There are three main factors that contribute to the formation of acne:
- Overproduction of oil (sebum)
- Irregular shedding of dead skin cells resulting in irritation of the hair follicles of your skin
- Buildup of bacteria
Acne occurs when the hair follicles (tiny holes in your skin that an individual hair grows out of) become blocked with oil and dead skin cells. Hair follicles are connected to sebaceous glands. These glands produce an oily substance called sebum to lubricate the hair and the skin to stop it drying out. In acne, the glands begin to produce an excess amount of sebum. When the excess sebum mixes with dead skin cells, both substances can build up in the hair follicles and form together as a soft plug.
If the excess oil and dead skin cells clog the pore and block the opening of the pore, the follicle wall will bulge outwards, creating a whitehead. Because the pore closes, dermatologists call this type of acne a “closed comedo.” Alternatively, the plugged follicle may be open to the surface and may darken, causing a blackhead. Dermatologist may call a blackhead an “open comedo”
The excess oil also creates an environment where bacteria (P. acnes) can thrive. As the bacteria multiply in a clogged pore, the pore becomes inflamed. Inflammation is what causes a pimple to look red, hot, and swollen.
Acne cyst is the most severe type of acne. It occurs when inflammation reaches deep into the skin. Cysts can be very painful and may cause permanent scarring after it heals.
There are also certain conditions that can trigger the formation of acne, such as:
- Genetic syndrome in the family
- Hormonal changes — which have the greatest impact on sebum production
- Bacteria infection
- Medications — Drugs containing corticosteroids, androgens or lithium are known to cause acne.
- Extreme stress
- Restless sebaceous glands
- Exposure to harmful chemicals