Melasma is a refractory skin disease due to its complex pathogenesis and difficult treatment. Studies have found that human umbilical cord mesenchymal stem cell-derived exosomes (hUCMSC-Exos) could serve as a novel cell-free therapeutic strategy in regenerative and aesthetic medicine. It could potentially treat melasma, but the skin barrier is a challenge. This study aims to explore the safety and efficacy of hUCMSC-Exos in the treatment of melasma and means to promote its percutaneous penetration.

80 patients with melasma treated in our department were divided into four groups. 1565 nm nonablative fractional laser (NAFL) combined with normal saline treatment group was used for Group A. Microneedle，NAFL，a plasma named Peninsula Blue Aurora Shumin Master (PBASM) combined with hUCMSC-Exos were used for the other treatment groups (B, C, and D, respectively). The treatment was given four times with an interval of one month. The degree of pain post-treatment, MASI, improvement rate, physician global assessment score, satisfaction and complications after treatment were evaluated six months later.

Inclusion Criteria:

- Patients diagnosed with chloasma who meet the clinical diagnostic standards and efficacy standards (revised version) of chloasma and have skin lesions on the face.

It is hoped that exosomes combined with 1565 non-ablative fractional laser, blue aurora or micro-needle can improve facial chloasma.

Fully understand and understand the content and significance of this study, implementation plan, possible benefits, risks and countermeasures, rights and obligations of subjects (including privacy protection, free withdrawal), willing to participate in this clinical study and able to cooperate well, Those who signed the informed consent form.

Exclude post-inflammatory pigmentation, malar brown-green nevus, Riehl's melanosis, pigmented lichen planus and other skin diseases.

Subjects who agree not to use other cosmetic treatments related to the study during the study period.

Exclusion Criteria:

1. Patients who refuse to sign the informed consent form to participate in the trial;
2. Those with a history of important organ diseases, or a history of autoimmune diseases or immune dysfunction;
3. Abnormal coagulation function, current use of anticoagulants, thrombophilia and history of familial genetic diseases;
4. Pregnant or lactating women;
5. Patients taking oral contraceptives or hormone replacement therapy during the study period or within the past 12 months;
6. Patients with scar constitution;
7. Active skin infection;
8. Those who have a history of multiple severe allergies, a history of hereditary allergies, photosensitivity or photosensitivity drugs, such as sulfa drugs and tetracyclines, those who are allergic to local anesthetics and those who are allergic to lidocaine components, and those who plan to undergo detoxification during the study Allergy healer;
9. History of post-inflammatory pigmentation;
10. Those who have received treatment for chloasma in the past;
11. Those who have undergone chemical peeling, dermabrasion or other skin resurfacing on their face in the past;
12. Patients who are participating in other clinical studies;
13. Other reasons that the researcher considers unsuitable for clinical investigators.