Globally, acne affects approximately 650 million people, or about 9.4% of the population, as of 2010.[158] It affects nearly 90% of people in Western societies during their teenage years, but can occur before adolescence and may persist into adulthood.[19][20][23] While acne that first develops between the ages of 21 and 25 is uncommon, it affects 54% of women and 40% of men older than 25 years of age,[47][159] and has a lifetime prevalence of 85%.[47] About 20% of those affected have moderate or severe cases.[2] It is slightly more common in females than males (9.8% versus 9.0%).[158] In those over 40 years old, 1% of males and 5% of females still have problems.[20]
Whereas blackheads are open, whiteheads are closed comedones. They appear as small, white, round bumps on the skin’s surface. Whiteheads form when a clogged pore is trapped by a thin layer of skin leading to a buildup of pus. They range in size – from virtually invisible to large, noticeable blemishes – and can appear on the face or all over the body. Whiteheads are generally painless and non-inflammatory, so they don’t exhibit redness or swelling. Although they are unsightly, this type of pimple is generally considered a mild form acne.

Flutamide, a pure antagonist of the androgen receptor, is effective in the treatment of acne in women.[101][108] It has generally been found to reduce symptoms of acne by 80 or 90% even at low doses, with several studies showing complete acne clearance.[101][109][110] In one study, flutamide decreased acne scores by 80% within 3 months, whereas spironolactone decreased symptoms by only 40% in the same time period.[110][111][112] In a large long-term study, 97% of women reported satisfaction with the control of their acne with flutamide.[113] Although effective, flutamide has a risk of serious liver toxicity, and cases of death in women taking even low doses of the medication to treat androgen-dependent skin and hair conditions have occurred.[114] As such, the use of flutamide for acne has become increasingly limited,[113][115][116] and it has been argued that continued use of flutamide for such purposes is unethical.[114] Bicalutamide, a pure androgen receptor antagonist with the same mechanism as flutamide and with comparable or superior antiandrogenic efficacy but without its risk of liver toxicity, is a potential alternative to flutamide in the treatment of androgen-dependent skin and hair conditions in women.[106][117][118][119]
The severity of acne vulgaris (Gr. ἀκµή, "point" + L. vulgaris, "common")[24] can be classified as mild, moderate, or severe as this helps to determine an appropriate treatment regimen.[20] There is no universally accepted scale for grading acne severity.[15] Mild acne is classically defined by the presence of clogged skin follicles (known as comedones) limited to the face with occasional inflammatory lesions.[20] Moderate severity acne is said to occur when a higher number of inflammatory papules and pustules occur on the face compared to mild cases of acne and are found on the trunk of the body.[20] Severe acne is said to occur when nodules (the painful 'bumps' lying under the skin) are the characteristic facial lesions and involvement of the trunk is extensive.[20][25]
Use a toner after cleansing. After you wash your face, exfoliate, or apply a face mask, apply a toner to the entirety of your face. Toners work to tighten pores making it less likely that dirt and oil will become trapped in them. Buy acne toners at a local drugstore, or use witch hazel or apple cider vinegar dabbed on with a cotton ball. Don’t rinse toners after application - allow them to stay on your skin.
Many skin conditions can mimic acne vulgaris, and these are collectively known as acneiform eruptions.[28] Such conditions include angiofibromas, epidermal cysts, flat warts, folliculitis, keratosis pilaris, milia, perioral dermatitis, and rosacea, among others.[20][72] Age is one factor which may help distinguish between these disorders. Skin disorders such as perioral dermatitis and keratosis pilaris can appear similar to acne but tend to occur more frequently in childhood, whereas rosacea tends to occur more frequently in older adults.[20] Facial redness triggered by heat or the consumption of alcohol or spicy food is suggestive of rosacea.[73] The presence of comedones helps health professionals differentiate acne from skin disorders that are similar in appearance.[8] Chloracne, due to exposure to certain chemicals, may look very similar to acne vulgaris.[74]
Light therapy is a treatment method that involves delivering certain specific wavelengths of light to an area of skin affected by acne. Both regular and laser light have been used. When regular light is used immediately following the application of a sensitizing substance to the skin such as aminolevulinic acid or methyl aminolevulinate, the treatment is referred to as photodynamic therapy (PDT).[10][129] PDT has the most supporting evidence of all light therapies.[78] Many different types of nonablative lasers (i.e., lasers that do not vaporize the top layer of the skin but rather induce a physiologic response in the skin from the light) have been used to treat acne, including those that use infrared wavelengths of light. Ablative lasers (such as CO2 and fractional types) have also been used to treat active acne and its scars. When ablative lasers are used, the treatment is often referred to as laser resurfacing because, as mentioned previously, the entire upper layers of the skin are vaporized.[140] Ablative lasers are associated with higher rates of adverse effects compared with nonablative lasers, with examples being postinflammatory hyperpigmentation, persistent facial redness, and persistent pain.[8][141][142] Physiologically, certain wavelengths of light, used with or without accompanying topical chemicals, are thought to kill bacteria and decrease the size and activity of the glands that produce sebum.[129] The evidence for light therapy as a treatment for acne is weak and inconclusive.[8][143] Disadvantages of light therapy can include its cost, the need for multiple visits, time required to complete the procedure(s), and pain associated with some of the treatment modalities.[10] Various light therapies appear to provide a short-term benefit, but data for long-term outcomes, and for outcomes in those with severe acne, are sparse;[144] it may have a role for individuals whose acne has been resistant to topical medications.[10] A 2016 meta-analysis was unable to conclude whether light therapies were more beneficial than placebo or no treatment, nor how long potential benefits lasted.[145] Typical side effects include skin peeling, temporary reddening of the skin, swelling, and postinflammatory hyperpigmentation.[10]
Our favorite for banishing blemishes on the fly, Glossier's zit stick is not only effective, but it's portable. Just stash it in your purse for any unexpected breakouts! Packed with acne-fighting benzoyl peroxide, this convenient roll-on works extremely quickly. In a clinical trial, 83% of test subjects said that it lessened the appearance of pimples in just 3 hours. We've tried it ourselves and can confirm the 3-hour claim is true.
How to Handle It: Pair two of the best-known acne-fighting ingredients, salicylic acid and benzoyl peroxide, in the week leading up to your period. (If you're feeling bloated, now's the time to do it.) The combo can help prevent hormonal acne from happening in the first place. Zeichner suggests following a salicylic acid wash, like fan-favorite Neutrogena Oil-Free Acne Wash Pink Grapefruit Facial Cleanser ($7), with a benzoyl peroxide spot treatment, such as Murad Acne Spot Fast Fix ($22). If you're still seeing zits, "visit your dermatologist to discuss prescription options, like birth control pills, oral spironolactone — which blocks oil — or topical Aczone 7.5 percent gel," says Zeichner. "It's shown to be particularly effective in adult women without causing irritation." Oral contraceptives level out those hormone fluctuations, keeping your oil production normal and your skin clear.
If you have acne that's not responding to self-care and over-the-counter treatments, make an appointment with your doctor. Early, effective treatment of acne reduces the risk of scarring and of lasting damage to your self-esteem. After an initial examination, your doctor may refer you to a specialist in the diagnosis and treatment of skin conditions (dermatologist).
Dermatologists aren’t sure why azelaic acid is so effective at clearing up inflammation, but it’s often used as an option for sensitive skin or pregnant patients. Linkner says the ingredient is good at treating malasma, acne, and rosacea. Your dermatologist can prescribe a foam product with azelaic acid, and you can also find beauty products with very small amounts of this active ingredient.
The recognition and characterization of acne progressed in 1776 when Josef Plenck (an Austrian physician) published a book that proposed the novel concept of classifying skin diseases by their elementary (initial) lesions.[164] In 1808 the English dermatologist Robert Willan refined Plenck's work by providing the first detailed descriptions of several skin disorders using a morphologic terminology that remains in use today.[164] Thomas Bateman continued and expanded on Robert Willan's work as his student and provided the first descriptions and illustrations of acne accepted as accurate by modern dermatologists.[164] Erasmus Wilson, in 1842, was the first to make the distinction between acne vulgaris and rosacea.[165] The first professional medical monograph dedicated entirely to acne was written by Lucius Duncan Bulkley and published in New York in 1885.[166][167]
A study conducted by the Department of Dermatology at the University of Freiburg in Germany reports that using frankincense and five other plant extracts for antimicrobial effects on bacteria and yeast relating to the skin proved effective. The study concluded that their antimicrobial effects were powerful enough to be used as a topical treatment of some skin disorders, including acne and eczema. (19) 
What is a pimple in the first place? A pimple is a small comedone, pustule or papule that forms a skin lesion; the more technical term is acne vulgaris. There are numerous causes, but regardless of the cause, pimples develop when the sebaceous glands (oil glands) get clogged and infected from bacteria. This is why pimples swell up and become red, pus-filled lesions on the surface, and just under the surface, of the skin. (2)

Everything you need to know about blackheads Blackheads are small lesions that often appear on the face or neck. They are a feature of mild acne, and handling blackheads in the right way can help to prevent the acne from becoming more severe. We look at ways to reduce and treat breakouts. Learn more about what causes blackheads and how to get rid of them here. Read now
When we sleep, healing happens, and at the same time, it’s a great time to apply a home remedy and let it get it to work on eliminating toxins that can cause acne. The Psychiatric Clinics of North America reports that stress is a factor affecting all organs. Though it’s easy to forget, the skin is an organ. In fact, it’s your largest organ! Getting plenty of rest can help reduce acne-associated stress. (9) 
Acne appears when a pore in our skin clogs. This clog begins with dead skin cells. Normally, dead skin cells rise to surface of the pore, and the body sheds the cells. When the body starts to make lots of sebum (see-bum), oil that keeps our skin from drying out, the dead skin cells can stick together inside the pore. Instead of rising to the surface, the cells become trapped inside the pore.