Acne Science

Acne is a complex disease. The Acne Science section covers a range of scientific topics related to the development of acne and the available treatments. For more discussions about common acne questions, refer to our Frequently Asked Acne Questions page.

What Causes Acne?

Acne is a complex disease and many factors can contribute to the development of acne symptoms. Every case of acne is unique and the blend of factors that cause acne varies between individuals. This section contains a list and discussion about the factors that are major contributors to the development of acne symptoms.

Acne at a Cellular Level

Most people can recognize acne when it presents on the face or body. Most people also have the vague understanding that acne is associated with oily skin and an excess production of sebum. But beyond that, few people really grasp what is actually happening at the microscopic level of a pimple. This section discusses the formation of acne lesions at a microscopic level.

The Sebaceous Glands

Sebaceous glands produce and secrete sebum, which is responsible for moisturizing and protecting skin and hair. Sebaceous glands are essential components of healthy skin. Damaged or malfunctioning sebaceous glands contribute to many dermatological conditions, including acne vulgaris. This section discusses the structure and function of the sebaceous glands.


Sebum is a naturally occurring substance that moisturizes, lubricates and protects the skin and hair. Sebum is produced by the sebaceous glands of mammals. Healthy sebum production is essential for the integrity and normal function of the skin as a protective organ. Sebum is also an important source of energy (food) for acne-causing Propionibacterium acnes bacteria. This section discusses the biology of sebum and its role in the development of acne symptoms.

What is Propionibacterium acnes?

Propionibacterium acnes (P. acnes) is a bacteria that can colonize the the skin and hair follicles. Excessive growth of this bacteria in the skin contributes to acne vulgaris. Propionibacterium acnes (P. acnes) is a bacteria that grows deep inside of pores, where it feeds on the sebum that is produced by the sebaceous glands that surround the base of the hair shaft.

Most individuals with acne symptoms have an overgrowth of P. acnes bacteria in their skin. Several research studies have indicated that specific strains of P. acnes bacteria are commonly associated with acne vulgaris. This section details what P. acnes bacteria are and how it contributes to acne symptoms.

The Antibiotic Susceptibility of Propionibacterium acnes

Propionibacterium acnes is a bacteria that grows within hair follicles and contributes to acne symptoms. Antibiotics reduce the growth of acne-causing bacteria and are a common treatment for acne symptoms.

For the past 50 years, physicians and researchers have been screening the susceptibility of Propionibacterium acnes (P. acnes) bacteria to different antibiotics. The results from these studies clearly demonstrate that in many places, P. acnes bacteria are becoming increasingly resistant to certain classes of antibiotics. This section discusses the results of research studies about the antibiotic sensitivity of P. acnes bacteria.

The Antibiotic Families

There are many different families of antibiotics. Each antibiotic family targets bacteria in a unique way. Each antibiotic family tends to be more effective against certain types of bacteria, and less effective against others.

Antibiotics from several different families are used for the treatment of acne. Antibiotics can be used applied topically or ingested orally. The route of delivery, the ability of an antibiotic to accumulate in the skin and the susceptibility of P. acnes bacteria to an antibiotic all impact the efficacy of a given antibiotic treatment. This section discusses the different classes of antibiotics that are used in the treatment of acne.

How Do Bacteria Become Resistant to Antibiotics?

Bacteria can become resistant to antibiotics that they were susceptible to in the past. There are several factors which contribute to the growing problem of antibiotic-resistant bacteria. This section discusses the many ways that antibiotic resistance may occur, as well as the conditions and environments that promote the development of antibiotic-resistant bacteria.

The Antibacterial Activity of Essential Oil

Many essential oils and other plant extracts have antimicrobial properties which can be helpful for health and wellness applications. There is an incredible diversity of essential oils and other plant extracts available on the market today.

Essential Oils are widely used by both professional and casual practitioners of Naturopathic medicine. Essential oils are used to treat many health problems, including acne. This section discusses the scientific research into the antibacterial properties of plant essential oils.

Avoiding Negative Interactions Between Medications

A medication is contraindicated when there is an existing condition that makes its use inadvisable. Certain medications can be contraindicated in specific groups of people (eg. pregnant women) or in combination with other medications (eg. aspirin and warfarin). Basically, some medications are contraindicated with one another because taking them together is known to cause potentially serious problems. This section discusses how to learn more about medications and avoid negative drug interactions.

How Do Acne Scars Form?

Acne scars are the result of tissue damage caused by inflammatory acne. The vast majority of acne scars are caused by from persistent cases of inflammatory acne affecting the same area of skin.

Individuals who suffer from frequent nodular and cystic acne outbreaks (Acne Types: 3-4) are at a very high risk of developing permanent acne scarring. This is particularly true when a region is affected by overlapping acne outbreaks, with no opportunity for the skin to completely heal between outbreaks. This section discusses the different factors that contribute to the development of acne scars.