Cold urticaria (essentially meaning cold hives) is a disorder in large red welts called hives (urticaria) form on the skin after exposure to a cold stimulus. The hives are usually itchy and often the hands and feet will become itchy and swollen as well. Hives vary in size from about 7 mm in diameter to as big as about 27 mm or larger. This disorder, or perhaps two disorders with the same clinical manifestations, can be inherited (familial cold urticaria) or acquired (primary acquired cold urticaria). The acquired form is most likely to begin between ages 18 and 25, although it can occur as early as 5 years old in some cases. Life-threatening risks include suffocation resulting from swollen tissue (pharyngeal angioedema) induced by cold foods or beverages, drowning after shock from swimming in cold water, and anaphylactic shock. Types
Cold urticaria may be divided into the following types:

Primary cold contact urticaria
Primary cold contact urticaria is a cutaneous condition characterized by wheals, and occurs in rainy, windy weather, and after swimming in cold water and after contact with cold objects, including ice cubes. Secondary cold contact urticaria
Secondary cold contact urticaria is a cutaneous condition characterized by wheals, due to serum abnormalities such as cryoglobulinemia or cryofibrinogenemia are extremely rare, and are then associated with other manifestations such as Raynauds phenomenon or purpura. Reflex cold urticaria
Reflex cold urticaria is a cutaneous condition in which generalized cooling of the body induces widespread welting.
However, commercial antigen tests have a high degree of cross-reactivity with other endemic fungal conditions such as histoplasmosis, and thus cannot distinguish blastomycosis from other similar conditions. This cross-reactivity is caused by these related fungal organisms using similar galactomannans in the cell wall.While culture of the Blastomyces organism remains the definitive diagnostic standard, its slow growing nature can lead to a delay of up to four weeks. In addition, sometimes blood and sputum cultures may not detect blastomycosis. Cultures of the cerebrospinal fluid also have poor sensitivity compared to histopathological examination of the affected tissue. Treatment
Under Infectious Disease Society of America guidelines, severe cases of blastomycosis and cases with central nervous system (CNS) involvement are treated initially with amphotericin B, followed by a lengthy course of an azole drug such as itraconazole. In most cases the amphotericin treatment lasts for 1–2 weeks, but in cases of CNS involvement it may last for up to 6 weeks. Cases that do not require amphotericin B treatment are treated with a lengthy course of an azole drug.Among azole drugs, itraconazole is generally the treatment of choice. Voriconazole is often recommended for CNS blastomycosis cases due to its ability to pass the blood-brain barrier. Other azole drugs that may be used include fluconazole. Ketoconazole was the azole drug first used for blastomycosis treatment, but has been largely replaced by itraconazole because ketoconazole is less effective and less tolerated by patients. The azole treatment generally lasts for a minimum of six months. Cure rates from itraconazole treatment are nearly 95%.