Acne occurs in areas where the density of active sebaceous glands is the highest, a reason why it is usually found on our face, back, chest, and upper arms, though may extend to the buttock in some cases.
It is known that one of the sebaceous lipid composition called “Triglycerides,” and that some of the Triglycerides in the sebum will convert to free fatty acids by P. acnes (a bacterium) that helps create an environment for P. acnes to grow and flourish. Another lipid composition with the named of “Squalene,” and certain free fatty acids also play an important role in the causation of acne. Unfortunately, the sebum of people with acne has relatively little linoleic acid (a kind of free fatty acid), which is vital for our skin to slough off properly.
We can think of acne lesion as one large scale existing inside the follicle, and that people with acne will have larger sebaceous glands that make them produce even more sebum, as a consequence this will dilute the linoleic acid in the follicle, thus disrupt our normal skin sloughing and lead to the formation of mirocomedo. It is good to know that excess sebum production is mainly due to the differences of pilosebaceous unit (i.e. the grouping that containing the hair follicle and the attached sebaceous gland) to the local environment or the circulating of androgens (i.e. a class of hormones that can cause the sebaceous gland to enlarge and produce more sebum), or both.
For people who are prone to acne, the overall size of the sebaceous gland will increase and become lumpier in response to an increased in production of androgens which at the same time caused an increased in the secretion of sebaceous oils, i.e. sebum. This may happen even when we are at the age of 7 to 9. It is noted that women with no measurable abnormalities in hormone levels often find their acne improves when they take oral contraceptives.
In fact, the hormonal changes at puberty will lead to changes in both the sebaceous glands and our skin cells lining the hair follicle opening (i.e. pore). We may notice that some people are more affected by hormones than others; this is because there are factors that control how sebaceous glands handle our hormone, a factor of heredity (i.e. the traits that we get from our parents, such as the tendency to height, hair color, acne, etc).
Therefore, acne care and acne clear need to be addressed from several different angles to achieve better acne control and acne solutions.