Anchoring bias in a case of recurrent abdominal pain

Hereditary Angioedema: Diagnosis, Clinical Implications, and Pathophysiology

Hereditary angioedema (HAE) is an autosomal dominant disorder caused by a mutation in the C1 esterase inhibitor gene. HAE affects 1/50,000 people worldwide. Three main types of HAE exist: type I, type II, and type III. Type I is characterized by a deficiency in C1-INH. C1-INH is important in the coagulation complement, contact systems, and fibrinolysis. Most HAE cases are type I. Type I and II HAE result from a mutation in the SERPING1 gene, which encodes C1-INH. Formally known as type III HAE is typically an estrogen-dependent or hereditary angioedema with normal C1-INH activity. Current guidelines now recommend subdividing hereditary angioedema with normal C1 esterase inhibitor gene (HAE-nl-C1-INH formerly known as HAE type III) based on underlying mutations such as in kininogen-1 (HAE-KNG1), plasminogen gene (PLG-HAE), myoferlin gene mutation (MYOF-HAE), heparan sulfate-glucosamine 3-sulfotransferase 6 (HS3ST6), mutation in Hageman factor (factor XII), and in angiopoietin-1 (HAE-ANGPT-1). The clinical presentation of HAE varies between patients, but it usually presents with nonpitting angioedema and occasionally abdominal pain. Young children are typically asymptomatic. Those affected by HAE usually present with symptoms in their early 20s. Symptoms can arise as a result of stress, infection, or trauma. Laboratory testing shows abnormal levels of C1-INH and high levels of bradykinin. C4 and D-dimer levels can also be monitored if an acute HAE attack is suspected. Acute treatment of HAE can include IV infusions of C1-INH, receptor antagonists, and kallikrein inhibitors. Short- and long-term prophylaxis can also be administered to patients with HAE. First-line therapies for long-term prophylaxis also include IV infusion of C1-INH. This review aims to thoroughly understand HAE, its clinical presentation, and how to treat it.

Consider Hereditary Angioedema in the Differential Diagnosis for Unexplained Recurring Abdominal Pain

Health care providers are likely to encounter patients with recurrent unexplained abdominal pain. Because hereditary angioedema (HAE) is a rare disease, it may not be part of the differential diagnosis, especially for patients who do not have concurrent skin swelling in addition to abdominal symptoms. Abdominal pain is very common in patients with HAE, occurring in up to 93% of patients, with recurrent abdominal pain reported in up to 80% of patients. In 49% of HAE attacks with abdominal symptoms, isolated abdominal pain was the only symptom. Other abdominal symptoms that commonly present in patients with HAE include distension, cramping, nausea, vomiting, and diarrhea. The average time from onset of symptoms to diagnosis is 6 to 23 years. Under-recognition of HAE in patients presenting with predominant gastrointestinal symptoms is a key factor contributing to the delay in diagnosis, increasing the likelihood of unnecessary or exploratory surgeries or procedures and the potential risk of related complications. HAE should be considered in the differential diagnosis for patients with unexplained abdominal pain, nausea, vomiting, and/or diarrhea who have complete resolution of symptoms between episodes. As highly effective targeted therapies for HAE exist, recognition and diagnosis of HAE in patients presenting with isolated abdominal pain may significantly improve morbidity and mortality for these individuals.