Strontium nitrate decreased histamine-induced itch magnitude and duration in man.

Previous studies have demonstrated that strontium salts have a potent and broad ability to suppress sensory irritation. To ascertain the possible antipruritic effects of topical strontium salts, we conducted a double-blind randomized study to evaluate the effect of 20% strontium nitrate on itch magnitude (intensity) and duration. In 8 human subjects, strontium nitrate was applied to the volar forearm and vehicle control to the contralateral volar forearm for 30 min; both substances were reapplied for an additional 5 min. Itch was then experimentally induced by intradermal injection of histamine. Itch magnitude was rated each minute for the first 20 min using a visual analogue scale (VAS). Itch duration in minutes was also recorded. Strontium nitrate, in comparison to its vehicle control, significantly shortened itch duration from 28.1+/-5.4 min (mean +/- SEM) to 18.5+/-4.2 min (p<0.01) and reduced itch magnitude at time points 12-20 min and overall (p<0.05). Strontium nitrate may act as a topical antipruritic agent in reducing histamine-mediated itch.