ANGIOEDEMA

By Gary M. White, MD

Angioedema


Angioedema is the rapid swelling (edema) of the deeper layers of skin usually caused by an IgE-mediated allergic reaction. It commonly occurs in association with urticaria. If the upper respiratory tract is involved, shortness of breath and even death may occur. Involvement of the GI tract may cause significant abdominal symptoms. Most cases are acquired but inherited forms occur. Rarely, the sun may induce angioedema (see solar angioedema).

Clinical

There is rapid swelling of the skin and underlying tissue. The periorbital area and lips are commonly affected.

Chicken-Wire Erythema

Chicken-wire erythema (CWE) is a highly characteristic pattern, seen in up to 60% of patients with angioedema associated with C1 inhibitor deficiency. CWE may precede or accompany the angioedema attack or it can be an isolated finding.

Causes Of Acquired Angioedema

Angiogram may be caused by allergy to a variety of allergens including foods and drugs, ACE inhibitors, lymphoproliferation, and/or antibody directed against the C1 inhibitor.

The C1 inhibitor forms a complex with C1 inactivating it. A deficiency in normally functioning C1 inhibitor leads to an uncontrolled activation of the classical complement pathway and an attack of angioedema can result.

C1 INHIBITOR DEFECTS

Acquired

An antibody directed against the C1 inhibitor is present (may have lymphoproliferative disease).

Inherited, Type I

There is deficient production of a functionally normal C1 inhibitory.

Inherited, Type II

There is normal production of a functionally altered C1 inhibitor.

Angioedema occurs in 0.1-1% of patients on ACE inhibitors (ACEIs), e.g., losartan [Arch Int Med 1998;158;2063]. ACEIs are thought to be able to cause angioedema by prolonging the effect of bradykinin. Most patients develop the condition within 3 weeks of starting the drug.

Workup for Acquired Cases

A complete drug history to rule out ACE inhibitor use (e.g., captopril, enalapril, or lisinopril) is important. An SPEP and lymph node exam should help exclude lymphoproliferative disease which may be associated with antibodies against C1 inhibitor.

Treatment

For life-threatening laryngeal swelling, airway protection and injection of adrenaline are indicated along with antihistamines and possibly steroids. Otherwise, stopping any offending agent and initiation of oral antihistamines should be done. See urticaria. Omalizumab is effective at reducing urticaria-associated angioedema resistant to high dose antihistamines [JEADV 2017;31l1056].

For angioedema associated with an ACE inhibitors, stopping the offending drug is indicated. Switching to another ACE inhibitor is not recommended.

Additional Pictures

Angioedema on the back of the neck.
Angioedema of the neck

This is the rare Solar Angioedema.
Solar angioedema

References

Chicken-wire erythema is a highly characteristic pattern, seen in up to 60% of patients with angioedema associated with C1 inhibitor deficiency. Acta Derm Venereol 2010;91;185-6

Saxophone Penis. Acute swelling of the penis may cause it to appear like a saxophone. This is most commonly a result of allergic contact dermatitis from rhus, but may also occur in the setting of hereditary angioedema as shown here. Indian Dermatol Online J 2015;6:462-3

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