HAE patients have a defect in the gene that controls a blood protein known as the C1 Inhibitor. The genetic defect results in the production of either inadequate or a dysfunctional C1-Inhibitor protein. Normal C1-Inhibitor helps to regulate the interactions between certain blood vessels that assist in disease fighting, inflammation, and coagulation. Because a defective C1-Inhibitor protein cannot function correctly, a biochemical imbalance can occur which results in a production of unwanted proteins that cause small blood vessels called capillaries to release fluids into surrounding tissue, thereby causing edema.
What Causes an Attack?
Most attacks occur with no apparent reason. However, anxiety, stress, minor trauma, surgery, and illnesses like a cold or flu can be triggers. Dental procedures or any trauma to the oral cavity can make HAE patients susceptible to airway attacks. The following have been shown to increase the risk of an attack:
- Anxiety or stress
- Respiratory Illnesses
- Certain medications: specifically, ACE Inhibitors (a medication used for high blood pressure) and oral contraceptives