C4A and hereditary angioedema: Following triage with a dedicated rapid tool,18and due to a lack of response to antiallergic therapies (corticosteroids, antihistamines and epinephrine), the history of episodes of abdominal pain, and decreased C4 levels, HAE was suspected, for which she received intravenous (IV) plasma‐derived C1 inhibitor (plasma‐derived C1‐INH).