Tolerance and Performance of Cyto-selective Difluoroethane-based Cryotherapy in the Treatment of Brown Spots.

CS5_3 aims to evaluate the tolerance and to adjust the mode of administration of 4 different conditions of cryotherapy treatments applied on the brown spots of the face and hands with 3 prototypes. A brown spot is defined as solar or senile lentigo and post-inflammatory hyperpigmentation (PIH).Each treatment corresponds to a combination of a specific sequence of a cryogenic spray and of a frequency of application.The study will evaluate 3 prototypes :Prototype 1 : SN from (816-v1 001) to (816-v1 100)Prototype 2 : SN from (816-v1 101) to (816-v1 150)Prototype 3 : SN from (816-v1 151) to (816-v1 200)Prototypes will be applied on the face and hands according to specific frequencies of application.

Inclusion Criteria:Female or male.Ages 18 to 75.Phototypes V and VI (according with Fitzpatrick scale), according to the spots distribution table.Featuring brown spots ≥ 3 and ≤ 6 mm in diameter on the face (and if possible, on the hands).Agreeing not to be exposed to the sun (or artificial UV) during the study.Informed, having undergone a general clinical examination attesting to his/her ability to participate in the study.Having given written consent for their participation in the study.No suspicion of carcinoma after investigation by a dermatologist.Exclusion Criteria:Having performed cosmetic treatments (exfoliants, scrubs or self-tanners, manicures (only nails care acceptable), facials, UV ...) in the month before the start of the study, on the face and/or hands.Having applied a depilatory product in the month prior to the start of the study, on the face and/or hands.Having performed cosmetic treatments in a dermatologist (laser, intense pulse light, peeling, creams, cryotherapy ...), on the face and/or hands in the last 6 months.With dermatosis, autoimmune disease, systemic, chronic, or acute disease, or any other pathology that may interfere with treatment or influence the results of the study (people with diabetes or circulatory problems, allergic to cold, Raynaud's syndrome...).Receiving treatment by general or local (dermo corticoids, corticosteroids, diuretics ...) likely to interfere with the evaluation of the parameter studied.Participating in another study or being on a period of exclusion from a previous study.Unable to follow the requirements of the protocol.Vulnerable: whose ability or freedom to give or refuse consent is limited.Major protected by law (tutorship, curatorship, safeguarding justice...).People unable to read and write English language.Unable to be contacted urgently over the phone.For female subjects:Pregnant woman (or wishing to be pregnant during study) or while breastfeeding.A woman who does not have a contraceptive method.