The white particles squeezed out of acne are called whiteheads, also known as closed acne, which is actually a type of acne. It is formed when the opening of the sebaceous gland of the hair follicle is blocked by the body’s metabolized keratinocytes or skin secretions, and these keratinized materials and sebum do not communicate with the outside world. The disease is mainly found on the face, but it can also appear on the chest and back. It is a small subcutaneous sebaceous plug, the size of a small grain of rice, usually in the form of a hemispherical white sachet, which is hard to the touch and usually has no symptoms. However, with changes in the body’s internal environment, or under the influence of diet and rest, it can further develop into inflammatory papules, pustules, and other clinical manifestations of acne.