Control patch will be the same topical solution but will not contain capsaicin. The patch will applied to the hand for 30 - 60 min. Patients will be instructed to not touch or wash their hands during the course of the study to minimize spreading of the patch to other areas of the body. Subsequently, the patch will be immediately removed.

8% capsaicin topical patch or 0.1% capsaicin cream. The patch will applied to the hand for 30 - 60 min. The cream will be applied similarly on a 3 cm2 area of the arm. Patients will be instructed to not touch or wash their hands during the course of the study to minimize spreading of the patch to other areas of the body. Subsequently, the patch will be immediately removed.

0.1 ml of 8% capsaicin topical patch or 0.1% capsaicin cream

A Peltier device (Pathway, Medoc) will be used to tap the skin surface with a 3 cm x 3 cm probe. The Peltier device will be used to provide very brief, repetitive, thermal stimuli (for approx. 1s) to the skin using computer controlled temperatures. Heat stimuli at intervals of 2.5 sec produce sensations of increasing pain (temporal summation), depending on the number of stimuli presented. The late sensations of warmth are delayed in onset by approximately 1.5 sec after the probe touches the skin, because the sensation depends upon stimulation of slowly conducting unmyelinated peripheral afferents.