A woman in her 30s who experienced recurrent, nonspecific gastrointestinal symptoms was diagnosed with angioedema of the small intestine — also known as intestinal angioedema, or sometimes angioedema of the bowel — related to the use of an angiotensin-converting enzyme (ACE) inhibitor to treat high blood pressure, according to a case report.
The woman’s symptoms eased after stopping treatment with the medication, lisinopril, with no recurrence of angioedema attacks, or sudden swelling in the skin, after three months, the researchers noted.
“The information provided is intended to assist health care professionals in recognizing clues associated with angioedema of the small intestine, allowing timely diagnosis and effective treatment for patients with [intestinal] angioedema,” the researchers wrote.
The case report, “Recognizing Clues Associated With Angioedema of the Small Intestine: A Case Report,” was published in the Journal of Emergency Nursing by two nursing professors at The University of Tampa.
Angioedema is a condition marked by swelling in the deeper layers of the skin or mucus membranes. Drug-induced nonallergic angioedema is an adverse effect of certain medications — most commonly, angiotensin-converting enzyme (ACE) inhibitors. These drugs are often used to treat people with high blood pressure, or hypertension, and other cardiovascular conditions.
ACE inhibitors usually cause angioedema in the face, lips, tongue, or throat, leading to swelling and sometimes blocked airways. But it’s less well known that they can also cause swelling in the small intestine.
Diagnostic journey detailed for woman with intestinal angioedema
Here, a research team in Florida described the diagnostic journey of a 39-year-old woman who sought emergency department treatment for mild to severe abdominal pain that had started two days earlier. She had a history of several months of intermittent nonspecific gastrointestinal symptoms, such as abdominal pain, loss of appetite, bloating, nausea, vomiting, frequent burping, and diarrhea.
She also had hypertension, for which she was treated, for five years, with hydrochlorothiazide, a diuretic, and lisinopril, an ACE inhibitor. The woman also reported having experienced one episode of mild lip and facial swelling two months earlier, which was effectively treated with antihistamines and corticosteroids.
Following that episode, she was referred to an allergist, who found that her C1 esterase inhibitor (C1-INH) activity was normal. This ruled out hereditary angioedema, which is typically caused by low levels or impaired function of C1-INH. In such cases, excess bradykinin accumulates, leading to blood vessel dilation, fluid leakage, and swelling
Besides abdominal symptoms, a physical examination indicated the abdomen was slightly distended, with generalized tympany — a percussion sound when tapping due to the accumulation of air and gas throughout the abdomen, which may indicate a bowel condition — and discomfort/pain when light pressure was applied.
A CT scan also revealed swelling in a region of the small bowel with inflammation signs. This was suggestive of a bowel condition, such as an inflammatory disease or infection, or a mechanical obstruction. Ischemia, or a lack of blood flow to a part of the bowel, can also cause these symptoms.
Laboratory analysis indicated a moderate increase in the levels of leucocytes, or white blood cells, which could indicate an inflammatory or infectious process.
Clinicians started the woman on treatment with intravenous, or into-the-vein, morphine, which effectively controlled her abdominal pain, and intravenous haloperidol for nausea and vomiting. Her condition improved, and she was discharged with no adjustments to her medication or additional recommendations.
Woman’s abdominal symptoms resolved after stopping ACE inhibitor
Two weeks later, however, she returned to the emergency department with the same symptoms, as well as bowel inflammation signs in the CT scan. She was referred to a specialist in gastrointestinal conditions, who suspected ACE inhibitor-induced angioedema and immediately discontinued lisinopril.
The woman’s abdominal symptoms completely resolved after three days, according to the report.
“Even though the exact pathogenetic [disease-causing] mechanism of ACE inhibitor-induced angioedema is not fully understood, current research posits that the inhibitory actions of these medications prevent the breakdown of bradykinin,” the researchers wrote.
[This] case report underscores the challenges health care providers face in diagnosing [intestinal] angioedema and the crucial role of emergency nurses in recognizing key warning signs such as nonspecific abdominal complaints in patients on angiotensin-converting enzyme [ACE] inhibitor therapy.
The team reported that several medications the woman subsequently used to control blood pressure triggered similar symptoms. After further adjustments, the patient’s blood pressure was well controlled with triamterene/hydrochlorothiazide, nebivolol, and amlodipine. The woman remained free from previous abdominal symptoms for at least three months, per the report.
According to the researchers, “[this] case underscores the challenges health care providers face in diagnosing [intestinal] angioedema and the crucial role of emergency nurses in recognizing key warning signs such as nonspecific abdominal complaints in patients on angiotensin-converting enzyme [ACE] inhibitor therapy.”
“Early identification of this condition can prevent unnecessary procedures, prevent prolonged symptoms, and improve patient outcomes,” the team added.