Angioedema with severe acute abdominal pain: Think of hereditary angioedema

Angioedema can be either mast cell-(histamine-)mediated or bradykinin-mediated. Treatment approaches for the two types are very different, making differential diagnosis critical. Severe acute abdominal pain caused by intestinal angioedema is commonly misdiagnosed, especially when associated with bradykinin-mediated angioedema. After describing a typical clinical scenario and diagnostic journey of a patient with recurrent, undiagnosed abdominal pain due to hereditary angioedema (HAE), a rare variant of bradykinin-mediated angioedema, we delve into the classification and differential diagnosis of the various types of angioedema and provide an overview of appropriate management with an emphasis on the bradykinin-mediated types. Bradykinin-induced angioedema may be inherited or acquired and is infrequent compared to mast cell-mediated angioedema. HAE is a rare disease characterized by recurrent attacks of non-urticarial, nonpruritic edema usually affecting the face, respiratory tract, extremities, gastrointestinal tract, and genitalia. Unlike mast cell-mediated angioedema, painful abdominal symptoms are prevalent in bradykinin-mediated angioedema and are sometimes the only manifestation of an attack, increasing the likelihood of initial misdiagnosis as appendicitis or other forms of acute abdomen. It is important for gastroenterologists to be vigilant for the possibility of angioedema pathology in patients presenting with undiagnosed, recurrent, abdominal symptoms to facilitate accurate diagnosis and effective treatment.

Consensus on treatment goals in hereditary angioedema: A global Delphi initiative

BACKGROUND

Hereditary angioedema (HAE) is a rare, life-threatening genetic disorder characterized by recurrent episodes of subcutaneous or submucosal angioedema. The ultimate goals of treatment for HAE remain ill-defined.

OBJECTIVES

The aim of this Delphi process was to define the goals of HAE treatment and to examine which factors should be considered when assessing disease control and normalization of the patient's life.

METHODS

The Delphi panel comprised 23 participants who were selected based on involvement with scientific research on HAE or coauthorship of the most recent update and revision of the World Allergy Organization/European Academy of Allergy and Clinical Immunology guideline on HAE. The process comprised 3 rounds of voting. The final round aimed to aggregate the opinions of the expert panel and to achieve consensus.

RESULTS

Two direct consensus questions were posed in round 2, based on the responses received in round 1, and the panel agreed that the goals of treatment are to achieve total control of the disease and to normalize the patient's life. For the third round of voting, 21 statements were considered, with the participants reaching consensus on 18. It is clear from the wide-ranging consensus statements that the burdens of disease and treatment should be considered when assessing disease control and normalization of patients' lives.

CONCLUSIONS

The ultimate goal for HAE treatment is to achieve no angioedema attacks. The availability of improved treatments and disease management over the last decade now makes complete control of HAE a realistic possibility for most patients.

Diagnosis, Course, and Management of Angioedema in Patients With Acquired C1-Inhibitor Deficiency

BACKGROUND

Acquired angioedema due to C1-inhibitor deficiency (C1-INH-AAE) is a rare disease with no prevalence data or approved therapies.

OBJECTIVE

To report data on patients with C1-INH-AAE followed at Angioedema Center, Milan (from 1976 to 2015).

METHODS

Diagnostic criteria included history of recurrent angioedema without wheals; decreased C1-INH antigen levels and/or functional activity of C1-INH and C4 antigen less than 50% of normal; late symptom onset (>40 years); no family history of angioedema and C1-INH deficiency.

RESULTS

In total, 77 patients (58% females; median age, 70 years) were diagnosed with C1-INH-AAE and 675 patients with hereditary angioedema due to C1-INH deficiency (C1-INH-HAE) (1 patient with C1-INH-AAE/8.8 patients with C1-INH-HAE). Median age at diagnosis was 64 years. Median time between symptom onset and diagnosis was 2 years. Sixteen patients (21%) died since diagnosis, including 1 because of laryngeal edema. Angioedema of the face was most common (N = 63 [82%]), followed by abdomen (N = 51 [66%]), peripheries (N = 50 [65%]), and oral mucosa and/or glottis (N = 42 [55%]). Forty-eight of 71 patients (68%) had autoantibodies to C1-INH. In total, 56 patients (70%) used on-demand treatment for angioedema including intravenous pdC1-INH 2000 U (Berinert, CSL Behring, Marburg, Germany) (N = 49) and/or subcutaneous icatibant 30 mg (Firazyr, Shire; Milano, Italy) (N = 27). Eventually, 8 of 49 patients receiving pdC1-INH became nonresponsive; all had autoantibodies. Thirty-four patients received long-term prophylaxis with tranexamic acid (effective in 29) and 20 with androgens (effective in 8).

CONCLUSIONS

The incidence of C1-INH-AAE was 1 for every 8.8 patients with C1-INH-HAE. Thirty percent of the deaths were related to the disease. Treatments approved for C1-INH-HAE are effective in C1-INH-AAE, although with minimal differences.

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.

Rituximab therapy in a patient with low grade B-cell lymphoproliferative disease and concomitant acquired angioedema

Acquired angioedema is often associated with significant morbidity. An underlying lymphatic malignancy, autoimmune disorder, adenocarcinoma, or other malignancy may be present. Screening for these disorders should occur in all patients with acquired angioedema as treatment may result in resolution of angioedema.