The main reason for the formation of acne vulgaris may be directly related to the dense distribution of sebaceous glands in the hair follicles in the area. Under certain triggering conditions, sebaceous glands may secrete a large amount of sebum, and if this sebum gathers inside the sebaceous ducts, it may cause a certain amount of swelling, so that the walls of the ducts may rupture and form secondary inflammation and infection, so that acne may form. The inflammatory pimples are formed because of trauma, especially when someone squeezes the area with their hands. It can also be related to viral infections, such as the formation of infectious molluscum contagiosum.