Search for a rare disease
Other search option(s)
A rare disease characterized by the occurrence of transitory and recurrent subcutaneous and/or submucosal edemas resulting in swelling and/or abdominal pain due to an acquired C1 inhibitor (C1-INH) deficiency.
ORPHA:91385Classification level: Group of disorders
- Acquired C1 inhibitor deficiency
- Acquired angioneurotic edema
- Acquired bradykinine-induced angioedema
- Acquired non histamine-induced angioedema
- Prevalence: Unknown
- Inheritance: Not applicable
- Age of onset: Adult
- ICD-10: T78.3
- OMIM: 300909
- UMLS: C2931758
- MeSH: C538173
- GARD: 8605
- MedDRA: -
Prevalence is unknown.
Onset most commonly occurs after 50 years of age. Patients present with white, circumscribed nonpruritic edemas that remain for a period of 48 to 72 hours and recur with variable frequency. The edemas may involve the digestive tract resulting in a clinical picture similar to that seen in intestinal occlusion syndrome, sometimes associated with ascites and hypovolemic shock. Laryngeal edema can be life-threatening with a risk of death of 25% in the absence of appropriate treatment. Dental procedures are a triggering factor for laryngeal edema. Edemas of the face are a risk factor for laryngeal involvement.
The edemas are triggered by increased permeability of the blood vessels in response to elevated levels of bradykinin as a result of the C1-INH deficiency. Type 1 AAE (see this term) is frequently associated with lymphoproliferative syndromes and accelerated consumption of C1-INH, and with autoimmune diseases that may manifest several years after the initial episodes of angioedema. Type 2 AAE (see this term) is associated with the presence of autoantibodies to the C1-INH that neutralize C1-INH activity and are often associated with dysglobulinemia of unknown origin. AAE can also be induced by renin-angiotensin-aldosterone system blockers (RAAS-blocker-induced angioedema; see this term).
Diagnosis relies on clinical findings, measurement of C4 concentrations and on quantitative and functional analysis of C1-INH. C1q levels are low in patients with AAE but are normal in patients with hereditary angioedema (see this term).
The differential diagnosis should include intestinal occlusion syndrome, hereditary angioedema and histamine-induced angioedema (of allergenic or nonallergenic origin) generally associated with urticaria.
Management and treatment
Treatment of the associated disease should generally allow episodes to be controlled and lead to normalization of C1-INH levels. In the absence of an associated disease, the treatments used to manage the hereditary forms of angioedema may be of benefit.
The prognosis depends on the risk of developing hematological manifestations. Rituximab can be an alternative treatment in cases of AAE associated with C1-INH antibodies.