Case of woman in China shows impact of delayed diagnosis in HAE
Simple blood test gives patient answers 9 years after start of symptoms
Written by |
It wasn’t until nearly a decade after she first started experiencing symptoms that a woman in China was diagnosed with hereditary angioedema (HAE), despite a family history of swelling bouts and years of abdominal pain, as described in a new report.
A routine blood test at age 39, after nine years of misdiagnoses, showed low levels of a protein that’s key for preventing excessive swelling, according to the researchers. The woman was ultimately diagnosed with HAE.
“The [nine]-year diagnostic delay experienced by the patient highlights the prevalent challenges in the diagnosis and management of HAE in China,” the researchers wrote.
The team noted that, “according to the literature, the average diagnostic delay of HAE patients in China is as long as 12.6 years, primarily attributed to insufficient clinical awareness and extremely limited accessibility to confirmatory tests.”
The study, “Hereditary angioedema type 1 in a 39-year-old woman with a three-generation pedigree: a case report,” was published in the journal Allergy Medicine.
Angioedema refers to swelling of the skin and mucus membranes. This can occur due to allergic reactions, but in HAE, swelling is triggered by an underlying genetic mutation that is passed from parents to their biological children. Type 1 HAE, the most common form of this rare disease, is caused by mutations that lead to low levels of the protein C1 esterase inhibitor (C1-INH).
Delayed HAE diagnosis in China common due to lack of testing
Diagnosing HAE type 1 is fairly straightforward, as a simple blood test can measure whether or not a patient has abnormally low C1-INH levels. However, given that HAE is rare, doctors often don’t think to run this test. Further, not all clinics have the specific equipment needed to conduct such testing.
That was the case for the woman in this report. During a pregnancy when she was 30, she started to experience bouts of swelling in her limbs accompanied by abdominal pain — a common HAE symptom triggered by swelling in the membranes around the intestines. Many of her family members also had experienced occasional bouts of swelling, the report noted.
But because the woman had a history of allergic rhinitis — that is, allergies causing nasal symptoms — her doctors initially thought that her swelling was a symptom of allergies. Her abdominal pain was misdiagnosed as acute gastroenteritis, or inflammation of the digestive tract, which usually occurs due to an infection.
According to the researchers, “the patient’s recurrent abdominal pain and [swelling] were misdiagnosed as gastroenteritis or allergic disorders for an extended period due to the lack of distinctive clinical recognition.”
The nine-year diagnostic journey of this case … serves as a critical alert for non-specialist physicians. To prevent similar delays and enhance the overall diagnostic and therapeutic standards for HAE, we must heighten vigilance.
In the years that followed, the woman received a range of medications aimed at treating her suspected allergy, but none of them were effective. Finally, when she was 39, she was evaluated by clinicians at a specialty center, who ran a blood test that showed her C1-INH levels were well below the normal range, leading to a diagnosis of HAE type 1.
“The nine-year diagnostic journey of this case … serves as a critical alert for non-specialist physicians. To prevent similar delays and enhance the overall diagnostic and therapeutic standards for HAE, we must heighten vigilance,” the researchers concluded, adding that “emphasis should be placed on recognizing [HAE’s] core features.”
In this case, “the ineffectiveness of conventional antihistamines and glucocorticoids serves as a critical diagnostic hint” that was overlooked, the team noted. Further, “[10] members of the family had similar attack histories,” the researchers noted.
One key issue highlighted by the scientists was the lack of necessary testing procedures in China.
“Only approximately [five] hospitals nationwide currently offer C1-INH concentration testing, and [laboratory procedures] have not yet been approved for clinical use in China, which constitutes the major bottleneck to timely HAE confirmation,” the researchers wrote. Such testing “should be conducted to make a clear diagnosis,” the team wrote.
