I Have Swelling! Does This Mean I’m Allergic to Something?

Swelling, known by the medical term angioedema, is very common and may or may not represent an allergy. Approximately 10-20% of the population may experience an episode of angioedema in their lifetime. Some have swelling associated with hives and others have swelling alone. Angioedema tends to affect the areas with thin skin – the eyes, ears, and lips, but can also impact the face, hands, and feet. Allergists review your history and consider food allergy, drug allergy, and genetic causes and may perform testing if indicated. Like urticaria (hives), there is often no cause identified for angioedema.

One of the most common causes of angioedema is medications. Certain blood pressure medications may cause swelling as a side effect. Angiotensin-converting enzyme inhibitors such as lisinopril can cause swelling in about 0.1-0.7% of patients. The swelling can recur for months even after the medication is stopped. It is important to talk to your doctor about the plan for blood pressure control if you have possibly experienced swelling as a side effect of one of your medications.

Food allergy causes of angioedema tend to be fairly obvious. Swelling associated with foods, in most cases, occurs within 2 hours but can take as long as 6-8 hours to develop depending on the food. If swelling occurs regardless of what is eaten and there is no consistent food involved in every reaction, it is unlikely due to food allergy. Board certified allergists rarely uncover a food allergy that was not already known to the patient or apparent by the history.

There are also rare, genetic forms of angioedema that allergists are trained to identify and evaluate. Hereditary angioedema is characterized by recurrent episodes of severe swelling that can be life threatening. This kind of swelling is not common and impacts about one in 50,000 to 150,000 worldwide. There is effective treatment for hereditary angioedema, which is part of why it is important to have an evaluation with a board certified allergist if you have recurrent swelling.

The most common form of angioedema is idiopathic, meaning there is no known cause. Idiopathic angioedema can be frustrating since there is no trigger to avoid. Many patients experience a prodromal sensation with tingling and burning before the swelling begins, which can allow time to take medication that can prevent the worst of the swelling. Antihistamines are used to prevent and treat idiopathic angioedema. Steroids, such as prednisone, can treat acute symptoms, but the swelling can recur when they are stopped. It is important to talk with your allergist about the long-term management plan for future episodes.

Swelling is a symptom I evaluate a few times a week. At your allergy appointment, we’ll figure out if there is a cause and come up with a plan together so that you can get on with your life!