Signs and symptoms preceding acute attacks of hereditary angioedema: results of three recent surveys.

In patients with hereditary angioedema (HAE), premonitory symptoms ("prodromes") may appear hours to days before attack onset. It remains to be determined if prodromes could be useful indicators for early treatment initiation. Most published reports of prodromes have been limited to case reports or small case series. The common objective of several recent survey-based studies was to collect information relevant to prodromal patterns in patients with HAE. Three separate surveys solicited prodromal data from HAE patients. Although differences in survey methodologies permit only descriptive analysis of data, responses to the surveys provide the largest compilation of observational data on this topic to date. Prodromes were reported by 82.5-95.7% of patients surveyed. In one survey, about two-thirds of subjects reported experiencing prodromes before all or most acute HAE attacks, and only 6% of subjects noted the appearance of prodromes in <10% of all attacks. The most common types of prodromal symptoms were related to skin/soft tissue and gastrointestinal tract. Most prodromes were experienced hours to days before the onset of angioedema. A large percentage of surveyed subjects indicated being able to predict an impending HAE attack all or most of the time; <10% reported being rarely or never able to predict an attack. Although insufficient to establish the clinical role of prodromal symptoms, results of these surveys provide additional data on the scope of prodromes and could stimulate further research into the potential efficacy and cost-effectiveness of HAE attack prediction and prodrome-triggered interventions.