Hereditary angioedema with normal C4 and low or absent C1 inhibitor function
Question:
9/17/2019
I have a 23 year-old woman, with witnessed AE without hives. Her mother also has AE. The patient has responded well to Firazyr, however I would like to place her on a controller. Her insurance will not cover her because the C4 is normal, yet her c1 esterase function is 0% and 2%. Is the C4 level really essential for the diagnosis? Is there literature that will help me?
Answer:
The diagnosis of hereditary angioedema is confirmed by the presence of a low serum C4 and absent or greatly reduced C1 inhibitor level or function. It has been noted that in a few patients, C4 and C2 levels normalize in the absence of symptoms.
Please review: Arch Intern Med. 2001;161(20):2417-2429.
I hope this information is of help to you and your patient.
Regards,
Eric Macy, MD, MS, FAAAAI