increased histamine around the eyes causes eye irritation, such as watery eyes, itchy eyes and swelling. According to Sensory Processing Disorder many food allergies symptoms can develop up to 24 hours after the food has been consumed. The delayed reaction can cause more intense symptoms and excessive eye inflammation. Other common effects are asthmatic reactions, hives and nasal congestion.
The best way to prevent and treat swollen eyes from a food allergy is to identify and avoid all known food allergens. Talk with an allergist to participate in allergy testing to diagnose the specific food allergy.
MayoClinic.com states that minor symptoms of a food allergy can be treated with antihistamines. Antihistamine blocks the body's ability to produce histamine. Because histamine is the chemical responsible for the inflammation in the eye, taking an antihistamine will reduce the swelling and irritation. Antihistamine eye drops may also be purchased to treat allergy eyes.
Swollen eyelids may not be the result of a food allergy. Conjunctivitis is an infection in the lining of the eyelid that causes severe swelling around the eyes, according to MedlinePlus. Allergic conjunctivitis is typically caused by airborne allergens and does not include the presence of bacteria or a virus. Non-allergic conjunctivitis is a more serious medical condition that does involve a virus or bacteria and needs medical intervention. Only a doctor can determine the reason for your symptoms. Do not attempt to self-diagnose or self-treat.