Short-Term Alternating Temperature Enhances Histamine-Induced Itch: A Biphasic Stimulus Model  Florian Pfab, Michael Valet, Till Sprenger, Thomas R. Toelle, Georgios I. Athanasiadis, Heidrun Behrendt, Johannes Ring, Ulf Darsow  Journal of Investigative Dermatology  Volume 126, Issue 12, Pages 2673-2678 (December 2006) DOI: 10.1038/sj.jid.5700577 Copyright © 2006 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 1 Mean itch intensity (VAS) of all volunteers (n=9) of the two sessions (green: first session; violet: second session) rated every 4 seconds. The 14 cycles (each lasting 43seconds, beginning with a 21.5 seconds 32°C block (red background) and ending with a 21.5-second 25°C block (blue background)) are separated by the black gridlines. The yellow line represents the scratch threshold (33% itch intensity). Journal of Investigative Dermatology 2006 126, 2673-2678DOI: (10.1038/sj.jid.5700577) Copyright © 2006 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 2 Showing one cycle: Mean itch intensity (VAS) of both sessions of all volunteers at the various temperature intervals. As indicated by the dotted line, the red columns numbered 1–5 indicate 32°C temperature intervals, whereas the blue columns numbered 6–10 mark 25°C temperature intervals, each lasting 4seconds. The yellow line represents the scratch threshold (33% itch intensity). Asterisks indicate significant differences between intervals. **P<0.01, ***P<0.001. Journal of Investigative Dermatology 2006 126, 2673-2678DOI: (10.1038/sj.jid.5700577) Copyright © 2006 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 3 Item rating of the EIQ. The red line represents neutral temperature blocks (32°C), whereas the blue line represents relative short-term cold temperature blocks (25°C). The asterisks indicate significant differences (*P<0.01) between blocks. (a) Descriptive items. (b) Emotional items. Journal of Investigative Dermatology 2006 126, 2673-2678DOI: (10.1038/sj.jid.5700577) Copyright © 2006 The Society for Investigative Dermatology, Inc Terms and Conditions