Acne vulgaris is a cystic condition, an epidermal cyst, which is caused by the blockage of the sebaceous gland’s excretory ducts. The secretions from the glands are not able to be discharged, thus accumulating in the glands for a long time. As more secretions accumulate, the sebaceous glands gradually increase in size and form cysts, also known as comedones. The wall of the cyst is a layer of epithelial cells and a layer of fibrous connective tissue, which is somewhat elastic but also prone to rupture. They are usually as small as a pea grain or as large as an egg, and will rise above the surface of the skin. When touched, the surface is smooth and can be squeezed out to produce a soya bean dregs-like substance. They can be found on the head, face, neck, scrotum and other parts of the body. If the tumor is small and does not affect your life, you can observe it for a while. If the tumor grows fast, the cyst needs to be cut open and the swelling removed. If secondary infection occurs, it can also be treated with oral antibiotics such as cefixime capsules and amoxicillin capsules as prescribed by the doctor. It is recommended that patients with acne should go to the hospital in a timely manner, to clarify the cause of the disease under the guidance of the doctor reasonable treatment.