Variability of prodromal signs and symptoms associated with hereditary angioedema attacks: A literature review

Hereditary angioedema (HAE) is a rare disease caused by deficiency in the production or function of C1 inhibitor. It predisposes individuals to paroxysmal acute attacks causing painful, debilitating, disfiguring, and life-threatening angioedema. Prodromes occurring hours to days before attacks have been described in the literature; however, their significance as predictive signals of impending attacks is uncertain. Given the morbidity and mortality associated with HAE attacks and the increasing availability of therapeutic products for their treatment, identifying prodromes that accurately predict the onset of attacks could provide the basis for the development of a validated instrument to identify the onset of such attacks requiring abortive therapeutic intervention before the development of clinically significant angioedema. The aim of this study was to review the literature to identify the prodromes reported to occur with HAE attacks. A literature review of English language journal articles was performed using search terms hereditary angioedema, HAE, angioneurotic edema, prodrome, signs, and symptoms. Nineteen original English language articles that included both case reports and studies describing prodromes associated with HAE attacks were obtained. Our review indicates that there is significant variability in the expression, manifestation, prevalence, timing, and predictive reliability of the prodromes that have been described. There is considerable variability of the prodromal manifestations that may occur before or during HAE attacks. We have not found any evidence that their sensitivity and specificity for accurately predicting such attacks has been studied.