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

Background: Previous studies have demonstrated that strontium salts have a potent and broad ability to suppress sensory irritation. Objective: To asce rtain the possible antipruritic effects of topical strontium salts, we cond ucted a double-blind randomized study to evaluate the effect of 20% stronti um nitrate on itch magnitude (intensity) and duration. Methods: In 8 human subjects, strontium nitrate was applied to the volar forearm and vehicle co ntrol to the contralateral volar forearm for 30 min; both substances were r eapplied for an additional 5 min. Itch was then experimentally induced by i ntradermal injection of histamine. Itch magnitude was rated each minute for the first 20 min using a visual analogue scale (VAS). Itch duration in min utes was also recorded. Results: Strontium nitrate, in comparison to its ve hicle 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). Conclusion: Strontium nitrat e may act as a topical antipruritic agent in reducing histamine-mediated it ch. Copyright (C) 2000 S. Karger AG,Basel.