C1 inhibitor deficiency

Keywords: Hereditary angioedema

Causes

Appropriate Tests

Inherited

  • Hereditary angioedema

Complement components C3 and C4. C1 esterase inhibitor - immunological assay should be requested initially.

Functional assay should be requested if immunological assays are negative and there is a high index of clinical suspicion.

Acquired

 

  • SLE

 

  • Carcinoma, especially
    • Colorectal

 

  • Lymphoma (non-Hodgkin)