Study Links Age of Onset and Year of Birth to Delayed Diagnosis for Hereditary Angioedema

According to a study recently published in Allergy and Asthma Proceedings, certain risk factors may increase an individual’s likelihood of receiving a late diagnosis for hereditary angioedema. Hereditary angioedema is under-diagnosed in many parts of the world, in no small part due to the difficulty some physicians can have identifying the condition.

The study, conducted in the People’s Republic of China (PRC), was based on self-assessments from 107 hereditary angioedema patients who had previously received treatment at the influential Peking Union Medical College Hospital at some point in the last 35 years.

About Hereditary Angioedema

Agioedema is a skin reaction similar to hives, but occurring in deeper layers of tissue. Angioedema is what makes some people “puff up” during an allergic reaction. Angioedema often accompany hives as part of an allergic reaction, but sometimes that isn’t the case.

Hereditary angioedema (HAE), as the name would imply, is instead caused by mutations to the human genetic code.

There are three types of hereditary angioedema which are differentiated by their underlying causes and genetic origins. Types I and II, the focus of the Allergy and Asthma Proceedings study, are caused by mutations to a gene called SERPING1.

In otherwise healthy people, SERPING1 is responsible for coding the production of an important regulatory protein called C1 inhibitor. Normally, C1 inhibits excessive inflammation by blocking the activity of certain blood proteins. When functioning C1 is not present in adequate amounts, however, inflammation can run unchecked. Type I HAE is caused by complete underproduction of C1 inhibitor, while type II is caused by regular production of a non-functional form.

The condition can be difficult to initially diagnose, because to an untrained eye hereditary angioedema can appear like any other anaphylactic episode. In cases where inflammation affects the airway, HAE can be fatal.

Age and Year of Birth Significant Predictors of Delayed Diagnosis

The Chinese study found that of the 107 respondents, the median delayed diagnosis was over 11 years. To evaluate individual responses, participants’ data was divided into groups of delayed diagnosis greater than and less than 6 years.

Two studied factors were found to have significant impacts on the length of a patient’s delayed diagnosis — their age at onset, and the decade of their birth.

Early-onset disease can often be particularly aggressive or difficult to diagnose. In a more simplified way of looking at things, early development of angioedema is simply more time on the clock to receive a late or misdiagnosis.

The decade of birth is perhaps the more “interesting” of the two findings. The study found that the earlier the year of your birth, the more likely you were to receive a late or misdiagnosis for hereditary angioedema. This figure hints at the massive strides in procedure and technology that have taken place in medicine in the last few decades alone.

Because patients who received more than one misdiagnosis were found to have longer delayed diagnoses than patients with one or none, the importance of early and accurate identification of hereditary angioedema cannot be understated.

What do you think of this study’s intriguing findings? Does the data surprise you? Share your thoughts with Patient Worthy!

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