Fig. 1.

Experimental setup. The effect of capsaicin on the responses elicited by 6 different intensities of mechanical pinprick stimulation (16, 32, 64, 128, 256, and 512 mN) was assessed at 2 different time points: before (T0) and 30 min after (T1) intradermal capsaicin injection. The pinprick stimuli were delivered within a 1-cm-wide area defined by 2 circles drawn on the forearm (gray circle), i.e., at a distance ranging between 1.5 and 2.5 cm from the site of capsaicin injection on both the capsaicin-treated arm and the contralateral arm, which served as control.