The cause of acne on the chest may be related to the anatomical structure of the area with dense follicular sebaceous glands. Because of the dense follicular sebaceous glands in this area, and because the patient produces a large amount of sebum, an overproduction of sebum may occur. When the sebaceous glands are active, the secreted cortex cannot be excluded from the skin surface, and closed acne, or whiteheads, may form. In some cases, this acne may be secondary to a localized pathogenic infection, such as Propionibacterium acnes infection, which may lead to inflammation. It is also possible that some endocrine dysfunction, or improper diet, as well as overexertion of the patient, or scratching, may cause acne to appear in the area. Of course, there is also the possibility of an infection in the area, such as infectious molluscum contagiosum due to infection with the molluscum contagiosum virus, but some people may mistake it for a common pimple.