What is Acne?
Acne is a disease of the pilosebaceous units (hair follicles and their associated sebaceous glands). Sebaceous glands secrete a thick, fatty material called sebum and patients with high sebum production have a greater risk of developing acne.
P. acnes is a normal human skin bacterium and is the dominant microbe in sebum. If this bacteria overgrows in sebum, it changes the consistency of the material leading to plugging of the duct. This results in a comedone. If the duct opening is closed, the comedone appears white and is referred to as a “whitehead.” If the duct is open, exposing the sebum to the air, the material turns black and is called a “blackhead.”
Frequently, P. acnes also irritates or inflames the lining of the hair follicle. The follicle may become a red and tender bump called a papule. Papules may progress to pustules that have red bases with puss in the center. If the follicle wall ruptures, it can form a large, painful, solid nodule or puss-filled cyst and often lead to scarring.
Acne can be divided into two general types: inflammatory and non-inflammatory. Non-inflammatory acne is limited to “whiteheads” and “blackheads.” Inflammatory acne is classified as mild, moderate or severe based on the number of lesions present and severe inflammatory acne includes cystic acne. Some patients can have both types of acne at the same time.
Adult Acne
Although acne is usually considered a problem for adolescents and young adults, it is also not uncommon for older adults, especially women, to have acne. Adult acne can be troublesome and aggravating because treatments that may have worked as a teen, no longer help and different approaches must be taken.
Women are more likely to get adult acne than men. It can be related to hormonal changes related to the menstrual cycle, menopause, or changing contraceptives. It may also be due to stress or a strong family history of acne.