RESUMEN
Acquired cold urticaria (ACU) is a subtype of physical urticaria which may be primary (idiopathic) or secondary to underlying infections or cryoproteins. In addition to complete history and thorough physical examination, the diagnosis is dependent on a positive cold stimulation time test (CSTT) which is the minimum time of cold contact stimulation required to induce an immediate coalescent wheal. Although idiopathic type is seen in 96% of the cases, it is important to rule out cryoprotein by an intricate yet simple test for cryoprecipitate. The identification of cold exposure as the likely trigger for urticaria is vital because systemic anaphylactic reactions are common in patients with cold urticaria, occurring in roughly 1 in 3 patients. In addition to preventive counseling and avoidance of critical cold exposure, H1-receptor antagonists form the first line of treatment. However resistant cases may require cyclosporine, danazol or omalizumab. No individual case reports of ACU appear in Indian literature. Therefore, the authors attempt to highlight the diagnostic work-up and therapeutic options for this not so uncommon cause of chronic urticaria.