When sloughed-off skin cells, excessive sebum and bacteria plug pores, acne is the result, according to the University of Maryland Medical Center. Whiteheads are a form of acne in which the pores are blocked by skin cells. Blackheads are plugged pores that are exposed to the air, oxidizing the surface of the plug. Pimples, pustules and cysts are plugged pores that become infected. Malodorous acne isn't a common problem, although the discharge from blocked pores may have a little odor.
Generally, sebum moves toward the surface of the skin and acts as an emollient to preserve moisture and prevent the movement of microbes and chemicals through the skin into the body. But excessive sebum production, combined with dead skin cells, can block your pores. Occasionally it can develop the kind of odor your scalp may have.
Dead Skin Cells
As new skin cells develop in the dermis, older skin cells are pushed out. The outermost layer of skin cells, the stratum corneum, consists of about 20 layers of dead skin cells that gradually slough off. But in acne, dead skin cells can become trapped in pores, and instead of sloughing off, they form a plug with the sebum. They can begin to decay in the pores, contributing to the odor problem.
Bacteria is normally present on the skin, and some of it is beneficial. But harmful bacteria, such as Staphylococcus aureus, can also be present on the skin. Blocked pores provide a feeding ground for the bacteria and can become infected as bacteria attack the materials in the pore. The odor isn't likely to be very noticeable. If it is very noticeable, it may indicate a more serious infection, and you should see your physician, according to New York University's Langone Medical Center.
Picking and Squeezing Acne
Picking and squeezing whiteheads, blackheads and pimples introduces dirt and more bacteria into the pores, which can worsen any odor. Bacteria can be transferred from infected pimples to blackheads or whiteheads that were not previously infected, spreading infection across the face or any other area.
Acne isn't caused by a lack of cleanliness. But washing your face twice a day with a gentle cleanser helps to remove bacteria and dirt. The less you touch your face, the less likely you are to introduce bacteria and dirt into your pores. Washing your hair and cleansing your face after taking off a sweaty headband or scarf helps to keep clogged pores clean. Taking a shower after taking off sweaty clothing can help prevent acne on your back, chest and shoulders. Good skin care makes it less likely that your acne will develop an odor.