Misdiagnosis of HAE Is Common During Pregnancy, but Successful Delivery Is Possible

A new case report illustrates the challenges of diagnosing hereditary angioedema (HAE), particularly during pregnancy, but also shows that pregnancy and delivery can be successfully managed in these cases.

The report, published in the Canadian Medical Association Journal, suggests that patient management should include collaboration with specialists in HAE as well as treatment with plasma-derived C1 inhibitor (C1-INH).

“Hereditary angioedema attacks can be triggered by minor trauma, stress or hormonal changes (eg, pregnancy, menstruation or use of oral contraceptives), leading to increased levels of bradykinin, which increase vascular permeability and cause angioedema,” the authors wrote.

“During pregnancy, delivery and breastfeeding, guidelines recommend plasma-derived C1-INH (a blood product that replaces the deficient C1-INH) for both on-demand and prophylactic treatment, given its long history of efficacy and safety.”

Read more about HAE diagnosis

The patient was a 23-year-old woman with a history of anxiety and substance use (prior to pregnancy) but no family history of swelling. During her pregnancy, she presented with 5 episodes of abdominal pain, nausea, vomiting, swelling of the hands and feet, and nonpruritic rash. Not recognizing HAE, her clinicians assured her that the symptoms would abate postpartum.

However, after a successful delivery, the patient’s symptoms recurred, increasing in severity, and she was misdiagnosed as having a Cesarean wound infection. Treatment with antibiotics led to a temporary improvement, but the episodic swelling, abdominal pain, and nausea recurred. Despite visiting 5 different specialists, angioedema was not considered.

Ten months after delivery, the patient visited an outpatient infectious disease clinic where they ordered measurements of her C4 and C1-INH levels. Finally, based on markedly reduced levels of both C4 and C1-INH, genetic testing was performed and a diagnosis of HAE was made.

Since then, the patient has responded well to treatment with C1-INH prophylaxis with icatibant as needed for episodic swelling. The authors recommend that clinicians employ the widely available and inexpensive laboratory tests for HAE in any patient suspected of having the condition and genetic testing in symptomatic patients with normal test results.

Reference

Chair I, Lacuesta G, Nash CM, Cook V. A challenging diagnosis: hereditary angioedema presenting during pregnancy. CMAJ. 2022;194(37):E1283-E1287. doi:10.1503/cmaj.220604