Cutaneous
pain is a common symptom of
skin disease, and available
therapies are inadequate. We developed a neural selective and
injectable method of cryoneurolysis with
ice slurry, which leads to a long-lasting decrease in mechanical
pain. The aim of this study is to determine whether slurry injection reduces cutaneous
pain without inducing the side effects associated with conventional cryoneurolysis. Using the rat sciatic nerve, we examined the effects of slurry on nerve structure and function in comparison with the effects of a Food and
Drug Administration‒approved cryoneurolysis device (Iovera). Coherent anti-Stokes Raman scattering microscopy and immunofluorescence staining were used to investigate histological effects on the sciatic nerve and on downstream cutaneous nerve fibers. Complete
Freund's Adjuvant model of cutaneous
pain was used to study the effect of the slurry on reducing
pain. Structural changes in myelin induced by slurry were comparable with those induced by Iovera, which uses much colder temperatures. Compared with that of Iovera, the decrease in mechanical
pain due to slurry was less profound but lasted longer without signs of
dysesthesia. Slurry did not cause a reduction of epidermal nerve fibers or a change in thermal
pain sensitivity. Slurry-treated rats showed reduced cutaneous mechanical
pain in response to Complete
Freund's Adjuvant. Slurry injection can be used to successfully reduce cutaneous
pain without causing
dysesthesia.