Hereditary angioedema: a disease seldom diagnosed by pediatricians.

Objectives: To describe the hereditary angioedema to improve awareness of this condition and reduce diagnostic delay.

Data Sources: Relevant articles in the MEDLINE database through PubMed.

Data Synthesis: Hereditary angioedema is rare and has an autosomal dominant pattern of inheritance. Its onset occurs mainly in childhood, but there is an important delay in the diagnosis. In the most frequent phenotype, there is a quantitative and/or functional deficiency in the C1esterase inhibitor protein, which regulates the activation of the complement, contact and fibrinolysis systems with greater formation of bradykinin, the main mediator of angioedema. There is a third type, the hereditary angioedema with a normal C1 inhibitor level, which is rare in children. Clinical manifestations are characterized by recurrent angioedema attacks, mainly in the extremities, abdomen and upper airways, which can progress to asphyxia and death. The main triggers are mechanical trauma, infections and stress. The diagnosis is attained by patient clinical picture and decreased serum levels of C4 and C1esterase inhibitor or its function. In hereditary angioedema with a normal C1 inhibitor, there is no change in these parameters, thus requiring a genetic study. Treatment is based on the use of attack medications and long and short-term prophylaxis.

Conclusions: Hereditary angioedema is little known by pediatricians due to the significant delay in diagnosis of this condition, whose onset usually begins in childhood. The presence of recurrent angioedema that does not respond to treatment with antihistamines, corticosteroids and adrenaline should increase the diagnostic suspicion.