Eyelid swelling is uncomfortable and sometimes painful. A swollen eyelid is usually caused by an infection, a blockage that leads to an infection or an allergic reaction. Depending on the cause of the swelling and the severity of the symptoms, a doctor may need to be seen.
Dacryocystitis is caused by a blockage of the lacrimal sac that is found on the inside corner of the eye, by the nose. When it becomes blocked, bacteria in the sac cause an infection. Infants frequently get dacryocystitis because the lacrimal sac clogs easily. The infection affects one eye and appears as a bump that is red and swollen. Symptoms include swelling of the eyelid, discharge, redness and excessive tearing.
Another cause of a swollen eyelid is blepharitis. Blepharitis is caused by a bacterial or viral infection, an allergic reaction or sometimes an unknown reason. Symptoms of blepharitis include swelling around the edges of the eyelid, redness, excess tears, a feeling there is something in the eye and itching.
Angioedema occurs when tissues just under the skin swell. The two types of angioedema are: hereditary angioedema (HAE) and acquired angioedema (AAE). Angioedema usually affects the eyes and lips, but it also can affect the throat, feet and hands. An allergic reaction to medication or food is the typical trigger for angioedema. Nuts, blood pressure medicine, shellfish, ibuprofen, dairy, antibiotics and aspirin are all possible triggers.
Chagas disease is a potentially life-threatening tropical parasitic infection. It's found most often in South America, Mexico and Central America, but also is present in the United States. The infection is usually passed from person to person by a triatomine bug. The two phases of Chagas are: acute, lasting a few weeks or months after infection, and chronic, which can last for lifetime, with or without symptoms. One easily recognised symptom of the acute phase is called Romaña's sign, which causes eyelid swelling near the bite of a triatomine bug or in the eye, when bug faeces came into contact with the eye.
A sty is a red bump that appears on the edge of the eyelid. A sty is caused by bacteria in the eyelash root, called the follicle. The oil glands in the eyelid become blocked, leading to a painful infection. A swollen eyelid, discharge, tearing and a crust that forms on the eyelid are the most common symptoms.