What You Need To Know About Acne

What is acne?

Acne is a common skin condition (also known as zits, pimples, or blemishes) that affects almost everyone at some point.

This inflammatory condition occurs when dried sebum, skin cells, and bacteria (C. acnes) fill and block dilated hair follicles, forming a structure called a comedone.

If the comedone is open, it appears dark and is called a blackhead. Whiteheads are formed when the comedone is closed. Sometimes, comedones become inflamed and appear red and pus-filled.

Anybody — at any age — can develop acne, although it is most common in adolescents and adults.

Main types of acne

The common form of acne (acne vulgaris) can be split into three categories of severity — mild, moderate, and severe.

Acne fulminans and acne conglobata are rare, very severe, and painful forms of acne that leave significant scarring.


How common is acne in the US?

Acne vulgaris is extremely common. The word Vulgaris is Latin for “common.” Acne affects up to 90% of teens and young adults¹. 75–98% of teenagers aged 16–18 years old¹ experience acne. 10–20% of teenagers experience² moderate-to-severe acne.

Adult acne — acne in people over the age of 25 — affects 18% of females and 8% of males³.

Acne can have a negative effect on self-image and mental health. Almost 25%² of teenagers that suffer from acne have suicidal thoughts. These thoughts are twice as common in girls with severe acne than girls with no acne. 

Around 20%⁴ of newborns have neonatal acne. It is usually not a concern and goes away on its own.

Who is most likely to get acne?

The demographics most likely to be affected by acne are:


Teenagers⁵ are the most likely to experience acne, although young adults are also likely to experience acne.


Young males are more likely to experience severe forms⁶ of acne. For teens over 15 years old, acne is more common in boys⁷. Acne is also more common in girls than boys⁸ before age 12. Females are more likely to experience adult acne.


People of all races are affected by acne, but clinical research suggests that moderate-to-severe acne is most common among black women⁹.


Physical symptoms

Acne symptoms can be of varying severity. The following table can help you recognize the symptoms¹ of mild, moderate, and severe forms of acne. Symptoms may be present on the face, chest, upper back, and upper arms as the skin in these areas contain lots of sebaceous glands which make sebum.

Psychological symptoms

Addressing the psychological symptoms of acne is just as important as treating physical symptoms. The psychological symptoms may include:

  • Low mood 

  • Poor self-confidence 

  • Emotional stress 

  • Anxiety 

  • Depression

  • Suicidal thoughts²

If you are struggling with acne and find that it affects how you feel about yourself, or you start experiencing symptoms of anxiety or depression, you must tell your doctor or someone you trust.

Early signs

An early sign of acne is the formation of comedones. For some, these comedones are all they experience. However, comedone formation is the beginning of more severe acne in others.

If your biological parents³ had acne, you are more likely to develop it yourself. As a result, your acne may develop earlier in life and be more severe. If acne runs in your family and you start to develop whiteheads, blackheads, or pimples, discuss appropriate measures with your doctor to keep your acne from worsening.

If you have naturally oily skin or hair, you also may have a heightened risk of developing acne because the oil (sebum) can block pores and hair follicles, forming pimples.

Acne complications

Acne alone is not life-threatening. It does not lead to other physical conditions. However, untreated acne can lead to scarring. These scars are usually permanent and require treatment by a dermatologist to improve them.

Acne can lead to severe psychological conditions such as anxiety and depression. If you experience suicidal thoughts, low self-esteem, or any other psychological symptoms of acne, it’s important to tell someone you trust, such as your doctor.

Likewise, if someone you care about is struggling with acne, keep an eye out for signs of these symptoms and offer emotional support.

  1. Acne | MSD Manual Consumer Version

  2. Acne: Signs and symptoms | American Academy of Dermatology Association

  3. Heredity: A prognostic factor for acne (2006)


There are four main factors in the development of acne.

Blocked hair follicles

Keratinocytes are the predominant cells that make up the outermost layer of your skin. Excess keratinocytes and other substances on the skin can block hair follicles resulting in whiteheads and blackheads.

Excess sebum production

Sebum is the oily substance your body makes to prevent your skin from drying out. If you have oily skin, your body makes more sebum than those with relatively dry skin.

Increased amounts of sebum production correlate with the severity of acne¹.

Suppose you have naturally oily skin or take medication that increases oil production. In that case, you will have a greater chance of developing acne as there is more sebum on your skin to (potentially) block hair follicles.


Cutibacterium acnes (C. acnes) is a bacteria naturally found in large amounts on human skin and hair follicles. It is an opportunistic pathogen. That means it usually is present on healthy skin. However, if your resistance to the bacteria gets lowered or conditions become optimal for bacterial growth, C. acnes can rapidly multiply and cause infection. This infection presents as pus-filled pimples.

C. acnes uses sebum and cellular debris for energy. So anytime your body’s sebum or keratinocyte production increases, C. acnes suddenly have more “fuel” to reproduce, which leads to pimples.


Inflammation is the body’s response to foreign particles, like bacteria. When your body senses something foreign, it sends an army of immune cells — white blood cells — to take care of the invader (C. acnes). These cells attack the bacteria, but they can also damage your cells and tissues in the process.

Although unpleasant, the redness, swelling, and pain felt around pimples are a sign of inflammation, which means your body is trying to fight the infection. The pus you see in a pimple is a mix of dead skin cells and white blood cells, as well as bacteria.

Risk factors

Many factors increase your chances of developing or experiencing more severe acne.


If your biological parents experienced acne, you have an increased risk of developing acne. You may also have an increased risk of it being more severe.


During puberty², your body goes through a lot of changes. In particular, it increases its production of androgens — male sex hormones. Androgens stimulate the sebaceous glands to produce more sebum, which results in oilier skin, increasing the risk of acne.

Hormonal changes

Hormonal changes in young women — such as pregnancy or during the menstrual cycle can increase the risk of acne onset. If you notice a pattern of worsening acne around the time of your period, tell your doctor.


Young males³ tend to be more heavily affected by severe acne than young females. However, both males and females experience severe acne.


Stress increases your body’s production of androgens, increasing the risk of acne in a similar way to puberty.


Smoking⁴ can affect your body’s ability to produce keratin, the protein found in keratinocytes, increasing the risk of follicles becoming blocked and creating inflammation.


Hormone-altering medications, like oral contraceptives (birth control pills), can sometimes cause or worsen acne. If you notice that you develop acne or it worsens after starting a new medication, you must tell your doctor. However, do not stop taking the medication until your doctor advises you.


Many cosmetics, primarily oil-based products, can block hair follicles and clog pores. Cosmetics can also irritate your skin and any already present lesions, worsening your acne.


A general practitioner (GP) or dermatologist can assess acne, and a diagnosis can usually happen by physical examination alone. Your doctor will examine your skin to rule out any other conditions. Rosacea is a condition that can appear similar to acne. However, Rosacea does not have comedones and has a characteristic redness on the nose, forehead, chin, or cheeks.

Other conditions similar to acne include dermatitis, folliculitis, sebaceous hyperplasia, and drug-induced acne-like symptoms. In the process of making a diagnosis, your doctor will also determine the severity of your acne and prescribe appropriate treatment.


It usually takes a few months to see changes in acne symptoms. Therefore, following your doctor’s exact instructions is essential for optimal results. Otherwise, it may take even longer for your acne to clear up. Some treatments are available over-the-counter, but many require a prescription.

The severity¹ of your acne will determine the treatment your doctor prescribes. The following table outlines the different acne treatments by the level of severity.

Topical Retinoids

Topical retinoids reduce the formation of new comedones and reduce sebum production. They are useful for the maintenance of mild acne or in combination with other therapies for moderate acne.

In addition, retinoids may help repair minor scarring and hyperpigmentation left by resolved acne lesions. When combined with topical antimicrobials, they are often the most effective.

Topical retinoids are not suitable during pregnancy².

The most common topical retinoids include:

  • Tretinoin: For prevention of blocking follicles and reducing inflammation.

  • Adapalene: To reduce inflammation and prevent the formation of comedones. 0.1% gel is the only topical retinoid approved by the FDA for over-the-counter use.

  • Tazarotene: Reduces keratinocyte proliferation. It’s often used as an intervention after tretinoin or adapalene does not clear the acne (because it can cause skin irritation).

Side effects of topical retinoids include:

  • Temporarily worsened acne

  • Sensitivity to the sun (photosensitivity)

  • Skin irritation 

  • Dry skin

Benzoyl peroxide

Benzoyl peroxide comes in many forms, such as cream, gel, foam, lotion, or washes. Many of these products are available over-the-counter. BP has antibacterial properties and prevents comedone formation.

You can use it in combination with topical retinoids, but they must be applied separately.

Take care not to bring benzoyl peroxide in direct contact with your favorite clothing or bedding, as it can cause bleaching.

Side effects of benzoyl peroxide products include:

  • Dry and peeling skin 

  • Skin irritation 

  • Dermatitis

Azelaic acid

Azelaic acid is available over-the-counter for mild acne, as either a gel or cream. It stops acne bacteria from reproducing. Azelaic acid also has anti-inflammatory properties and can be used alongside benzoyl peroxide and some other topical treatments.

Side effects include:

  • Skin irritation 

  • Hypopigmentation (lightening) of skin

Topical antibiotics

A prescription is required for topical antibiotics. When used alone, topical antibiotics are often the best for treating inflammatory acne. They target C. acnes and should be used alongside another topical treatment that inhibits the formation of comedones.

Commonly prescribed topical antibiotics include:

  • Erythromycin: Available in foams or gels. Erythromycin reduces the amount of C. acnes on the skin and in hair follicles. 

  • Clindamycin: Targets protein synthesis in bacteria, preventing it from replicating. It can be used as either a gel or a lotion. Unfortunately, some strains of C. acnes are resistant to clindamycin.

Due to increasing antibiotic resistance, it is recommended to use topical antibiotics for short periods and in combination with other topical treatments such as retinoids or benzoyl peroxide.

Side effects of topical antibiotics include:

  • Skin irritation

  • Dryness

  • Dermatitis

Oral antibiotics

Oral antibiotics require a prescription and are ideal for the treatment of moderate, inflammatory acne. They stop the growth of C. acnes, preventing the worsening of acne. To reduce the risk of antibiotic resistance, oral antibiotics should be paired with topical treatments (non-antibiotics) and be used for short periods.

Oral antibiotics prescribed for acne include:

  • Tetracyclines (doxycycline, minocycline) are usually the first choice.

  • Erythromycin 

  • Trimethoprim/Sulfamethoxazole

Side effects of oral antibiotics:

  • Stomach irritation  

  • Sensitivity to the sun (photosensitivity)

  • Allergic reaction

  • Rash

  • Thrush (yeast infection)

Oral hormonal therapy

Oral hormonal therapy is prescribed as an acne treatment for women. Two common hormonal therapies are spironolactone and the oral contraceptive pill. Unfortunately, neither of these treatments can be taken while pregnant.

Spironolactone suppresses the production of androgens by the ovaries, thereby reducing sebum production, but it is not FDA-approved³ for the treatment of acne.

If you have a kidney disease, spironolactone may cause complications by affecting potassium levels. It is best to discuss this with your doctor.

Side effects of spironolactone are:

  • Dizziness

  • Irregular periods

  • Tender breasts 

  • High blood potassium levels

In women, the oral contraceptive pill can reduce sebum production and be used alongside other acne treatments, including spironolactone.

For the oral contraceptive pill to be an effective acne treatment, it should be used for at least a year (as it usually takes at least 3-6 months to see improvements). Certain conditions such as deep vein thrombosis, being a smoker, or suffering from migraines, may make birth control pills unsuitable.

Common side effects of oral contraceptives include:

  • Irregular periods

  • Nausea

  • Sore or tender breasts

  • Bloating 

  • Mood changes

  • Headaches 

  • Hypertension

The oral contraceptive pill should only be prescribed as an acne treatment if you do not want to conceive. Starting the oral contraceptive pill requires an in-depth discussion with your doctor.

Oral isotretinoin

Isotretinoin is for severe acne, which has not responded to other treatments. It is effective in targeting all four causes of acne. Treatment usually lasts 16-24 weeks but may last longer.

Isotretinoin is teratogenic, which means it causes fetal abnormalities and miscarriages. Therefore, women taking isotretinoin should use two types of contraception and take a monthly pregnancy test if they are sexually active.

Other significant side effects include mood changes or depression, liver dysfunction, and inflammatory bowel disease.

It is important to use moisturizer, lip balm, and sunscreen daily when taking isotretinoin, as it dries out your skin and makes you more susceptible to sun damage.

Isotretinoin is often well-tolerated. However, those who take it must enter an FDA-approved risk management program. Being monitored by a dermatologist is also required.

Side effects of isotretinoin include:

  • Dry skin and mouth 

  • Nosebleeds

  • Sensitivity to the sun (photosensitivity)

  • Mood changes 

  • Joint pain 

  • Miscarriage

  • Fetal abnormalities


Severe acne often requires removal. There are many methods, including:

  • Comedone extraction

  • Cryolush therapy, using solid carbon and acetone 

  • Cryotherapy, using very cold liquid nitrogen to freeze tissue

  • Intralesional corticosteroid injection. Triamcinolone acetonide is injected into the cyst to reduce its size

Scar treatment

Moderate/severe acne can leave scars. To help improve the appearance of these scars,  you can consider one of the following treatments:

  • Regular use of sunscreen

  • Azelaic acid and hydroquinone creams

  • Silicone dressings

  • Laser resurfacing

  • Chemical peels 

  • Microneedling 

  • Dermabrasion 

  • Steroid injections

  • Punch excisions 

  • Subcision (used for sunken acne scars to separate the scar tissue for the underlying skin)

Lifestyle changes

There are several lifestyle changes you can make to manage and prevent the worsening of acne:

Mild cleansers

Use a mild, water-based cleanser to avoid further irritating your skin. If you are prone to oily skin, use a product with salicylic acid or benzoyl peroxide.


Use a moisturizer to prevent peeling from drying acne treatments.

Oil-free products

Use oil-free makeup and sunblock. Try to find products with ‘non-comedogenic’ on the label. These are less likely to clog your pores than other products. Remove all cosmetics before bed and clean your make-up brushes and applicators frequently.


While there is no consistent evidence that dietary choices cause acne, some people notice flare-ups correlated with certain foods, particularly milk⁴ or sugar, which are known to have an inflammatory⁵ effect on the body. If you notice a connection between what you eat and acne flare-ups, let your doctor know.

Don’t pick

Although tempting, don’t pick at your acne. It will only make it worse and more likely to scar.

Can acne be cured?

There is no cure for acne. However, symptoms are treatable, and new breakouts are often preventable. Most people find that their acne improves with age.


There is no absolute way to prevent acne. Even so, looking after your skin using the skincare tips above and working with your doctor will optimize your skin’s condition and lower the risk of developing severe acne.

Doctors & specialists

A family doctor is typically the first point of contact if you are concerned about acne. If you have been with your doctor for a while, they will know your physical and psychological history, making it easier to assess suitable treatment. You might be referred to a dermatologist if your acne is considered severe. However, general practitioners and dermatologists are the primary doctors who treat acne.

Counselors and psychologists also treat the psychological effects of acne.