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

• Acne develops when skin follicles become blocked with oil and debris, and sometimes compounded by bacteria and inflammation
• Noninflammatory acne results in blackheads and whiteheads
• Inflammatory acne is more severe, resulting in inflamed nodules and cysts which can cause scarring
• With proper treatment, most people can overcome or control their acne
• Lifestyle modifications can help improve this condition

Acne is the most common skin disorder in the United States, affecting up to 95% of adolescents at some point. The psychological and social impact of acne can be severe and are hard to quantify. While mild cases of noninflammatory acne often resolve on their own, without treatment, severe acne can cause significant and long-lasting skin damage.

What Is Acne? 

Acne vulgaris is a skin disorder that results when oil, dead skin cells and other debris accumulate in the hair follicle. Inflammation and the overgrowth of Cutibacterium acnes (formerly Propionibacterium acnes) bacteria also play 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; severe acne is characterized by inflamed cysts and nodules.

Diagnosis

While the diagnosis of acne is relatively straightforward in most cases, some conditions can mimic acne by producing similar lesions. 

Conditions that can resemble acne:

• Rosacea is a chronic facial skin condition that causes redness and may be accompanied by  papules or pustules; 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 such as steroids and hormonal contraceptives

Types of Acne

The two main types of acne, inflammatory and noninflammatory, represent the spectrum of this  skin disorder. Inflammatory acne is the more severe form.

Noninflammatory acne

Noninflammatory 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 (a protein that binds skin cells together) begin to clog pores, microcomedones (small clogged pores) form. Microcomedones are considered preliminary acne lesions and are typically not visible.

Closed comedones

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

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

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 becomes inflamed. They are raised, tender small bumps that are pink to red in color.

Pustules

Pustules are large, painful pus-filled bumps on the skin. Due to the presence of pus, the pustule’s center is white or yellowish in color, and can be surrounded by swelling and redness. 

Pimples

Pimples are not a separate type of acne lesion. A pimple is a generic term for a small inflammatory lesion; 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 fluctuations, bacterial colonization and inflammation.

Sebum is an oily material secreted from sebaceous glands located around the hair follicles. Excessive sebum accumulation provides a nutrient-rich environment for the colonization and proliferation of C. acnes. 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 which clog pores 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 make one predisposed to acne.

Risk Factors

Several risk factors can contribute to the development and severity of acne. While these factors cannot cause acne on their own, they can worsen this condition.

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 worsening acne. Although many people believe chocolate contributes to the development of acne, a clear link has not been established.

Genetics

Studies demonstrate that people with first-degree family members who had acne have more than a three-fold higher risk of developing it than those who don’t. This suggests that inheritance plays a strong role in the development of acne.

Smoking

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

Stress

Emotional stress can contribute to increasing the severity of acne. Stress increases the presence of hormones which stimulate the sebaceous glands, causing an increase in oil production.

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 and managed by using one or more of the available acne treatments.  

Acne Treatments

Treatment options for acne include topical treatments, oral medications and professional treatments. Several medications are typically used simultaneously to optimize results.

Over-the-counter topicals

Topical acne treatments include benzoyl peroxide, salicylic acid, alpha-hydroxy acids and sulfur.

Sulfur is believed to work by removing dead skin cells and inhibiting the replication of C. acnes bacteria. 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 such as benzoyl peroxide and sulfacetamide.

Alpha-hydroxy acids such as glycolic acid can eliminate excess sebum, reduce the level of bacteria and soothe inflammation. Both glycolic and lactic acid can improve acne by reducing dead skin cell shedding and fighting skin color changes that may occur due to inflammation.

Benzoyl peroxide is a first-line treatment and preventative in acne therapy as it kills acne-causing bacteria, clears skin of excess oil and helps strip away dead skin cells.

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

Prescription topicals

Prescription topical acne medications include retinoids, antibiotics and azelaic acid.

Retinoids such as isotretinoin are derivatives of vitamin A, and can effectively reduce skin cell shedding, unclog pores, prevent microcomedone formation and counteract inflammation. 

Commonly prescribed retinoids include tretinoin (0.02–0.08%), tazarotene (0.05–0.1%) and adapalene 0.3%. Adapalene 0.1% gel (Differin) is available without a prescription. 

Azelaic acid has comedolytic, antimicrobial and anti-inflammatory properties. Azelaic acid is FDA-approved for the treatment of acne and available in 15% and 20% concentrations.

Oral isotretinoin

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

Length of treatment and dosage will depend on a number of factors and will be determined by the provider’s judgment. This medication is used with caution as it is associated with a number of adverse physical and psychological side effects.

Depending on the dose and severity of acne treatment, isotretinoin can clear acne in 4–6 months. The recommended dose ranges from 0.5 to 1.0 mg/kg per day divided into two doses for 15–20 weeks.

Low-dose isotretinoin is another viable option. In one three-month study, participants with moderate-to-severe acne had very good results with 0.3 to 0.4 mg/kg per day, with a low incidence of serious side effects.

Antibiotics

Antibiotics are integral components of acne treatment regimens. Antibiotics work against acne-causing bacteria, and some have anti-inflammatory properties. Both topical and oral antibiotics are effective in treating acne.

Antibiotics are applied directly to acne lesions or taken by mouth once or twice daily. They are typically prescribed for 3–4 months initially, after which the drug regimen is reevaluated.

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

Professional treatments 

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

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. 

A study review found this treatment effectively treated acne and was an appropriate add-on therapy for mild-to-severe acne. This therapy is theorized to work by inhibiting C. acnes and damaging sebaceous glands to reduce sebum production, however one small clinical trial suggests there is an alternate mode of action at work, and further research is necessary.

Light chemical peels can speed up comedo resolution in people with noninflamed comedonal acne. Glycolic and salicylic acid are the most commonly used peeling agents.

Microdermabrasion is a noninvasive procedure that uses tiny needles to exfoliate the skin by removing the outermost layer. Ideal for mild acne, it unclogs pores of oil, dirt and debris.

Comedo extraction is the mechanical removal of blackheads through gentle pressure at the opening of the pore or by incision under local anesthesia for closed comedones.  

DIY at-home treatments 

While at-home remedies can provide some relief from acne symptoms and support traditional therapies, they typically cannot provide the same results as over-the-counter (OTC) or prescribed treatments alone. 

In one study, topical application of tea tree oil produced significant results and was well tolerated. 

Those with mild-to-moderate acne may 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..

Tips to Manage Acne

In addition to using acne treatments with proven effectiveness such as retinoids and antibiotics, making some lifestyle changes can go a long way in improving your acne.

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

Proper skin care

Skin care in people with acne is geared toward avoiding irritation. Following these tips can help you maintain your skin health and hygiene, and avoid damaging it:

• Use a synthetic detergent cleanser (syndet) such as Cetaphil rather than regular soap; syndet cleansers have a pH of 5.5 to 7.0 which is closer to normal skin pH than regular soap
• Avoid aggressive skin scrubbing and picking at pimples; mechanical damage from aggressive handling of lesions can promote inflammation and increase scarring
• Use water-based products instead of oil-based, as they are noncomedogenic
• Wash your face regularly with warm, not hot, water; hot water can strip skin of its natural oils and trigger an overproduction of oil as compensation
• Avoid excessive sun exposure and tanning beds as they can damage 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 dairy 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 reducing dairy consumption for improved general health.

Stress reduction

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

A Word About Acne Scarring

Scarring is unfortunately a common occurrence with acne, especially with severe acne. These 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 very common skin condition that causes numerous lesions to appear on the face, neck, and upper body. It is caused by a combination of follicles becoming clogged with oil, bacterial overgrowth and inflammation. It is worsened by factors such as stress, smoking and diet. 

Most people can completely recover from acne breakouts with the right treatment or combination of treatments. Options include topical OTC products and oral and topical prescription medications. 

Antibiotics are an important component of acne therapy as are professional treatments such as laser resurfacing and chemical peels. Lifestyle modifications can help lessen the severity of acne.

Finding the solution that works for you may take some trial and error but with time and consistent treatment, will produce positive results.