Excuse me, can I apply for a patent for earthwork for treating skin diseases?

You can declare, but it is not recommended to declare, because the patent policy is that protection is not confidential and confidentiality is not protected, so your patent declaration is public, and it is difficult to determine that this formula is infringing. I suggest you keep it confidential. Our company always receives customers with secret recipes in this way, and only when customers really insist on reporting will they be accepted.