How to recognize different types of skin imperfections?

The term "imperfections" is often misused. It is sometimes used to refer to areas of the skin that are dry or shiny, or even a dull complexion. However, it actually refers to small temporary impurities, caused by specific factors, which can appear on the face and certain parts of the body.

Similarly, when discussing skin imperfections, the term acne is most frequently used. However, there are many other skin issues associated with imperfections, which can appear at any age. Among those commonly encountered, we have:

• Visible Pores : Enlarged pores are defined as a skin imperfection. Indeed, they are dynamic structures whose size can fluctuate, although it is genetically determined. Thus, enlarged pores manifest as a micro-depression on the surface of the facial skin with a "tangerine skin" appearance. According to a study, skin pores are said to be "visible" and "enlarged" when their diameter oscillates between 0.06 and 0.1 mm2.

  This increase in pore size can be associated with three potential factors, namely an increased sebum production, a loss of skin elasticity with age or an increase in the size of hair follicles (thickness of the hair). This dilation makes the pores more likely to become clogged, leading to the formation of comedones and pimples. Most enlarged pores are found on the nose and the medial aspects of the cheeks;

  

• Blackheads (open comedones): Blackheads are classified as a common form of non-inflammatory mild acne. They are easily recognizable by their black color, which comes from the melanin contained in the sebum that oxidizes when in contact with the surrounding air, forming a black plug on the surface of the pilosebaceous follicle.

  Particularly stubborn and difficult to remove, blackheads form as a result of the obstruction of skin pores by an excessive secretion of sebum (hyperseborrhea) and/or dead cells (hyperkeratosis). They primarily appear in the T-zone of the face, which includes the area around the nose, the forehead, and the chin, parts of the skin with the highest concentration of sebaceous glands. Often confused with sebaceous filaments, it's important to accurately distinguish between the two.

  

• Whiteheads (closed comedones)) : Whiteheads appear as small bumps, typically less than 3 mm in diameter, almost invisible to the naked eye. They are flesh-colored, round, raised, and non-inflamed, caused by the clogging of follicular openings due to an excess of dead skin and sebum.

  They typically appear around the hairline, on the upper cheeks, and on the chin, but can be found anywhere on the body. Unlike blackheads, closed comedones form beneath the skin's surface, thus preventing their oxidation. However, if they are picked at or if conditions are conducive to infection, they can develop into a papule or a pustule;

  

• Papules (red bumps): Papules are the most common but less severe inflammatory acne lesions. They appear as small red protrusions, due to inflammation, with a diameter less than 1 cm, and do not contain purulent material.

  They form when sebum, unable to flow freely, accumulates in the hair follicle, creating an environment conducive to the colonization of the bacteria Cutibacterium acnes, formerly listed under the name Propionibacterium acnes, but also causes the rupture of the pore walls to which the skin responds with a visible inflammatory response ;

• Pustules (white bumps) : Unlike papules, pustules are small bumps, measuring between 5 and 10 mm in diameter, with a white or yellow center filled with pus due to its composition of inflammatory cells, a sign of a bacterial, fungal, or viral infection, and a red perimeter.

  Their cause? An accumulation of sebum and keratinocytes, and the proliferation of the bacteria Cutibacterium acnes, just like papules. Although they can easily resolve, they tend to recur;

  

• Nodules: Present in the most severe forms of acne, nodules are dome-shaped infected lesions, palpable to the touch, larger in size (measuring approximately 1 - 6 mm in diameter), flesh-colored, white or red, which can be physically painful, and develop deep within the skin. They generally heal with scarring. Their appearance involves increased activity of the sebaceous glands, abnormal keratinization of the follicles, the action of microorganisms, and subsequent inflammation;

  

• Cysts: Much like nodules, cysts are considered a form of severe acne. Generally painless, these are thin-walled tissue pockets containing fluid or semi-fluid matter with an epithelial lining, and they develop deep within the skin. However, a rupture in the microcyst wall can make it sensitive to touch and cause inflammation, leading to the appearance of a red and purulent pimple;

• Brown Spots : Acne and blackheads are not the only skin imperfections we may encounter. The pigment spots, which include solar spots, melasma , and post-inflammatory hyperpigmentation marks, are also considered skin imperfections. They appear as flat, asymptomatic spots ranging in color from light brown to dark brown, typically with irregular edges and varying in size from a few millimeters to several centimeters in diameter.

  This abnormal skin pigmentation results either from an increase in melanin content by melanocytes, or from an abnormal distribution of it in the skin. Spots most often appear on the face, the back of the hands, the décolletage, or in the folds of the skin. This disorder is favored by various factors such as sun exposure, hormones, or even repeated skin friction ;

  

• Residual Scars: Beyond pimples and dark spots, scars are also considered as skin imperfections. It happens that some acne pimples leave lasting marks, especially if they have been handled improperly. These scars form when new collagen develops rapidly and deposits to heal an inflammatory lesion and prevent infection. Unfortunately, acne scars never completely disappear, even though their appearance tends to generally improve over time. Ice pick, atrophic (indented), hypertrophic (raised)... there are different types of acne scars.

  

Until today, it is commonly believed that poor daily hygiene is the main cause of these skin issues. However, this is not always the case. Other triggering factors, internal or external, can contribute to a blemished skin, such as:

• Hereditary Predisposition: Genetics and family history appear to play a dominant role in the onset of acne, particularly severe acne. Indeed, several studies show that acne appears earlier and is more severe in individuals with positive family histories. One study even identified two new loci, 11p11.2 and 1q24.2, which are implicated in the metabolism of androgens, inflammatory processes, and scar formation in severe acne, thus highlighting another risk factor that influences acne.

  There is also a clear genetic predisposition in patients with melasma, a common form of hyperpigmentation. Indeed, 60% of affected individuals report that family members also suffer from it. Similarly, genetics largely determine the size of skin pores;

• Skin Type: Combination to oily skin types are most likely to exhibit blemishes such as blackheads, comedones, or pimples, as they secrete more sebum than normal, creating a favorable environment. Of course, they can also appear on other skin types under the influence of several factors;

• Aging: As we age, the skin loses its elasticity, causing the skin around the pores to become less tight. This can lead to an increase in their size, making them more visible.

  Furthermore, as we age, the skin's cellular renewal process slows down. Consequently, dead cells remain on the skin's surface instead of shedding, leading to their accumulation, the clogging of pores (and also their enlargement), and thus the formation of blemishes;

• Hormonal Disorders: Hormones are one of the main causes of skin imperfections. For instance, during puberty, the body produces more male hormones (testosterone, androgen), which in turn boosts the production of sebum in the sebaceous glands. As a result, men tend to suffer more from acne during adolescence than women. However, in adulthood, women are more affected by acne than men, which can be largely attributed to a hormonal component.

  While their levels stabilize over the years in men, in women, they continue to fluctuate, particularly with the onset of menstruation (premenstrual syndrome), during pregnancy, at menopause, or following the cessation of hormonal contraception. A study has shown that a high serum level of progesterone, but a low level of estrogen, was found in patients suffering from common acne.

  UV rays are not the only factors that promote the appearance of brown spots on the skin. Hormonal factors also play a role in skin pigmentation defects. Studies have shown that under the influence of female hormones, namely estrogen and progesterone, an over-stimulation of melanocytes is observed;

• Chronic sun exposure: Overexposure to the sun can cause dehydration and dry out the skin. In response to this imbalance, the skin will start to produce more sebum. Similarly, indirectly, the sun is also a risk factor in the dilation of skin pores. It weakens the structure of the dermis by damaging the collagen and elastin fibers. Less firm and flexible, the dermal structure surrounding the pores then collapses and their size widens.

  Ultraviolet rays are also the main exogenous factor capable of altering the normal pigmentation of the skin. In response to the mutagenic effects of the sun's UV rays, the skin secretes melanin to protect the nucleus, and therefore the DNA, of the keratinocytes in the basal layers of the epidermis, acting as a natural sunscreen. Furthermore, the penetration of the sun's UV rays leads to an increased production of free radicals, which would stimulate the production of melanin to protect cells from their harmful effects;

• Imbalanced Diet: There is evidence that diet can promote the development of acne. Indeed, studies have evaluated the impact of the glycemic index of various foods on the skin, revealing that individuals following a high glycemic load diet have more acne lesions. This is caused by a significant production of insulin to lower blood sugar levels, which in turn increases androgen levels, thereby promoting sebum secretion.

  Similarly, several studies have demonstrated a positive association between dairy product consumption and acne prevalence. More specifically, they have shown that whey proteins and casein could contribute to the development or worsening of acne, by triggering sebum production. Furthermore, acne can be caused by the consumption of foods high in free fatty acids, which can promote the proliferation of P. acnes .

• Sleep Quality: Getting less than 8 hours of sleep per day could be a risk factor for acne. Indeed, studies have shown that a lack of sleep (sleep duration ≤ 5 hours) is correlated with an increase in transepidermal water loss compared to individuals with good sleep quality (sleep duration between 7 - 9 hours), indicating an impairment of the skin barrier. In such a situation, the skin's defense system against external aggressions becomes weakened, which can lead to skin problems like acne, but also an increase in sebum production;

• Touching the face: Generally speaking, we touch our faces about 3,000 times a day, although this varies from person to person. However, our hands come into contact with numerous surfaces throughout the day that harbor bacteria and other dirt that are not good for the skin. This can potentially lead to an increase in skin imperfections. Similarly, handling and popping pimples significantly increases the risk of damaging the skin and thus promotes the formation of scars.

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