The cause of acne is not the consumption of junk food. Acne is caused when the skin’s hair follicles, or pores, clog. When this happens, sebum (oil) becomes trapped and builds up in the follicle resulting in a pimple or blemish. If left untreated, severe acne can leave deep scars.
Skin continually renews itself by shedding dead skin cells and replacing them with new. Dead skin cells can cause acne by sticking together inside a pore, creating a plug. About two to three weeks after a pore clogs, a pimple forms causing acne.
Sebaceous glands near the skin's surface produce a continual supply of sebum. This oil travels up through the pores, supplying the skin with lubricate to protect it from drying out. When a pore becomes clogged, the body continues to produce oil and send it through the hair follicles. This constant supply of sebum backs up and accumulates behind a plugged pore, which is one cause of acne.
Open comedones (blackheads) result from an enlarged plug pushed through the surface of the skin. They have a dark head, resulting not from dirt, as commonly believed, but a concentration of melanin. Closed comedones (whiteheads) are similar but have stayed below the surface of the skin.
Papules, pustules and nodules are examples of inflammatory acne. When comedones are closed and clogged with oil, it creates an environment in which bacteria begin to multiply rapidly. The body’s response to this intrusion is to send white blood cells to combat the inflammation. This response produces pus in the pimple. This is the cause of acne that appears red, tender and inflamed.
Nodules are large, deep, pus filled lesions resulting from the contents of a comedone spilling into the surrounding skin. This cause of acne is inflamed, making it tender to the touch. If left untreated, nodules can rupture under the skin’s surface leaving scars.
The cause of acne can also be hormonal. The production of the hormone androgen surges during puberty, resulting in enlarged and overactive sebaceous glands. As these oil-producing glands respond to the hormonal changes occurring during adolescence, the skin is most prone to developing the pimples and blemishes that are the cause of acne. The skin on the face, chest and back has the highest number of sebaceous glands and are the areas where acne is most frequently located. Acne is most common in the teenage and young adult years but can present at any time on any part of the skin with hair follicles.