Conclusions
The TRPV3 activator carvacrol can cause itching if applied over burn scars. This study can help understand the mechanism and prognosis of post-burn itching and contribute to the development of its treatment.
Methods
Design: This was a double-blind clinical trial with non-randomized distribution. Setting: This study was performed in a hospital setting. Patients or participants: Patients with itching of burn scars (numerical rating scale (NRS), <3; n = 8; Group 1 and NRS, ≥3; n = 16, Group 2) and healthy volunteers (n = 18, Group 3) were included. Interventions: The investigational drug carvacrol (100%, 75%, and 50%) and control drug (10% ethanol) were applied over the scars using IQ Ultimate™ 1 × 1 cm chamber sheets. Main variables of interest: The presence of pruritus, erythema, edema, and other skin lesions was evaluated. The verbal NRS scores were also compared.
Results
Carvacrol induced more itching in Group 2 than in Groups 1 and 3. In Group 2, 100%, 75%, and 50% carvacrol caused significantly more itching (NRS score, 5.18 ± 3.04, 5.18 ± 3.04, and 4.93 ± 2.96, respectively) than that in Group 1 (NRS score, 1.00 ± 1.80, 1.00 ± 1.80, and 1.00 ± 1.80, respectively) and Group 3 (NRS score, 2.38 ± 1.94, 1.27 ± 1.32, respectively). Conclusions: The TRPV3 activator carvacrol can cause itching if applied over burn scars. This study can help understand the mechanism and prognosis of post-burn itching and contribute to the development of its treatment.