Synonyms

	▪	Wheals–hives, nettle rash
	▪	Angioedema–Quincke edema

	▪	Urticaria is characterized by transient skin or mucosal swellings due to plasma leakage. Superficial dermal swellings are wheals, and deep swellings of the skin or mucosa are termed angioedema. Wheals are characteristically pruritic and pink or pale in the center, whereas angioedema is often painful, less well defined and shows no color change.
	▪	There are several recognizable clinical patterns of urticaria and different causes. The latter include allergy, autoimmunity, drugs, dietary pseudoallergens, and infections. Many cases remain unexplained (‘idiopathic’) even after full evaluation. C1 esterase inhibitor deficiency needs to be considered as a cause of recurrent angioedema without wheals.
	▪	Diagnosis is based primarily on the history and is supported by investigations, including blood tests, physical and …