Urticaria and Angio-Oedema

Abstract

The term urticaria (also known as ‘hives’ or ‘nettle rash’) is widely used to describe a superficial swelling of the epidermis and mucous membranes that results in a red, raised, itchy rash that can be localized or generalized. This rash is described as weals. The rash may be localized or generalized and acute or chronic. Most patients with urticaria do not have systemic reactions, but allergic urticaria and some physical urticarias may occasionally progress to anaphylaxis. However, urticaria is often a feature of anaphylactic reactions. Angio-oedema is a deeper form of urticaria with swelling in the dermis and submucosal or subcutaneous tissues. It may occur alone, or concurrently with urticaria, affecting up to 50% of patients with chronic urticaria.