If the skin surface has visible raised bumps and a white, foul-smelling substance can be squeezed out from the inside, it is considered to be a simple sebaceous cyst. This condition is caused by the excessive secretion of sebaceous glands inside the epidermis and the blockage at the top of the hair follicle due to excessive secretion, and a large amount of secreted sebum accumulates inside the hair follicle and gradually expands to the surrounding area, thus causing a benign skin proliferation. The pain is not painful, but some people can feel the pressure and pain when they touch it. If you want to get rid of it, simply using topical medication is not effective, you can choose surgical treatment, the entire subcutaneous cystic changes are removed, after the complete removal of the envelope, you can avoid recurrence to the maximum extent.