What Is Hereditary Angioedema?

Basic Information

Causes of hereditary angioedema

The disease is autosomal dominant, and mutations in the SERPING1 gene cause functional defects that cause the disease. About half of the patients have edema associated with minor trauma, such as bumps, crushes, and so on. In addition, mood swings, infections, sudden changes in temperature, and contraception are often the causes of the disease.

Clinical manifestations of hereditary angioedema

Swelling of the mucous membrane of the skin has the characteristics of episodic, repetitive and non-depressive, and generally does not itch and is not accompanied by hives. The swelling gradually increased within 12 to 18 hours, and gradually subsided after 48 to 72 hours. Edema often occurs on the face, tongue, throat, hands, feet, external genitalia, or limb on loose tissues. Single shots are common and occasionally seen in more than two places. May be accompanied by hoarseness, difficulty swallowing, acute gastrointestinal changes in the lower digestive tract, and severe cases may have difficulty breathing or even suffocation. Patients with C1INH deficiency are present at birth, but most of them are mild in childhood. They usually develop in adolescence and reduce the number of seizures in old age.

Hereditary angioedema

Laboratory inspection

The concentration of C1 esterase inhibitor in the serum of 80% -85% of patients is reduced or their function is abnormal. C4 and C2 decreased during the onset, and C4 decreased during the quiescent period.

2. Histopathological examination

Mainly manifested as deep dermis and subcutaneous tissue, submucosal vasodilation, interstitial edema. No inflammatory cell infiltration or with a small amount of inflammatory cell infiltration.

Diagnosis of hereditary angioedema

1. Occurs in the limbs, face and throat and gastrointestinal tract.

2. The damage is sudden localized, non-depressive and non-inflammatory edema, no itching, and no wind mass damage.

3. Often accompanied by gastrointestinal edema causing abdominal cramps and nausea, vomiting, or throat suffocation caused by suffocation and life-threatening.

4. Laboratory tests showed that the levels of C4 and C2 in serum decreased, and C1 esterase inhibitors were lacking or reduced.

Differential diagnosis of hereditary angioedema

Acquired angioedema

Occurred in the loose parts of the eyelids, lips and external genitalia, often accompanied by wind masses, serum C1 esterase inhibitors, C4 and C2 levels are normal.

2. Facial erysipelas

Acute onset, systemic symptoms of chills, fever, and headache. The erythema of the affected area is edema, the surface is bright and hot, and the lymph nodes are often enlarged under the jaw or behind the ear.

3. Contact Dermatitis

There is a clear history of exposure, the lesions are limited to the contact site, and there are papules, blisters, and scabs.

Hereditary angioedema treatment

Systemic treatment

Symptomatic treatment is generally adopted. For acute attacks, C1INH concentrate or recombinant C1INH, bradykinin receptor antagonist, and kallikrein inhibitor can be selected. Antifibrinolytic drugs such as aminocaproic acid and androgens can also be selected for treatment. Take opioids for abdominal cramps. When laryngeal edema occurs, drugs such as epinephrine, hydrocortisone, aminophylline, and ephedrine can be selected.

Local treatment

Local edema can be treated with 10% calamine lotion or 1% menthol lotion. Patients with acute laryngeal edema should be intubated in time, and tracheostomy should be performed if necessary.