A randomized, double‐blinded, vehicle‐controlled clinical trial of topical cryosim‐1, a synthetic TRPM8 agonist, in prurigo nodularis

Background Prurigo nodularis (PN) is an intensively pruritic skin disease that negatively influences quality of life. Cryosim‐1 (Intrinsic IB Spot) is a synthetic, selective transient receptor potential melastatin 8 agonist. Aims To investigate the efficacy and safety of cryosim‐1 in PN patients. Patients/Methods A randomized, double‐blinded, placebo‐controlled clinical trial including 30 patients was conducted. The numerical rating scale (NRS) of pruritus was evaluated before and 2 h after cryosim‐1 application at every visit. Results At week 8, the mean pruritus NRS before serum application (4.7 ± 0.4 treatment, 6.1 ± 0.5 placebo; p = 0.045) and 2 h after serum application (2.8 ± 0.4 treatment, 4.3 ± 0.5 placebo; p = 0.031) were significantly lower in the treatment group, and the mean NRS for sleep disorder was significantly lower in the treatment group (2.2 ± 0.5 treatment, 4.2 ± 0.8 placebo; p = 0.031). The mean satisfaction scales for pruritus improvement were significantly higher in the treatment group (7.2 ± 0.6) than in the placebo group (4.0 ± 0.9; p = 0.005). There was no difference in TEWL between the two groups, and no adverse reactions were reported. Conclusions Cryosim‐1 is a safe and effective topical treatment for PN patients.