Acne vulgaris (or simply acne) is a common human skin
disease, characterized by areas of skin with seborrhea (scaly
red skin), comedones
(blackheads and whiteheads), papules (pinheads), nodules (large papules), pimples, and
possibly scarring. Acne affects mostly skin with the densest population of sebaceous
follicles; these areas include the face, the upper part of the chest, and
the
back.[2] Severe acne is inflammatory, but acne can also manifest in noninflammatory forms.[3] The lesions are caused by changes in pilosebaceous units, skin structures consisting of a hair follicle and its associated sebaceous gland, changes that require androgen stimulation.
back.[2] Severe acne is inflammatory, but acne can also manifest in noninflammatory forms.[3] The lesions are caused by changes in pilosebaceous units, skin structures consisting of a hair follicle and its associated sebaceous gland, changes that require androgen stimulation.
Acne occurs most commonly during adolescence,
affecting an estimated 80-90% of teenagers in the Western
world. Lower rates are reported in some rural societies. In adolescence,
acne is usually caused by an increase in androgens such as testosterone,
which occurs during puberty, regardless of sex. For most people,
acne diminishes over time and tends to disappear — or at the very least
decreases — by age 25. There is, however, no way to predict how long it will
take to disappear entirely, and some individuals will carry this condition well
into their thirties, forties, and beyond.[10]
Aside from scarring, its main
effects are psychological, such as reduced self-esteem]
and in very extreme cases, depression or suicide. One
study has estimated the incidence of suicidal ideation in patients with acne as
7.1%. Acne usually appears during adolescence,
when people already tend to be most socially insecure. Early and aggressive
treatment is therefore advocated by some to lessen the overall long-term impact
to individuals.
Types of Acne
White heads
We’ll start with whiteheads because whiteheads were always the ones that confused me. To me, it made perfect sense that whiteheads would be the smallish red pimples with the “white” pussy “heads” on them. But apparently those are actually called pustules (I find the names kinda revolting, you?).
Anyway, whiteheads are simply clogged pores that are not inflamed. They are clogged below the surface of the skin, so they remain closed and flesh coloured, but create a little bump on the skin.
Blackheads
Then comes blackheads. Blackheads are basically the same as whiteheads – a
non-inflamed clogged pore – but the difference is that the top is open and
therefore exposed to the air. The air oxidizes the sebum and keratin that’s
stuck there and it turns black.Note: Many people ask me how to get rid of clogged pores like whiteheads and blackheads… I find that lots of leafy green vegetables works a treat. But sometimes these suckers are stubborn anyway, and that is why I like jojoba oil so much. Jojoba oil is the most molecularly similar thing to our own sebum, so it is the best for going into the pores, dissolving the plug and unclogging your skin. Adding some super finely ground sea salt to your facial routine for mild exfoliation is also a good trick.
Sebaceous Filaments
What are sebaceous filaments?It’s what you think are the blackheads all over your nose and surrounding area. Guess what? Almost everyone thinks they have a blackhead problem all over these areas when in reality, every single human has these and they aren’t clogged pores at all! They are actually just the oil glands in your skin.. the tiny tubes that supply a pore with sebum. The tips of them are what you see dotted around your nose and they often resemble tiny blackheads, although they’re usually lighter in colour, evenly spaced, and smooth to the touch, unlike blackheads.
They are meant to be there, everyone has them, and you can’t make them go away. If you try, they fill right back up.
I just wanted to bring this to light because many people are needlessly stressing out about their perfectly normal, healthy sebaceous filaments when they shouldn’t be!
Papules
And now we get into inflamed acne. Inflamed acne is when a clogged pore – a whitehead or a blackhead – gets irritated and becomes inflamed. This mean it swells, turns red, and begins to hurt. (This is why we want to avoid irritating cleansers + your fingers so that a clogged pore doesn’t get inflamed!)Papules are tender red bumps … usually fairly small, up to a cm in diameter, and somewhat raised. The defining factor is that they are not filled with pus, although they may go on to fill with pus later on and become a pustule.
Absolutely do not squeeze these!!! It’s only going to make matters worse and encourage scarring.
Pustules
Pustules are your classic zit. Hard, inflamed, and full of pus that has the defining white or yellow centre. May remind you of a volcano. While it’s ever tempting to pop these, please try to refrain. It may not be as harmful to pop one of these vs squeezing some other varieties, especially if it’s waiting to burst… but I still would really not recommend it (from a former chronic popper – trust me).Nodules and Cysts
Nodules are generally hard and not filled with pus. Cysts are filled with pus and feel like fluid filled sacs underneath the skin.
Inflamed acne happens when a plug ruptures a follicle wall and leaks fluid into the skin, which your immune system then responds to with inflammation. if this rupture happens near the surface of the skin, the result is usually a minor papule or a pustule. If it happens deep within the skin, it’s much more likely to become a serious nodule or a cyst (another great reason to never squeeze your skin… you push the bacteria further into your pores, making it more likely for you to get nodules and cysts. And if you do get them, don’t ever, ever, EVER even dare THINK of squeezing this type of acne, although I hope that goes without saying by now).
Nodules is where I’ve gotten confused about my own acne… in the past, whenever my acne started taking a turn for the worst, I would begin getting a lot of big, hard inflamed spots that don’t have heads on them, mostly around my chin. I have never really known if these are actual nodules or just bad papules, because I’ve never had a ginormous one that has lasted for months. I still don’t know the answer.
Either way, I’ve never gotten one of these since I cleaned up my lifestyle!
Terminology
The term acne comes from ἀκνή, a scribal error for the Greek
ἀκμή
(akmē), literally "point, edge", but in the sense of a
"skin eruption" in the writings of Aëtius
Amidenus. Used by itself, the term "acne" refers to the presence
of pustules
and papules. The
most common form of acne is known as acne vulgaris, meaning "common
acne". Many teenagers get this type of acne. Use of the term "acne
vulgaris" implies the presence of comedones. The
term "acne rosacea" is a synonym for rosacea, however,
some individuals may have almost no acne comedones associated with their
rosacea and therefore prefer the term rosacea.[20] Chloracne is
associated with exposure to polyhalogenated compounds.
Signs
and symptoms
Typical features of acne include: seborrhea
(increased oil-sebum secretion), comedones, papules, pustules, nodules (large papules), and possibly
scarring. The appearance of acne varies with skin color. It may result in
psychological and social problems.
Scars
Acne scars are the result of
inflammation within the dermis brought on by acne. The scar is created by the
wound trying to heal itself resulting in too much collagen in one
spot.Physical acne scars are often referred to as "ice pick" scars.
This is because the scars tend to cause an indentation in the skin's surface.
There is a range of treatments available. Although quite rare, the medical
condition atrophia maculosa varioliformis
cutis also results in "acne-like" depressed scars on the face.
- Ice pick scars: Deep pits, that are the most common and a classic sign of acne scarring.
- Box car scars: Angular scars that usually occur on the temple and cheeks, and can be either superficial or deep, these are similar to chickenpox scars.
- Rolling scars: Scars that give the skin a wave-like appearance.
- Hypertrophic scars: Thickened, or keloid scars.
Pigmentation
Pigmented scars is a slightly
misleading term, as it suggests a change in the skin's pigmentation and that
they are true scars; however, neither is true. Pigmented scars are usually the
result of nodular or cystic acne (the painful 'bumps' lying under the skin).
They often leave behind an inflamed red mark. Often, the pigmentation scars can
be avoided simply by avoiding aggravation of the nodule or cyst. Pigmentation
scars nearly always fade with time taking between three months to two years to
do so, although can last indefinitely if untreated.
Cause
Acne develops as a result of
blockages in the follicles. Hyperkeratinization and formation of a plug of keratin and sebum (a microcomedo)
is the earliest change. Enlargement of sebaceous glands and an increase in
sebum production occur with increased androgen (DHEA-S) production at adrenarche.
The microcomedo may enlarge to form an open comedo (blackhead)
or closed comedo. Comedones are the direct result of sebaceous
glands' becoming clogged with sebum, a naturally occurring oil, and dead skin cells. In these
conditions, the naturally occurring largely commensal
bacterium Propionibacterium acnes can cause inflammation,
leading to inflammatory lesions (papules, infected pustules, or nodules) in the dermis around the
microcomedo or comedone, which results in redness and may result in scarring or hyperpigmentation.[2][22]
Hormonal
Hormonal activity, such as menstrual
cycles and puberty,
may contribute to the formation of acne. During puberty, an increase in sex
hormones called androgens cause the follicular glands to grow larger and make
more sebum. Use of anabolic steroids may have a similar effect.[24]
Several hormones
have been linked to acne: the androgens testosterone, dihydrotestosterone (DHT) and dehydroepiandrosterone sulfate (DHEAS), as
well as insulin-like growth factor 1 (IGF-I).
Development of acne vulgaris in
later years is uncommon, although the incidence of rosacea, which may have a
similar presentation, is increased in older age groups. True acne vulgaris in
adult women may be a feature of an underlying condition such as pregnancy, or
disorders such as polycystic ovary syndrome, hirsutism, or Cushing's syndrome. Menopause-associated acne
(known as acne climacterica) occurs as production of the natural anti-acne
ovarian hormones estradiol and progesterone
fail, permitting the acnegenic hormone testosterone to exert its effects
unopposed.
Genetic
The predisposition for specific
individuals to acne is likely explained by a genetic component, which has been
supported by twin studies]
as well as studies that have looked at rates of acne among first degree
relatives. The genetics of acne susceptibility is likely polygenic, as
the disease does not follow classic Mendelian inheritance pattern. There are
multiple candidates for genes which are possibly related to acne, including polymorphisms in TNF-alpha, IL-1 alpha,
CYP1A1 among
others.
Psychological
While the connection between acne
and stress has been debated, scientific research indicates that "increased
acne severity" is "significantly associated with increased stress
levels. Stress is a factor that "can cause an acne flare."
Infectious
Propionibacterium acnes (P. acnes) is the anaerobic bacterium species that is widely
concluded to cause acne, though Staphylococcus aureus has been
universally discovered to play some role since normal pores appear colonized
only by P. acnes. Regardless, there are specific clonal sub-strains of P.
acnes associated with normal skin health and others with long-term acne
problems. It is as yet inconclusive whether any of these undesirable strains
evolve on-site in the adverse conditions or are all pathogenically acquired, or
possibly both depending on the individual patient. These strains either have
the capability of changing, perpetuating, or adapting to, the abnormal cycle of
inflammation, oil production, and inadequate sloughing activities of acne
pores. At least one particularly virulent strain, though, has been circulating
around Europe for at least 87 years. In vitro, resistance of P. acnes
to commonly used antibiotics has been increasing, as well.
Diet
The relationship between diet and
acne is unclear as there is no good quality evidence. However, a high diet is
associated with worsening acne. There is also a positive association between
the consumption of milk and a greater rate and severity of acne. Other
associations such as chocolate and salt are not supported by the evidence. Chocolate does contain a
varying amount of sugar that can lead to a high glycemic load and it can be
made with or without milk. There may be a relationship between acne and insulin
metabolism and one trial found a relationship between acne and obesity.
Parasitic
Positive associations have been
shown with the parasitic mite Demodex, however, the studies to date do not isolate a cause
and it is unclear whether demodex or demodex associated bacteria produces the
effects at this time.
Diagnosis
There are multiple scales for
grading the severity of acne vulgaris, three of these being:
- Leeds acne grading technique: Counts and categorises lesions into inflammatory and non-inflammatory (ranges from 0–10.0).
- Cook's acne grading scale: Uses photographs to grade severity from 0 to 8 (0 being the least severe and 8 being the most severe).
- Pillsbury scale: Simply classifies the severity of the acne from 1 (least severe) to 4 (most severe).
Differential
diagnosis
Other similar conditions include: rosacea, folliculitis,
keratosis pilaris, perioral dermatitis, and angiofibromas
among others.
Management
Many different treatments exist for
acne including benzoyl peroxide, antibiotics, retinoids,
antiseborrheic medications, anti-androgen medications, hormonal
treatments, salicylic acid, alpha hydroxy acid, azelaic
acid, nicotinamide, and keratolytic soaps. They are believed
to work in at least 4 different ways, including: normalizing shedding and sebum
production into the pore to prevent blockage, killing Propionibacterium acnes,
anti-inflammatory effects, and hormonal manipulation.
Medications
Benzoyl
peroxide
Benzoyl peroxide cream.
Benzoyl peroxideis a first-line
treatment for mild and moderate acne due to its effectiveness and mild
side-effects (mainly irritant dermatitis). It works against the "P. acnes"
bacterium, helps prevent formation of comedones, and has anti-inflammatory
properties. Benzoyl peroxide normally causes dryness of the skin, slight
redness, and occasional peeling when side effects occur. This topical does
increase sensitivity to the sun as indicated on the package, so sunscreen use
is often advised during the treatment to prevent sunburn. Benzoyl peroxide has
been found to be nearly as effective as antibiotics with all concentrations
being equally effective. Unlike antibiotics, benzoyl peroxide does not appear
to generate bacterial resistance. Benzoyl peroxide is often combined with
antibiotics.
Antibiotics
Antibiotics are reserved for more
severe cases and decrease acne due to their antimicrobial activity against P.
acnes in conjunction with anti-inflammatory properties. With increasing
resistance of P. acnes worldwide, they are becoming less effective.
Commonly used antibiotics, either applied topically or taken orally, include erythromycin,
clindamycin,
and tetracyclines
such as doxycycline
and minocycline.
Salicylic
acid
Salicylic
acid helps to lessen acne due to its bactericidal and keratolytic
properties. Additionally, salicylic acid can open obstructed skin pores and
promotes shedding of epithelial skin cells. Hyperpigmentation of the skin has
been observed in individuals with darker skin types who use salicylic acid.
Hormones
In females, acne can be improved
with the use of any combined oral contraceptive. The
combinations that contain third or fourth generation progestins
such as desogestrel,
norgestimate
or drospirenone
may theoretically be more beneficial.
Topical
retinoids
Topical retinoids are
medications that possess anti-inflammatory properties and work by normalizing
the follicle cell life cycle.]
This class includes tretinoin, adapalene, and tazarotene.
Like isotretinoin, they are related to vitamin A,
but are administered topically and generally have much milder side effects.
They can, however, cause significant irritation of the skin. The retinoids
appear to influence the cell life cycle in the follicle lining. This helps
prevent the hyperkeratinization of these cells that can
create a blockage. Retinol, a form of vitamin A, has similar, but milder,
effects and is used in many over-the-counter moisturizers and other topical
products. Topical retinoids often cause an initial flare-up of acne and facial flushing.
Oral
retinoids
Isotretinoin
is very effective for severe acne as well as moderate acne refractory to other
treatments. Improvement is typically seen after one to two months of use. After
a single course, about 80% of people report an improvement with more than 50%
reporting complete remission. About 20% of people require a second course. A number of adverse effects may occur
including: dry skin, nose bleeds, muscle pains, increased liver enzymes, and
increased lipid levels in the blood. If used during pregnancy there is a high
risk of abnormalities in the baby and thus women of child bearing age are
required to use effective birth control. There is no clear evidence that use of
oral retinoids increases the risk of psychiatric side effects such as
depression and suicidality.
Procedures
Comedo
extraction may help those with comedones that do not improve with standard
treatment, at least temporarily. A procedure with high patient satisfaction for
immediate relief is the injection of corticosteroids into the inflamed acne
comedone. There is no evidence that microdermabrasion
is effective. As of 2012, evidence for light
therapy and lasers is insufficient to recommend them for routine use. Light
therapy is an expensive treatment modalityand while it appears to provide short
term benefit, there is a lack of long term outcome data or data in those with
severe acne. Laser
surgery can be used to reduce the scars left behind by acne.For people with
cystic acne, boils can be drained through surgical lancing.
Alternative
medicine
Numerous natural products have been
investigated for treating people with acne. Azelaic
acid has been shown effective for mild-to-moderate acne when applied
topically at a 20% concentration. Application twice daily for six months is
necessary, and treatment is as effective as topical benzoyl peroxide 5%,
isotretinoin 0.05%, and erythromycin 2%. Azelaic acid may cause skin irritation
but is otherwise very safe. A topical application of tea tree
oil has been suggested.
Prognosis
Acne usually improves around the age of 20 but
may persist into adulthood. Permanent scarring may occur.
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