A novel topical formulation containing strontium chloride significantly reduces
the intensity and duration of cowhage-induced itch.
Author(s): Papoiu AD(1), Valdes-Rodriguez R, Nattkemper LA, Chan YH, Hahn GS, Yosipovitch G.
Affiliation(s): Author information:
(1)Department of Dermatology, School of Medicine, Wake Forest University Health
Sciences, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
Publication date & source: 2013, Acta Derm Venereol. , 93(5):520-6
The aim of this double-blinded, vehicle-controlled study was to test the
antipruritic efficacy of topical strontium to relieve a nonhistaminergic form of
itch that would be clinically relevant for chronic pruritic diseases. Itch
induced with cowhage is mediated by PAR2 receptors which are considered to play a
major role in itch of atopic dermatitis and possibly other acute and chronic
pruritic conditions. The topical strontium hydrogel formulation (TriCalmĀ®) was
tested in a head-to-head comparison with 2 common topical formulations marketed
as antipruritics: hydrocortisone and diphenhydramine, for their ability to
relieve cowhage-induced itch. Topically-applied strontium salts were previously
found to be effective for reducing histamine-induced and IgE-mediated itch in
humans. However, histamine is not considered the critical mediator in the
majority of skin diseases presenting with chronic pruritus. The current study
enrolled 32 healthy subjects in which itch was induced with cowhage before and
after skin treatment with a gel containing 4% SrCl2, control vehicle, topical 1%
hydrocortisone and topical 2% diphenhydramine. Strontium significantly reduced
the peak intensity and duration of cowhage-induced itch when compared to the
control itch curve, and was significantly superior to the other two
over-the-counter antipruritic agents and its own vehicle in antipruritic effect.
We hereby show that a 4% topical strontium formulation has a robust antipruritic
effect, not only against histamine-mediated itch, but also for non-histaminergic
pruritus induced via the PAR2 pathway, using cowhage.
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