Acne 101: Types, Causes, Treatments, Tips and More

• Acne happens when skin follicles are blocked with oils and debris compounded with bacterial products and inflammation.
• Acne causes blackheads, whiteheads, pimples, and inflamed nodules and cysts.
• Inflammatory acne is more severe than non-inflammatory acne and it can cause scarring.
• With proper treatment, most people can overcome acne.
• Lifestyle modifications can help improve the condition.

Acne is the most common skin problem in the United States and it affects up to 90% of adolescents at some point. The psychological and social impacts of acne can be severe and are hard to quantify. Without treatment, acne can cause significant and long-lasting skin damage.

What Is Acne? 

Acne vulgaris is a common skin disease that results when oils, skin cells, and other debris accumulate in the hair follicle. Inflammation and the overgrowth of certain types of bacteria have a role in acne development.

Acne is most commonly seen in teenagers and young adults but can affect people of all ages. The face, neck, chest, upper back, and upper arms are frequently affected.

Mild acne manifests as noninflamed lesions with no or few inflamed pimples, while severe acne is characterized by inflamed cysts and nodules.

Diagnosis

The diagnosis of acne is relatively straightforward and laboratory tests are not necessary in most cases. However, some conditions can mimic acne by producing acne-like skin lesions. 

Conditions that can resemble acne include:

• Rosacea is a condition that causes redness and may be associated with papules or pustules on the face. Unlike acne, rosacea does not cause comedones.
• Perioral dermatitis can cause grouped red papules to appear around the mouth.
• Folliculitis is an infection of hair follicles that can resemble inflamed acne lesions. It is more common on the neck, armpits, and legs.
• Drug-induced acne can be a side effect of some medications like steroids and hormonal contraceptives.

Types of Acne

The two main types of acne vulgaris, inflammatory and non-inflammatory, represent the spectrum of the disease. Inflammatory acne is the more severe form.

Non-Inflammatory acne

Non-inflammatory or comedonal acne occurs when sebum and dead skin cells accumulate in the pilosebaceous unit (the hair follicles and associated oil glands). Comedones can be closed (whiteheads) or open (blackheads).

Microcomedones

When sebum and keratin start to clog skin pores, microcomedones (small plugged pore) form. Microcomedones are considered the initial acne lesion and are typically not visible.

Closed comedones or whiteheads

When microcomedones enlarge, they become closed comedones or whiteheads. They have white centers and may have hair growing out of them. Since they do not contain pus or fluid, whiteheads should not be popped.

Open comedones or blackheads 

With continued expansion, a whitehead can open up, exposing the material inside and turning it into a blackhead or open comedone. Oxidization of cellular debris and fats and accumulation of dead cells and the pigment melanin are responsible for the dark color of open comedones.

Inflammatory acne

The development of acne involves colonization by bacteria, which can stimulate the immune system to mount an inflammatory response. The degree of inflammation correlates with the severity of inflammatory acne lesions.

Papules

Papules are the earliest inflammatory lesion and they develop when a comedo develops inflammation. They are raised, tender, small bumps that are pink to red in color.

Pustules

Pustules are large, painful bumps on the skin that contain pus. A pustule’s center is white or yellowish due to the pus and it can be surrounded by swelling and redness. 

Pimples

Pimples are not a separate type of acne lesion–the word “pimple” is a generic term for small inflammatory lesions. Papules and pustules are often referred to as pimples.

Nodules

When bacteria, debris, and inflammatory cells leak into the surrounding skin from a ruptured follicle, a nodule forms. Nodules are highly inflamed, deep-seated lumps that are painful and hard to the touch.

Cysts

Cysts are severely inflamed lesions that contain large amounts of pus. They can be white or red in color and are painful and soft to the touch. When cysts occur along with nodules, it is termed nodulocystic acne. 

Nodulocystic and cystic acne are the most severe types of acne, making them the most likely acne lesions to cause skin scarring. 

Acne Causes

The main factors that cause acne are increased sebum production, hormonal factors, bacterial colonization, and inflammation.

Sebum is an oily material secreted from sebaceous glands that are located around the hair follicles. Excessive sebum accumulation provides a nutrient-rich environment for bacteria to grow. This bacteria is called Cutibacterium acnes (C. acnes; formerly P. acnes), and when it accumulates in a pore, it causes the development of inflammatory acne. 

The presence of bacteria alone can trigger the immune system to cause inflammation. Inflammation causes acne to worsen and further damages the skin. 

Hormones also play a part. Androgens are a group of hormones secreted by the testicles, ovaries, adrenal glands, and fat cells. Shifts in these hormones can stimulate sebum production and contribute to the development of acne. Conditions with androgen excess such as polycystic ovarian syndrome (a large number of abnormal cysts in the ovaries) can also predispose to acne.

Risk Factors

Several risk factors can contribute to the development and severity of acne. These factors cannot cause acne on their own but can worsen the condition.

Genetics

Studies show that people with first-degree family members who suffered from acne have more than a three-fold higher risk of getting it than people without affected family members. This suggests that inheritance plays a strong role in the development of acne.

Diet

Diets with high glycemic load (low nutritional value and high carbs such as sweetened beverages, white rice, and french fries) have been linked to acne worsening.

Although many people believe that chocolate worsens acne, a clear link has not been established.

Smoking

Smokers are more likely to develop acne and to experience worse forms of acne. A dose-dependent relationship also exists, which means that the more cigarettes a person smokes, the higher their likelihood of getting or worsening of acne.

Stress

Emotional stress can contribute to worsening the severity of acne.

Can Acne be Cured?

Technically, acne cannot be cured because the underlying factors that caused it will remain after treatment. However, in the majority of cases, acne can be treated successfully using one or more of the available acne treatments. 

Acne most commonly develops in adolescence and only 12-14% of cases persist into adulthood. 

Acne Treatments

Treatment options for acne include topical treatments, oral medications, and some specialized medical devices. The American Academy of Dermatology recommends combining more than one treatment agent to optimize acne treatment.

Over the counter topicals

Topical acne treatments that you can buy without a prescription include benzoyl peroxide, salicylic acid, alpha-hydroxy acids, and sulfur.

Benzoyl peroxide is a topical medication with antibacterial properties and the ability to break down comedones. It can strip away excess sebum and dead skin cells.

Salicylic acid is a lipid-soluble agent, which means that it can penetrate deep into the follicles. By slowing down the shedding of dead skin cells, it can unclog pores and improve comedones.

Alpha-hydroxy acids like glycolic acid are popular anti-aging treatments for the skin. Glycolic acid and lactic acid can improve acne by reducing dead skin cell shedding and fighting skin color changes that may occur due to inflammation.

Although sulfur has been used in acne treatment for years, the evidence that supports its effectiveness is relatively weak. It is often combined with other medications like benzoyl peroxide and sulfacetamide. Sulfur is thought to work by removing dead skin cells and inhibiting the replication of C. acnes bacteria.

Prescription topicals

Topical acne medications that you need a doctor’s prescription to buy include topical retinoids, topical antibiotics, and azelaic acid.

Retinoids like isotretinoin are derivatives of vitamin A that can decrease skin cell shedding, unclog pores, prevent microcomedone formation, and counteract inflammation. Prescription topical retinoids available in the United States include tretinoin (0.02-0.08%), tazarotene (0.05-0.1%), and adapalene 0.3%. Adapalene 0.1% gel (Differin) can be purchased without a prescription. 

Antibiotics can kill or inhibit the growth of C. acnes, the acne-causing bacteria. 

Azelaic acid has comedolytic (breaking down comedones), antimicrobial, and anti-inflammatory properties. Azelaic acid is available in 15% and 20% concentrations but only the 20% form is FDA-approved for acne treatment.

Oral isotretinoin

Oral isotretinoin is a prescription-only retinoid that is reserved for severe acne or acne that is resistant to treatment. It works by decreasing sebum production, inhibiting C. acnes, and reducing inflammation.

Treatment with isotretinoin for three to four months can produce a 60-95% reduction in inflammatory lesions in patients with severe acne. Oral isotretinoin is available in the form of capsules containing 8 to 40 mg each.

Antibiotics

Antibiotics are integral components of acne treatment regimens. Antibiotics work against the bacterial component of acne and some of them have anti-inflammatory properties. Both topical and oral antibiotics are effective in treating acne.

Antibiotics are applied to areas with acne lesions or taken by mouth once or twice daily. They are typically prescribed for three to four months initially, after which your dermatologist will evaluate whether you should continue using them.

Topical acne antibiotics include clindamycin, erythromycin, dapsone, minocycline, and sulfacetamide. Oral antibiotics include tetracyclines (e.g., doxycycline), macrolides (e.g., erythromycin and azithromycin), trimethoprim-sulfamethoxazole, and amoxicillin.

Professional treatments 

Professional office-based treatments for acne include photodynamic therapy, chemical peels, microdermabrasion, and extraction of comedones.

Photodynamic therapy involves the application of a photosensitive material such as aminolevulinic acid (ALA) to the skin then exposing it to a laser or special light source. Photodynamic therapy is theorized to work by inhibiting C. acnes and damaging sebaceous glands to reduce sebum production.

Superficial chemical peels may speed up comedo resolution in people with non-inflamed comedonal acne. Glycolic acid and salicylic acid are the most commonly used peeling agents.

Microdermabrasion is a noninvasive procedure that uses tiny needles to exfoliate the skin. 

Comedo extraction is the mechanical removal of comedones through a small incision under local anesthesia.  

DIY at-home treatments 

Although at-home remedies may have some benefit in acne, there is not enough evidence to support their use instead of regular acne treatments.

In one study, topical tea tree oil was shown to be effective at improving mild-to-moderate acne. Another study compared topical tea tree oil to benzoyl peroxide showed improvements with both treatments but tea tree oil was slower to produce effects.

People with mild-to-moderate acne may also benefit from applying green tea lotion to their skin. One study showed a 58% reduction in the number of lesions after six weeks of twice-daily use of green tea lotion.

Tips to Manage Acne

In addition to using acne treatments with proven effectiveness like retinoids and antibiotics, making some lifestyle changes can play a role in improving your acne.

Proper skin care, dietary changes, and stress reduction are all important factors that can help speed up recovery and control breakouts.

Proper skin care

Skin care in people with acne is geared towards avoiding irritation. Following these tips can help you maintain your skin health and hygiene without damaging it:

• Use a synthetic detergent cleanser (syndet) like Cetaphil instead of regular soap. Syndet cleansers have a pH of 5.5 to 7 which is closer to normal skin pH than regular soap.
• Avoid aggressive skin scrubbing and picking your acne pimples. Mechanical damage from aggressive handling of the lesions can promote inflammation and increase scarring.
• Use oil-free, water-based cosmetics instead of oil-based products as they are non-comedogenic.
• Wash your face regularly with warm–not hot–water, particularly after sweating.
• Avoid excessive sun exposure and tanning beds as they can damage your skin and increase inflammation. Some acne medications can make your skin more susceptible to sunburn.

Diet modification

Several studies suggest that high glycemic load diets and high milk consumption may contribute to acne. 

Although more research is needed to define the relationship between acne and diet, many experts recommend switching to a healthier low glycemic load diet, and some recommend cutting down on milk and dairy intake.

Stress reduction

Psychological stress has been linked to increased acne severity. Taking measures to reduce stress such as meditation and regular exercise may improve your acne.

A Word About Acne Scarring

Scarring happens due to aberrant wound healing that is more likely to complicate inflammatory acne lesions. Acne scars can be atrophic (loss of tissue that appears as indentations) or hypertrophic (excess collagen resulting in elevated scars). About 1% of people with acne experience scarring. 

Treatment options for acne scars include laser resurfacing, chemical peels, dermabrasion, injectable soft tissue fillers, steroid injections, cryotherapy (freezing), and surgical excision.

Takeaway

Acne is a common skin condition that causes numerous lesions to appear on the face, neck, and upper body. It is caused by a combination of follicle plugging with oil, bacterial overgrowth, and inflammation, and worsened by factors like stress, smoking, and diet. 

Most people can completely recover from acne with treatment. Treatment options include prescription and over-the-counter medications, antibiotics, and professional treatments like laser resurfacing and chemical peels. Lifestyle modifications can help lessen the severity of acne.