My cousin has swelling episodes. What treatments help him?

Question

Hello doctor,

My uncle has hereditary angioedema, and now my 18-year-old cousin has started developing swelling episodes without hives, usually around his face and hands. He had C4 and C1 esterase inhibitor tests done. C4 was 8 mg/dL, and the C1-INH level was 6 mg/dL.

We are quite anxious and would appreciate some clarity on the following:

Does this confirm type I HAE?
What are the next steps for treatment and prevention?
Can acute episodes be life-threatening, especially if they involve throat swelling?
Also, is long-term prophylaxis needed, or do people just treat attacks as they occur?
Would you recommend genetic counseling for other family members?

Kindly suggest.

Answer 1

Hello,

Welcome to icliniq.com.

I understand your concern.

Your cousin’s symptoms of recurrent swelling without hives, combined with low C4 (complement component 4) and significantly reduced C1 (complement component 1) esterase inhibitor infusions (C1-INH) levels, are consistent with a diagnosis of type I hereditary angioedema (HAE), which is the most common form.

Type I HAE is caused by decreased production of functional C1-INH, leading to unregulated bradykinin activity and episodes of swelling. These episodes can be life-threatening, particularly if they involve the upper airway, such as the tongue or larynx, so prompt recognition and treatment are crucial. The mainstay of acute treatment includes medications like Icatibant, a bradykinin receptor antagonist, or C1-INH replacement therapy, which can be administered at home in some cases.

For long-term prevention, prophylactic treatment is considered if the attacks are frequent, severe, or significantly affect quality of life, and options include regular C1-INH infusions or newer agents like Lanadelumab. Every patient’s management is individualized based on the frequency and severity of attacks.

Genetic counseling is recommended for other family members, especially first-degree relatives, since HAE is inherited in an autosomal dominant pattern, meaning there is a 50 percent chance of transmission from an affected parent. Early diagnosis is essential to ensure that affected individuals have access to appropriate treatment and emergency planning.

I hope this helps.