When swelling, or angioedema, occurs without hives, it may not respond to high dose antihistamines because the cause of the swelling may be different than what traditionally causes hives.
• Swelling without hives can be due to medications such as aspirin or other NSAID's such as ibuprofen, or ACE inhibitors, which are a class of blood pressure medication.
• Hereditary angioedema (HAE) is a rare, genetic condition that can cause swelling. It is the result of either missing or low levels of a blood protein call C1 inhibitor, or C1 inhibitor that does not function properly. When C1 inhibitor is insufficient or dysfunctional it can cause episodes of painful swelling that often occur in the face, hands, feet and genitals. It can also occur in the airways or intestines, which can be especially dangerous.
- Making the diagnosis of HAE can be difficult, and often occurs after other conditions have been ruled out.
- Although antihistamines and other medications commonly used to treat angioedema occurring with hives are not effective in treating HAE, there are other more targeted treatments available.
- Additionally, many patients with HAE will learn to recognize their triggers and the early warning signs of an episode, which can assist in avoiding attacks.