Cold urticaria, or cold contact urticaria, is a subtype of physical urticaria (table 1). It is characterized by pruritic wheals (hives or urticaria) and/or angioedema due to cutaneous mast cell activation and release of proinflammatory mediators after cold exposure. Triggers include cold objects, cold liquids, and cold air. The underlying pathophysiology is largely unknown.
Cold urticaria is reviewed here. Other urticaria disorders, including acute and chronic spontaneous urticaria and other forms of physical urticaria, are discussed separately. (See "Physical urticarias" and "New onset urticaria" and "Chronic urticaria: Standard management and patient education" and "Chronic urticaria: Clinical manifestations, diagnosis, pathogenesis, and natural history".)
The incidence of cold urticaria was estimated to be 0.05 percent in Central Europe . The frequency of cold urticaria among physical urticaria subtypes varies between 5 and 34 percent, partly depending upon the geographic region (ie, higher incidences are found in regions with colder climates and lower rates are seen in regions with a warmer climate) [1-4].
Cold urticaria most frequently affects young adults [3,5]. Both sexes are affected with similar frequency in most studies [1,3,6], although one study reported that females were affected twice as often as males . Up to half of patients with cold urticaria are atopic and one-fourth have other types of inducible urticaria, most commonly symptomatic dermographism and cholinergic urticaria [1,7].
Cold urticaria symptoms result from the activation of mast cells and subsequent release of histamine and other proinflammatory mediators. Following a cold stimulation test, cutaneous mast cells in patients with cold urticaria show signs of degranulation, and serum levels of mast cell mediators are increased [8-10]. This results in pruritus, burning and erythema from activation of skin nerves, and vasodilation of skin vessels with extravasation causing wheals and angioedema.