Allergic In allergic<unk> , avoidance of the allergen and use of antihistamines may prevent future attacks. Cetirizine is a commonly prescribed antihistamine for<unk> . Some patients have reported success with the combination of a nightly low dose of cetirizine to moderate the frequency and severity of attacks, followed by a much higher dose when an attack does appear. Severe<unk>  cases may require desensitization to the putative allergen, as mortality can occur. Chronic cases require steroid therapy, which generally leads to a good response. In cases where allergic attack is progressing towards airway obstruction, epinephrine may be life-saving. Drug induction ACE inhibitors can induce<unk> . ACE inhibitors block the enzyme ACE so it can no longer degrade bradykinin; thus, bradykinin accumulates and can cause<unk> . This complication appears more common in African-Americans. In people with ACE inhibitor<unk> , the drug needs to be discontinued and an alternative treatment needs to be found, such as an angiotensin II receptor blocker (ARB), which has a similar mechanism but does not affect bradykinin. However, this is controversial, as small studies have shown some patients with ACE inhibitor<unk>  can develop it with ARBs, as well. Hereditary In hereditary<unk>  (HAE), specific stimuli that have previously led to attacks may need to be avoided in the future. It does not respond to antihistamines, corticosteroids, or epinephrine. Acute treatment consists of C1-INH (C1-esterase inhibitor) concentrate from donor blood, which must be administered intravenously. In an emergency, fresh frozen blood plasma, which also contains C1-INH, can also be used. However, in most European countries, C1-INH concentrate is only available to patients who are participating in special programmes. The medications ecallantide and icatibant may be used to treat attacks. In 2017 these medications cost between 5,700 and 14,000 per dose in the United States, prices that tripled in two years. In those given icatibant, specialists monitor is recommended. Acquired In acquired<unk> , HAE types I and II, and nonhistaminergic<unk> , antifibrinolytics such as tranexamic acid or ε-aminocaproic acid may be effective. Cinnarizine may also be useful because it blocks the activation of C4 and can be used in patients with liver disease, whereas androgens cannot. Prophylaxis Future attacks of HAE can be prevented by the use of androgens such as danazol, oxandrolone or methyltestosterone. These agents increase the level of aminopeptidase P, an enzyme that inactivates kinins; kinins (especially bradykinin) are responsible for the manifestations of<unk> . In 2018, the U.S. Food and Drug Administration approved lanadelumab, an injectable monoclonal antibody, to prevent attacks of HAE types I and II in people over age 12. Lanadelumab inhibits the plasma enzyme kallikrein, which liberates the kinins bradykinin and kallidin from their kininogen precursors and is produced in excess in individuals with HAE types I and II.
Angioedema
Contact dermatitis
Digitalis
Abscess
Venospasm
Anaphylaxis
Lymphedema
Myxedema