Hereditary Angioedema Type II: First Presentation in Adulthood with Recurrent Severe Abdominal Pain

Hereditary angioedema presented as isolated ascending and transverse colon swelling mimicking acute abdomen

Hereditary angioedema (HAE) is a rare autosomal dominant condition characterized by C1-INH gene mutations, leading to recurrent angioedema episodes affecting various body parts, including the gastrointestinal tract. This case report describes a 24-year-old female presenting with symptoms mimicking an acute abdomen, characterized by severe abdominal cramps, anorexia, and diarrhea, with a significant past medical history of angioedema flares and emergency intubation for asphyxiation at age 11. Despite initial treatment with antihistamines showing no improvement, her symptoms spontaneously resolved. Further investigation revealed low complement C4 levels and reduced C1-INH function, confirming HAE with an unusual isolated involvement of the ascending and transverse colon. This case underscores the importance of considering HAE in patients presenting with acute abdominal symptoms, especially with a history suggestive of angioedema. It highlights the need for emergency physicians and gastroenterologists to be aware of HAE's clinical manifestations to avoid misdiagnosis and unnecessary interventions. Moreover, the case emphasizes the significance of patient education on recognizing symptoms and seeking timely medical attention to prevent severe complications. This report adds to the existing literature by detailing an uncommon presentation of HAE, aiming to enhance early diagnosis and management of this potentially life-threatening condition.

Repeated attacks of hereditary angioedema in pediatric female

A 16-year-old female presented to an outpatient clinic with a 13-year history of recurrent episodes of abdominal pain, vomiting and mild cutaneous swelling, either spontaneously or following minor trauma. The episodes occurred every 1-2 months. There was no family history of a similar complaint or hereditary angio-oedema (HAE). At the age of 16, evaluation confirmed the diagnosis of HAE type II, characterised by low C4 levels and reduced C1 esterase inhibitor function. The patient was prescribed tranexamic acid 1 g twice daily as well as C1 esterase inhibitor used as rescue medication during symptomatic episodes. This case report emphasises the importance of considering a diagnosis of HAE in patients with recurrent, unexplained abdominal pain, even in the absence of a positive family history of HAE.Abbreviations: ANA Antinuclear antibodies; C1-INH C1-inhibitor; CBC Complete blood count; FMF Familial Mediterranean fever; HAE Hereditary angioedema; IBD Inflammatory bowel diseases; SDP Solvent detergent-treated plasma; SLE Lupus erythematosus.

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.

Using an extended treatment regimen of lanadelumab in the prophylaxis of hereditary angioedema: a single-centre experience

Aim

To explore and compare the efficacy of standard (300 mg every 2 weeks) and extended (300 mg every 4 weeks) dosing regimens of lanadelumab for long-term prophylaxis of hereditary angioedema (HAE).

Methods

We conducted a retrospective chart review of all patients with HAE on lanadelumab, which identified a total of 9 patients: 5 females and 4 males. The median age of patients was 31 years (IQR 20.7). The mean number of attacks per month before starting lanadelumab was 5.9 (SD 6.3). Patients were started on 300 mg of lanadelumab subcutaneously, every 2 weeks (standard group, n = 5) or every 4 weeks (extended group, n = 4).

Results

We observed a statistically significant improvement in the number of angioedema attacks per month in all 9 patients (p = 0.007). Five out of 9 patients (56%) achieved complete remission from attacks after starting lanadelumab. The effect of lanadelumab on number of angioedema attacks was significant in both groups; extended group (p = 0.03) and standard group (p = 0.01).

Conclusion

Lanadelumab is a safe and effective agent for long-term prophylaxis of HAE. An extended dosing regimen was equally effective as prophylaxis compared to a standard regimen. Further studies are needed to compare the 2 regimens in a larger patient group.

Recurrent and acute abdominal pain as the main clinical manifestation in patients with hereditary angioedema

Background: Hereditary angioedema (HAE) is a rare disease that often leads to misdiagnosis. The delay of diagnosis is > 10 years in China. Recurrent and acute abdominal pain is one of the common symptoms of HAE. Because of the high misdiagnosis rate, it usually results in unnecessary surgical procedures. This study focused on the clinical symptoms and management of HAE-related abdominal attacks in Chinese patients to provide some new insight for the emergency department (ED) physicians and gastroenterologists. Methods: A Web-based survey was conducted among 107 patients with HAE from 94 unrelated families. Detailed questions with respect to the abdominal attacks were asked, including the frequency, symptoms, and duration before and after confirmed diagnosis. The demographic characteristics, diagnosis process, and treatment outcomes were also included. Results: Approximately 70% of the patients with HAE presented with abdominal symptoms during the onset of edema, mostly characterized by pain (94.8%), nausea (83.1%), vomiting (83.1%), diarrhea (59.7%), and constipation (23.4%). The patients were easily misdiagnosed as having gastroenteritis (35.1%) and appendicitis (10.4%), and 24.7% of them received unnecessary appendectomy or laparotomy. Danazol, a widely used drug for long-term prophylaxis of HAE in China, can reduce the attack frequency and alleviate the abdominal symptoms, but the adverse effects are also significant and more severe in women. Conclusions: Abdominal symptoms are common and important clinical features of HAE but are easily confused with other gastrointestinal diseases. ED physicians and gastroenterologists should consider HAE when patients experience recurrent and unexplained abdominal pain. Proper medical treatment should be administered in a timely manner if an HAE diagnosis is confirmed and efforts are required to increase access in China to medications both for on-demand treatment and long-term prophylaxis.