[Clinical aspects and diagnostics of mast cell-mediated angioedemas]

Angioedema is defined as transient swelling of the skin and/or mucous membranes. Based on the underlying mediator, angioedema is essentially classified as either mast cell-mediated or bradykinin-mediated. In general, mast cell-mediated angioedema is of shorter duration (1-3 days) and responds to antihistamines, corticosteroids and adrenaline, whereas swelling associated with bradykinin-mediated angioedema typically persists longer and does not respond to histamine-targeted drugs. Mast cell-mediated angioedema includes swelling occurring as part of allergic (IgE-mediated) or pseudoallergic (non-IgE-mediated) reactions, such as those observed in anaphylaxis or intolerance to analgesics. The diagnostic evaluation comprises a detailed medical history, measurement of specific IgE antibodies and/or skin prick testing, as well as provocation testing when indicated. Mast cell-mediated angioedema frequently occurs in association with chronic spontaneous urticaria (CSU), in which approximately 10% of patients can present with isolated angioedema without wheals as well as with chronic inducible urticaria (CIndU). The diagnostic work-up follows current recommendations for chronic urticaria and includes a thorough medical history, physical examination (potentially supported by review of photographic documentation) and basic laboratory investigations, including a differential blood count, C‑reactive protein (CRP), total IgE, and IgG anti-thyroid peroxidase (anti-TPO) antibodies. In the routine clinical practice, in both emergency settings and during the elective evaluation of patients with angioedema, it is essential to be familiar with the characteristic clinical features, differential diagnoses and diagnostic approaches of the various forms of mast cell-mediated angioedema.