A different kind of edema - hereditary angioedema

This is the 3411th article of Da Yi Xiao Hu

This edema is a disease

Weiwei (pseudonym), an 11-year-old boy, had recurrent swelling of his hands, feet, and face for the past 5 years, with 6-7 episodes per year, accompanied by a hoarse voice and difficulty breathing. Each episode lasted 2-3 days and disappeared with home remedies. There was occasional abdominal pain, which varied in type at the beginning of the episode, but there was no itching, redness, or eczema. These episodes were apparently not related to any food, medication, or other occasional illness. Family history showed that the mother had a history of similar episodes since childhood, and Weiwei's brother also had a similar history of episodes and died of respiratory distress during a similar episode at the age of 8.

During physical examination, Weiwei was found to have mild nonpitting edema of the eyelids, lips, and dorsum of the hands, with mild increased voice. Indirect laryngoscopy showed laryngeal edema involving the aryepiglottic folds and true and false vocal cords. The clinical diagnosis was hereditary angioedema.

Blood count, urinalysis, liver and kidney function tests were normal. Plasma complement C4 was estimated by common pathway screening and was reduced to 0.14 g/L (normal 0.20-0.50 g/L). C1 esterase inhibitor was also estimated to be reduced by 29% (normal 70-130%). The patient was treated with 1 mg stanozolol orally twice daily for six weeks and the current episode was resolved. When the remission was sustained, the dose was reduced to 1 mg once daily for 6 months. The liver function was tested regularly during treatment and was normal. The parents were questioned about the nature of the disease and although the mother had very few mild episodes that did not require any active intervention, her serum C4 level was reduced to 0.06 g/L and C1 esterase inhibitor to 29%, while the father had normal levels of both parameters.

What is hereditary angioedema

Hereditary angioedema is a primary complement deficiency disease characterized by paroxysmal, self-limited, localized systemic subcutaneous non-pitting edema. The disease can occur at any age, but most cases occur in childhood or adolescence, often accompanied by abdominal pain, nausea and vomiting, and decreased serum C1 esterase inhibitor (C1INH), and generally has a family history. The incidence of the disease is about 1/50,000-100,000.

What are the symptoms of hereditary angioedema?

Swelling of the skin and mucous membranes is usually paroxysmal, recurrent, and non-pitting. It is generally not itchy and is not accompanied by urticaria. The swelling will gradually increase within 12-18 hours and gradually subside after 48-72 hours. Edema often occurs on the face, tongue, throat, hands and feet, external genitalia, or one side of the limbs where the tissue is loose. Single attacks are more common, and occasionally occur in more than two places. It may be accompanied by hoarseness, difficulty swallowing, and acute abdominal changes in the lower gastrointestinal tract. In severe cases, breathing difficulties or even suffocation may occur. Patients are born with C1INH deficiency, but the childhood is mostly mild, and the disease often does not occur until adolescence, and the number of attacks decreases in old age.

How is hereditary angioedema treated?

1. Systemic treatment

Generally, symptomatic treatment is adopted. In case of acute attack, C1INH concentrate or recombinant C1INH, bradykinin receptor antagonists and kallikrein inhibitors can be selected. Antifibrinolytic drugs such as aminocaproic acid and androgens (such as stanozolol) can also be selected for treatment. Opioid preparations are taken for abdominal colic. When laryngeal edema occurs, drugs such as epinephrine, hydrocortisone, ephedrine, aminophylline, etc. can be selected for treatment.

2. Local treatment

Localized edema can be treated with 10% calamine lotion or 1% menthol lotion. If acute laryngeal edema occurs, endotracheal intubation should be performed promptly, and tracheotomy should be performed if necessary.

How to prevent hereditary angioedema

1. Avoid consanguineous marriage. Those with a family history can receive genetic counseling before having children.

2. Avoid inducing factors, such as trauma, infection, etc.

This project is funded by Shanghai Science Education Development Foundation (Project No.: B202117)

Author: Baoshan Branch of Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine

Dr. Xia Lemin, MD, Department of Hematology