Hereditary Angioedema and Gastrointestinal Complications: An Extensive Review of the Literature

A real-world study of hereditary angioedema patients due to C1 inhibitor deficiency treated with danazol in the Brazilian Public Health System

Introduction

Hereditary angioedema (HAE) due to C1 inhibitor (C1-INH) deficiency is an ultra-rare autosomal dominant inherited disease that affects 1 in 67,000 people in the world. The attacks are based on subcutaneous and submucosal edema that can lead to death if not properly managed. Considering the lack of information on the clinical management of Brazilian patients with HAE, this study aimed to identify and characterize patients with HAE-C1-INH that used danazol prophylactic treatment in the Brazilian Public Health System (SUS) and the healthcare resource utilization (HCRU).

Methods

This was an observational retrospective database study with patients treated with danazol from January 2011 until December 2021 within the SUS. The HAE cohort included patients with 12 years or older with at least one record for ICD-10 D84.1, one claim for danazol record, and at least 6 months of available history in the database.

Results

Our study included 799 patients treated in the SUS, with a mean (SD) age at danazol initiation of 40 years (16). The number of patients with HAE showed a similar distribution over this 10-year period analyzed with the highest number of patients in 2015 (n = 509) and 2016 (n = 480). A total of 253 (32%) patients had a record of at least one attack. Of those, 45 (17.8%) had at least one procedure HAE-related hospital admission, and 128 (50.6%) had at least one HAE-related hospital admission. The mean (SD) hospitalization length of stay was 5 (8) days. Over 14% (n = 36) of HAE patients with attack (n = 253) had at least one HAE-related ICU admission.

Conclusion

This database study is the strategy used to allow us to find and describe the characteristics of patients with HAE who use danazol for long-term prophylaxis in the SUS and identify HCRU outcomes of interest such as hospitalizations, inpatient, and outpatient settings. The high rate of attacks, hospitalizations, and general resource uses highlights the necessity to increase awareness of new strategies and accurate approaches to treat HAE patients. Therefore, our findings are important indicators that our health system and guidelines need to be revised and improved to properly diagnose, treat, and assist patients with HAE.

Could it be hereditary angioedema?-Perspectives from different medical specialties

Hereditary angioedema (HAE) is a rare autosomal dominant disease, with patients often suffering with associated symptoms for many years before receiving a correct diagnosis. The symptoms greatly impact a patient's quality of life (QoL) and include excruciating abdominal pain and angioedema of the skin and submucosa. Angioedema of the larynx represents a significant mortality risk in undiagnosed patients, and a large proportion of patients with HAE receive incorrect diagnoses and undergo unnecessary surgery. HAE-specific treatments can control and prevent acute life-threatening episodes, in addition to improving QoL, emphasizing the value of early diagnosis for patients. Diagnostic delay may be due to a lack of HAE awareness by healthcare professionals and the similarity of HAE symptoms with those of more common conditions, complicating differential diagnosis. The multifaceted nature of the condition may result in visits to one of many different medical settings, for example: the Emergency Room, pediatrics, general practice, otolaryngology, gastroenterology, and dermatology. Therefore, it is crucial that physicians in multiple healthcare specialties are aware of the disease to ensure that patients with HAE receive a timely diagnosis. Using patient cases from various medical specialties, this review highlights the necessity for cross-specialty awareness of HAE and outlines the essential information for the various healthcare professionals that may encounter a patient with HAE symptoms, in order to effectively treat and/or diagnose HAE.

Hereditary Angioedema

Hereditary angioedema (HAE) is a rare autosomal dominant genetic disorder that usual results from a decreased level of functional C1-INH and clinically manifests with intermittent attacks of swelling of the subcutaneous tissue or submucosal layers of the respiratory or gastrointestinal tracts. Laboratory studies and radiographic imaging have limited roles in evaluation of patients with acute attacks of HAE except when the diagnosis is uncertain and other processes must be ruled out. Treatment begins with assessment of the airway to determine the need for immediate intervention. Emergency physicians should understand the pathophysiology of HAE to help guide management decisions.

Recurrent abdominal pain as the only clinical manifestation of hereditary angioedema type II

Recurrent abdominal pain is a common reason for consultation in Gastroenterology. The differential diagnosis includes hereditary angioedema (HAE), a rare disorder characterized by recurrent episodes of angioedema, without urticaria or pruritus, which most often affects the skin, but also mucosal tissues of the gastrointestinal tract, triggered by diverse factors such as infections, trauma, surgery, drugs, or stress. It is a disease with a difficult diagnosis due to its heterogeneous and transitory clinical features, so having a clinical suspicion in the appropriate context would allow the administration of a specific treatment and avoid unnecessary examinations. We present the case of a 19-year-old male followed-up for recurrent abdominal pain that, after numerous microbiological, endoscopic, and radiological examinations, complement tests were requested, obtaining low levels of C4 with increased levels of C1 inhibitor and reduced functional activity, being diagnosed with HAE type II.

Rare, Overlooked, or Underappreciated Causes of Recurrent Abdominal Pain: A Primer for Gastroenterologists

Recurrent abdominal pain is a common reason for repeated visits to outpatient clinics and emergency departments, reflecting a substantial unmet need for timely and accurate diagnosis. A lack of awareness of some of the rarer causes of recurrent abdominal pain may impede diagnosis and delay effective management. This article identifies some of the key rare but diagnosable causes that are frequently missed by gastroenterologists and provides expert recommendations to support recognition, diagnosis, and management with the ultimate aim of improving patient outcomes.

Bowel obstruction secondary to internal hernia in a hereditary angioedema patient: a case report

BACKGROUND

Gastrointestinal attacks are frequent symptoms in patients diagnosed with hereditary angioedema (HAE). Cases of self-limited bowel intussusception and unneeded exploratory laparotomy due to lack of knowledge about HAE have been reported. Furthermore, after the introduction of C1-esterase inhibitor (C1-INH) concentrate, the recommended medication for HAE attacks, treatment has become typically medical in nature. We share a rare case where operative exploration was indicated to resolve a mechanical small bowel obstruction secondary to an HAE attack.

CASE REPORT

An 80-year-old woman with HAE presented with lower left abdominal pain, vomiting, and nausea. Computed tomography (CT) showed edema of the small bowel and stomach as well as possible signs of mechanical small bowel obstruction. The patient was treated with C1-INH concentrate but showed only mild signs of relief, warranting diagnostic laparoscopy. Intraoperative findings showed internal herniation and strangulation of the small bowel caused by adhesions forming a band. After surgical intervention, no bowel resection was needed.

CONCLUSION

Although C1-INH concentrate remains the principal treatment for HAE, gastrointestinal attacks may potentially cause surgical emergencies.

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.

Hereditary Angioedema: A Gynecology and Obstetrics Perspective

Hereditary angioedema is an autosomal dominant genetic disease that causes tissue edema mediated by bradykinin. The angioedema attacks have several triggers including stress, trauma, infection, and increased estrogens levels. This explains the greater incidence and clinical severity in women, which are usually asymptomatic until puberty, when the attacks begin to occur. It may involve multiple locations on the body, leading to complications, such as surgical intervention prompt by severe acute abdominal pain, and laryngeal edema that can culminate in death from asphyxia. This is of particular concern as this angioedema does not respond to life-saving medications commonly used in its treatment, namely, high doses of second-generation antihistamines, corticosteroids, and epinephrine. Hereditary angioedema attacks are treated with specific medication that includes icatibant, ecallantide, and C1 inhibitor, the latter being also used in short-term and long-term prophylaxis. There are other pharmacological strategies for long-term prophylaxis like lanadelumab, danazol, stanozolol, aminocaproic acid, and tranexamic acid. During pregnancy and lactation, the preferred treatment and prophylaxis is C1 inhibitor.

We report a case of hereditary angioedema describing its chronological evolution over a period of a woman's life, and highlighting some of the specificities of this pathology that intersect with the specialty of Obstetrics and Gynecology. Our aim is to draw attention to these particularities, namely the triggering factors of crisis, the need for high suspicion of the diagnosis, and the treatment and prophylaxis options for pregnant and non-pregnant women that can make the difference between life and death. To achieve a favorable outcome, the multidisciplinary teamwork between the specialties of Immunoallergology and Obstetrics and Gynecology was crucial.

Hereditary Angioedema

Hereditary angioedema (HAE) is a rare autosomal dominant genetic disorder that usual results from a decreased level of functional C1-INH and clinically manifests with intermittent attacks of swelling of the subcutaneous tissue or submucosal layers of the respiratory or gastrointestinal tracts. Laboratory studies and radiographic imaging have limited roles in evaluation of patients with acute attacks of HAE except when the diagnosis is uncertain and other processes must be ruled out. Treatment begins with assessment of the airway to determine the need for immediate intervention. Emergency physicians should understand the pathophysiology of HAE to help guide management decisions.

Gastrointestinal manifestations of angioedema: a potential area of misdiagnosis

Abdominal pain is one of the most common conditions leading people to the emergency department. An uncommon but well described cause of abdominal pain is angioedema of the gastrointestinal tract due to recurrent angioedema without wheals. Abdominal involvement is very common in hereditary angioedema (HAE), but it is also described in acquired angioedema and allergic forms. In patients with HAE, the involvement of gastrointestinal tract with resultant abdominal pain occurs in 43-93% of cases. Attacks can involve the entire gastrointestinal tract, such as the oropharynx, small intestine, colon, liver, or pancreas. Pain is the most common gastrointestinal symptom, and it may occur for many years even without cutaneous or respiratory symptoms. The case report we included in this article emphasizes the importance of accurate evaluation of personal and family history in patients with a long history of acute, severe, and unexplained abdominal pain, and it gives an example of how diagnostic delay may be longer if gastroenterological symptoms are the predominant clinical presentation. Furthermore, sometimes the simultaneous presence of concomitant gastrointestinal disorders and HAE may cause difficulties in differential diagnosis. Gastroenterologists and other physicians should add HAE to their list of potential causes of unexplained abdominal pain. The initiation of appropriate prophylaxis and treatment will prevent needless suffering and useless surgical and medical procedures.

Colonic Intussusception Secondary to Hereditary Angioedema

Hereditary angioedema (HAE) is a rare genetic disease with numerous gastrointestinal manifestations. Intussusception, although rare, has been a reported complication with documentation of bowel wall edema on endoscopy during an acute flare. With the advent of synthetic C1 esterase inhibitors, this disease has become more effectively treatable. This case report shows a HAE flare complicated by colonic intussusception, treated with C1 esterase inhibitor, with complete endoscopic resolution seen on hospital day 5. This case provides evidence that with proper medical treatment, an HAE flare with intussusception has the potential to resolve without any further need for surgical or endoscopic intervention.

Clinical presentation of hereditary angioedema

Hereditary angioedema (HAE) is a rare, autosomal dominant disease caused by a deficiency in the C1-inhibitor protein. It is characterized by recurrent episodes of nonpruritic, nonpitting, subcutaneous or submucosal edema that typically involves the extremities or the gastrointestinal tract. However, the genitourinary tract, face, oropharynx, and/or larynx may be affected as well. Symptoms often begin in childhood, worsen at puberty, and persist throughout life, with unpredictable severity. Patients who are untreated may have frequent attacks, with intervals that can range from every few days to rare episodes. Minor trauma and stress are frequent precipitants of swelling episodes, but many attacks occur without clear triggers. HAE attacks may be preceded by a prodrome and/or be accompanied by erythema marginatum. The swelling typically worsens over the first 24 hours, before gradually subsiding over the subsequent 48 to 72 hours. Although oropharyngeal swelling is less frequent, more than half of patients have had at least one episode of laryngeal angioedema during their lifetime. Attacks may start in one location and spread to another before resolving. HAE attacks that involve the abdomen or oropharynx have been associated with significant morbidity and mortality. Abdominal attacks can cause severe abdominal pain, nausea, and vomiting. Bowel sounds are often diminished or silent, and guarding and rebound tenderness may be present on physical examination. These findings may lead to unnecessary abdominal imaging and procedures. Fluid shifts into the interstitial space or peritoneal cavity can cause clinically significant hypotension. Laryngeal edema poses the greatest risk for patients with HAE. Although prompt diagnosis and treatment improves outcomes, the variable presentation of HAE can make it difficult to diagnose.

Hereditary angio-oedema as a rare cause of small-bowel obstruction

A 52-year-old man with known hereditary angio-oedema (HAE) presented with a 2-day history of progressive severe abdominal pain, distension, nausea, vomiting and constipation. CT of his abdomen and pelvis showed small-bowel obstruction and ascites. HAE is a rare autosomal dominant disorder caused by a C1 esterase deficiency and involves episodic oedema of subcutaneous and mucosal tissues. It commonly affects the face and limbs, causing deformity; the respiratory tract, causing life-threatening laryngeal swelling; and the gastrointestinal tract, causing small-bowel obstruction. An infusion of a C1 esterase inhibitor was given to the patient. His symptoms resolved within 6 hours, and a repeat CT showed complete resolution 24 hours later. Small-bowel obstruction in HAE is often misdiagnosed, leading to ineffective treatment and unnecessary surgery. Therefore, this should be suspected in patients with HAE presenting with an acute abdomen, and clinicians should understand the unique treatment required.

Clinical Conditions that Masquerade as Urticaria

Chronic urticaria is one of the most commonly diagnosed dermatoses. Following diagnosis, correct identification and proper treatment significantly reduces disease activity, thereby improving the patient’s quality of life. However, there is an extensive differential diagnosis for chronic urticaria that, if missed, can lead to life-threatening sequelae. Many of the diseases that masquerade as urticaria are rare and often have a significant delay in diagnosis. This paper aims to fill the gap in the literature by clearly characterising the cutaneous eruptions and atypical findings in many of the most common mimickers of chronic urticaria. Conditions such as erythema marginatum seen in conjunction with hereditary angioedema, urticaria vasculitis, autoinflammatory cryopyrin-associated periodic syndromes, adult-onset Still’s disease and systemic onset juvenile arthritis, Schnitzler syndrome, erythema multiforme, and cutaneous mastocytosis will be discussed.

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

A 27-year-old Emirate man presented to Cleveland Clinic Abu Dhabi emergency department with a 4 year history of recurrent episodes of severe swellings affecting different parts of his body. He used to get 2 swelling episodes every week affecting either his face, hands, feet or scrotum and severe abdominal pain twice a week. Abdominal CT scan and a colonoscopy showed bowel wall oedema. There was no family history of similar complaint or of hereditary angioedema (HAE). Complement studies confirmed the diagnosis of HAE type II. He was commenced on danazol 100 mg twice daily and his symptoms resolved. This case report highlights the importance of considering HAE in patients with recurrent unexplained abdominal pain even in the absence of positive family history of HAE.

Non-Surgical Management of Colo-Colonic Intussusception in Patients with Hereditary Angioedema

Patient: Female, 17

Final Diagnosis: Colo-colonic intussusception

Symptoms: Abdominal pain

Medication: —

Clinical Procedure: —

Specialty: Radiology

Extensive Cervico-Thoraco-Abdominal Attacks of Angioedema: CT Diagnosis in Two Unusual Cases

Angioedema (AE) classically manifests as an acute transient swelling of extra-visceral spaces, subcutaneous and submucosal tissues. Sometimes it may be a life-threatening condition. The causes are numerous, and the common denominator is an increased vascular permeability allowing diffusion or extravasation of fluid from the vascular bed to the interstitial space. The severity of AE is related to the cause, body location, and extension. We hereby report two very unusual cases characterized by a massive attack of AE from the left cervical area to the pelvis through the length of the mediastinum and axial posterior retroperitoneum. The diagnosis was established by CT. The first case was found related to drug intake, and the second appeared idiopathic.

Diagnosis and screening of patients with hereditary angioedema in primary care

Hereditary angioedema (HAE) is a rare autosomal dominant disease that commonly manifests with episodes of cutaneous or submucosal angioedema and intense abdominal pain. The condition usually presents due to a deficiency of C1 esterase inhibitor (C1-INH) that leads to the overproduction of bradykinin, causing an abrupt increase in vascular permeability. A less-understood and less-common form of the disease presents with normal C1-INH levels. Symptoms of angioedema may be confused initially with mast cell-mediated angioedema, such as allergic reactions, and may perplex physicians when epinephrine, antihistamine, or glucocorticoid therapies do not provide relief. Similarly, abdominal attacks may lead to unnecessary surgeries or opiate dependence. All affected individuals are at risk for a life-threatening episode of laryngeal angioedema, which continues to be a source of fatalities due to asphyxiation. Unfortunately, the diagnosis is delayed on average by almost a decade due to a misunderstanding of symptoms and general lack of awareness of the disease. Once physicians suspect HAE, however, diagnostic methods are reliable and available at most laboratories, and include testing for C4, C1-INH protein, and C1-INH functional levels. In patients with HAE, management consists of acute treatment of an attack as well as possible short- or long-term prophylaxis. Plasma-derived C1-INH, ecallantide, icatibant, and recombinant human C1-INH are new treatments that have been shown to be safe and effective in the treatment of HAE attacks. The current understanding of HAE has greatly improved in recent decades, leading to growing awareness, new treatments, improved management strategies, and better outcomes for patients.