Non-invasive Diagnosis of Cold Urticaria

ICT was performed following a standard protocol. Briefly, a melting ice cube in thin plastic bag was placed on the volar surface of the patient forearm for 5 min, with macroscopic assessment of the test site 10 min later. TempTest® CSTs were done with TempTest® 4.0 (Courage \& Khazaka, Cologne, Germany), which has a single Peltier element (length: 350 mm, width: 2 mm) that provides a continuous temperature gradient from 4°C to 44°C. The use of TempTest® allows for reproducible and standardized cold (and heat) provocation tests and the identification of CTTs. TempTest® CST results were also assessed 10 min after the end of cold exposure.