Cold urticaria is a skin condition in which exposure to cold can trigger an abnormal reaction. Its exact cause is often unknown, although it has been associated with certain infections and blood conditions. A familial form also exists and has been linked to a specific chromosome, although most cases are not inherited.

Symptoms can develop after exposure to cold air or cold water and may include redness, itching, burning, and raised welts or hives. In some cases, people may also experience tiredness, anxiety, fever, or fainting. Acquired cold urticaria can appear within minutes and typically lasts for a few hours, while familial forms may take longer to develop and can persist for much longer.

Treatment depends on the individual and the severity of symptoms. Antihistamines such as Claritin and Zyrtec may help relieve mild reactions by reducing the effects of histamine. Other treatments mentioned in the source include systemic corticosteroids and dapsone, but these should only be considered with appropriate medical guidance. Anyone experiencing symptoms or reactions to cold should consult a healthcare professional for proper evaluation and treatment.