Acne, also known as pimple or blackhead, is a very common skin disease that occurs due to obstruction of the pilosebaceous follicles. This obstruction can be caused by the excess of sebum produced by sebaceous glands and also by the presence of dead cells. The accumulation causes inflammation of the skin and this environment can promote the appearance and growth of bacteria, especially Propioniumbacterium acnes. The acne lesions heal slowly.

Sebum, an oily product, has the main function of lubricating hair, hair and skin. Excessive sebum production and the accumulation of dead cells in the hair follicles can obstruct the follicles. The formation of these blocks favors the swelling of the follicle walls, which can acquire a white color. They can also open and acquire a black color, they are the blackheads. In case of inflammation, the follicles can also become red.

Acne forms
According to its severity, acne can be classified into:

– Acne grade I: presence of open or closed comedones with few signs of inflammation.

– Grade II acne: presence of open and / or closed comedones inflamed with pus (superficial papular-pustular acne).

– Acne grade III: presence of open and / or closed comedones with pus and inflammatory nodules (deep papular-pustular acne).

– Acne grade IV: presence of nodules and cysts and also called acne conglobata.

See the figure below for acne levels:


beautiful skin Acne appears most commonly among young people and adolescents, beginning at puberty. Research shows that acne affects 70-95% of teenagers aged 13 to 18 years, 8% of young people between 25-34 years old and 3% of adults between 35-44 years old. According to the Ministry of Health, 20% of people between 15 and 25 years do not have the disease. About 40% of young people have severe acne, requiring medical treatment.

Although acne is more frequent during adolescence, more and more adults after the age of 30 have pimples due to several factors, both genetic and environmental (see causes ). Data indicate that acne is more likely to develop in men, however, in women it seems to be more resistant. At 40 years old, there are injuries in 1% of men and 5% of women.

It is estimated that, in general, acne disappears spontaneously at 20 years of age.


Acne occurs when the pilosebaceous follicles are blocked by the excess sebum produced and the presence of dead skin cells. Once blocked, the follicles can remain closed, forming the pimples, or open, forming blackheads with black dots in the center. The inflamed follicles become red and prominent, usually with pus (white dots) in the center. See below how acne forms:

– Juvenile acne is caused by hormonal imbalances: at puberty, sebum secretion, which depends on androgens (male sex hormones, in particular testosterone) and estrogens (female sex hormones) significantly increases and influences the condition of the skin. It is not yet known exactly what factors cause the increased production of sebum in the skin. Some of the causes that seem to be related, depending on the type of acne, are:

– It is also important to know that acne (juvenile or not) has a strong hereditary incidence (influence of genes). For example, if the parents had acne, the child is 60% more likely to have acne.

 In other types of acne, and sometimes even in juvenile acne, several causes can originate it. We emphasize the importance of a bacterium: Propioniumbacterium acnes or stress, which can also favor acne, due to an increase in sebum production.

Washing the skin with soaps or exfoliating chemicals can irritate the skin and increase sebum production, making acne worse. A simple and gentle wash is more suitable than abrasive products.

– Food (chocolate …) can favor the appearance of acne.

Studies have shown that in adults, particularly, consumption of milk and dairy products such as cheese and butter can aggravate acne.

In addition, sugar-rich cereals and bread (especially white), French fries and chocolate also have a negative effect on acne. It is estimated that chocolate favors the appearance of acne, it is precisely because of its high concentration of sugar. Sometimes this increases the level of insulin, which can favor the onset of acne.

– Ingestion of certain medications, such as corticosteroids, hormones (androgens), lithium or vitamin B12 .

It is possible that an excess of vitamin B12 promotes acne. A June 2015 study by the University of California Los Angeles (UCLA) in the United States linked vitamin B12 to the onset of acne. The study was published in the June 24, 2015 issue of the scientific journal Science Translational Medicine, coordinated by dermatologist Dr. Noah Craft.
According to the results of the study, vitamin B12 causes bacteria normally found on the skin to start producing chemical agents that cause the appearance of acne. The bacterium in question, found in both people with and without acne, is Propionibacterium acnes. The difference is that in people with acne, this bacterium has a different metabolism. The researchers found 109 genes that are more active in bacteria from people with acne and 27 less active genes.
The researchers gave vitamin B12 supplements to 10 individuals without acne, and one of them developed acne 1 week later. This study provides a possible explanation for a fact that scientists already knew but did not understand why, that vitamin B12 causes acne. Read more

Risk groups

The main risk groups for acne are:

Acne risk groups

– Adolescents and young people entering puberty, due to intense hormonal variations that occur at that time.

– Women before menstruation, also due to fluctuations in the levels of female hormones.

– Men in general, due to genetic factors and hormones like testosterone.

– Pregnant women.

– Patients using cortisone and certain medications.

Some risk factors can also be associated with the disease:

– Use of very oily cosmetics on the skin can clog pores, causing inflammation and acne.

– Use of abrasive products, which can lead to an increase in sebum production by the sebaceous glands.

– Exposure of the skin to products that cause friction, such as helmets, necklaces, phones, etc…

– Excessive skin exposure to the sun can aggravate some acne.


Acne symptoms The most common form is juvenile acne, which affects about 80% of adolescents. It is characterized, in most cases, by open comedones (blackheads with black dots in the center) or closed (small reddish or whitish pimples), present on the skin. You should know that open pores are black because of oxidation on the surface of the sebum lipids.

In case of acne, the skin may become oily, but this is not the rule for all types of acne.

Other forms assumed by acne are:

– Papules: small, red, swollen lesions present in hair follicles. They can be red and soft.

– Pustules: they are red, soft lesions with the presence of pus.

– Nodules: present as large, solid and painful lesions under the surface of the skin. The nodules are formed by the accumulation of secretions at the bottom of the hair follicles. The nodules can affect teenagers with severe acne (grade IV acne), for example in the form of acne called acne conglobata. These nodules can cause scarring.

– Cysts: they are very painful lesions, with nodules below the surface of the skin. Cysts can cause scarring on the skin. They are full of pus.

Body parts affected by acne – Where is acne located?
The pimples are usually located on the face, back, chest, neck, shoulders or neck. These areas have a high concentration of sebaceous glands.


The diagnosis of acne is made by simple physical examination. The doctor may use magnifiers or magnifying glasses to check the extent and depth of the acne. The patient’s history is also important and the doctor may ask if there are resistant cases of acne in the family, exposure to oily or abrasive products, severe exposure to the sun, etc.

Acne diagnosis

In the diagnosis of acne, it is important to check the severity of the lesions and their resistance to medications. The doctor will evaluate the potential of the lesions to form scars and indicate the appropriate treatment to heal them. This is usually done based on the number of acnes present and how severe they are (from I-IV).

Acne is easy to diagnose and is hardly confused with other skin conditions, such as impetigo or boils.


Acne does not normally cause other health complications. However, in the most severe cases, the lesions may leave sequelae such as scarring in the affected regions. These scars are usually difficult to remove and require very severe treatments, such as surgical and laser peels.

Acne complications

Psychologically speaking, acne can cause a reduction in self-esteem, especially in young people and adolescents, who feel less accepted in society. A study published in the Journal of Investigative Dermatology conducted in Oslo found that teenage girls with severe acne are twice as likely to think about committing suicide and boys three times as likely as their friends who don’t suffer from it. In addition to suicidal ideation, these young people, the study revealed, have social relationship problems, not having friends, boyfriends or even performing poorly at school.


Attention: for all acne treatments it is important to be patient, as the results will only appear after a few weeks.

Acne treatment For superficial acne or non-severe acne, a topical treatment is sufficient, as well as good hygiene, to limit acne bacteria (morning and night, wash the areas where acne might be present and use a mild soap for the skin) sensitive). Prescription-free products include cosmetics or drugs that contain sulfur, salicylic acid, lactic acid, resorcinol and benzoyl peroxide.

We can then see that hygiene care is very important, as well as cleaning the skin with a mild soap, twice a day, or products that remove dead cells, to be used once or twice a week (Normaderm® Vichy® gel).

Benzoyl peroxide- based drugs are effective for treating benign to moderate acne vulgaris. This product has a proven anti-acne effect, thanks to a reduction in the formation of comedones and the production of sebum. It also prevents the growth of acne bacteria.

Note: benzoyl peroxide- based medicines contain, as the name implies, a peroxidized derivative, which bleaches hair and especially fabrics (towels, clothes, bed sheets, etc.), so be careful when applying the product in order to avoid these incidents and spending on unnecessary clothes! When buying a benzoyl peroxide-based medicine, read the package insert and ask your doctor for advice.

Salicylic acid is often used topically against acne.

Another product can be used to treat acne: it is motretinide in cream (which will take at least 6 to 8 weeks of treatment to have an effect), a product particularly effective against comedones.

In case of more pronounced acne and when the dermatologist finds it better, he may also prescribe topical antibiotics , such as clindamycin . In this case it is important not to self-medicate and consult a doctor, dermatologist or general practitioner who will be able to prescribe the appropriate medicine.

Other topical products for acne are the retinoid derivatives of vitamin A, such as tretinoin, adapalene and tazoretene. They work because they increase cell turnover and prevent follicle obstruction. Antibiotics other than clindamycin are also indicated, such as erythromycin. The combination of clindamycin and benzoyl peroxide is superior to the use of each product individually.

In severe acne (characterized, for example, by fever and pain, including in the joints close to skin lesions), a medical consultation is highly recommended. The dermatologist may prescribe, for example, antibiotics to be taken orally (not topically), from the family of tetracyclines ( doxycycline , minocycline , …) or topical antibiotics, derived from vitamin A, in ointment or orally ( isotretinoin ).

Caution: Isotretinoin-based drugs can cause severe malformations in pregnant women and dry lips and eyes. This medicine should therefore only be used in case of severe acne or resistance to other treatments.

Isotretinoin is 80% effective if a complete treatment is followed, according to Rutgers Robert Wood Johnson Medical School in the United States, which published a press release in April 2019 .

Other treatments include laser exposure and phototherapy. This type of therapy helps to reduce oil production by the sebaceous glands and also kills the bacteria that cause inflammation. In addition, it helps in the texture of the skin and reduces scarring marks.

For the treatment of scars left by acne, several approaches are indicated such as peeling, dermabrasion or surgical skin sanding, microdermabrasion, laser therapy, plastic surgery of the skin, etc.

Special: women and acne

In some women, taking contraceptives can have a positive effect on acne (leading to a cure). However, the pill can also have the opposite effect, so talk to your doctor for more information and to find the best treatment. Contraceptives based on norgestimate, chlormadinone, among others, have a beneficial effect in improving acne.

Acne treatment

We also emphasize that in some women, acne can be caused by an excessive production of male hormones. Taking an anti-androgen pill, cyproterone acetate, can reduce acne in some women. This class of pills is indicated, above all to treat acne and to combine with a means of contraception.
The oral drug spironolactone, a hypotensive agent, is particularly effective in adult women suffering from acne, as revealed in a study published in February 2019 in the scientific journal Dermatologic Clinics.

Natural treatment

The medicinal plants mentioned below showed efficiency in the treatment of acne. In our opinion they work more as a complementary measure than as a main treatment. As the main therapy, favor classic treatments (medicines).