Acne: causes and types

Acne is a polymorphic multifactorial disease of hair follicles and sebaceous glands, which occurs in 80% of adolescents and young adults. Among the various clinical types of acne, acne vulgaris is the most common. This dermatosis affects up to 35% of male adolescents and 23% of female adolescents. Only for people over 24 years of age does this figure drop to 10% or lower. According to a psychological survey, 80% of teenagers believe that the most unattractive thing about a person is acne. The presence of acne on visible areas of the skin significantly reduces self-esteem, causes anxiety, depression, and dysmorphophobia (the idea of imaginary external ugliness). Patients suffering from acne find it extremely difficult to adapt to the social environment; among them there is a large percentage of unemployed and lonely people.

Multifactorial disease

Acne is a chronic inflammatory disease of the sebaceous glands that occurs as a result of their blockage and overproduction of sebum.

The term “acne” appeared among specialists not so long ago. He points out that the appearance of acne is not only the appearance of certain eruptive elements, but also a change in the condition of the entire organism. That is why knowledge about this disease is necessary not only for dermatovenerologists and cosmetologists, but also for doctors of all specialties - gynecologists, endocrinologists, urologists, therapists, etc. Acne is a phenomenon characteristic not only of adolescence. Acne can also appear in adults - as a rule, against the background of endocrine diseases, in which the condition of seborrhea occurs. Therefore, if acne is observed in an adult patient, he must be examined to exclude endocrine pathology. Often the clinical picture of acne itself can indicate the presence of a concomitant disease. For example, the location of acne in women around the mouth and on the chin often indicates ovarian pathology (polycystic ovary syndrome or so-called polycystic ovary syndrome). In cases of treatment-resistant acne in adult women, tumors of the adrenal gland or ovary should not be excluded. In men, the main cause of acne is a change in the ratio of various androgens. Acne can also occur while taking various medications, for example, with long-term therapy with systemic corticosteroids (so-called steroid acne). Acne has been described in athletes and bodybuilders taking anabolic steroids (so-called bodybuilding acne). Acne may also occur in persons receiving antiepileptic drugs, barbiturates, antituberculosis drugs (isoniazid, rifampicin, ethambutol), azathioprine, cyclosporine A, chloral hydrate, lithium salts, iodine, chlorine, bromine preparations, some vitamins, especially B1, B2, B6, B12, D2.
There are also exogenous acne, which develop, as a rule, in people with seborrhea when various substances that have a comedogenic effect come into contact with the skin - the ability to cause blockage of the sebaceous glands and increased hyperkeratosis at the mouths of the hair follicles. These include various oils and lubricants, tar preparations. People can come into contact with these substances at work and during skin care. Acne often occurs due to excessive use of cosmetics containing fats (greasy cream powders, blush, eye shadow, etc.). In some foreign classifications of acne, even a special form of acne is distinguished - acne mallorca. This clinical variant was described in young people on holiday in Mallorca who used a tanning oil that was comedogenic, resulting in acne. Therefore, patients with seborrhea are not recommended to use fatty creams or ointments containing fats (lanolin, petroleum jelly) and oils for skin care, and cosmetic products should choose those that are labeled non-comedogenic.

Mechanical acne, which occurs in individuals predisposed to the disease, can also be considered a type of exogenous acne. Their appearance is associated with pressure and friction (simple dermatitis), causing mechanical obstruction of the follicle openings. An example is the prolonged pressure of a headdress, a sports helmet, a plaster cast, or bed linen in immobilized patients, especially with excessive sweating.

Development mechanism

In the pathogenesis of acne, 4 main mechanisms can be distinguished:

• hyperproduction of secretions by the sebaceous glands;
• follicular hyperkeratosis;
• activity of saprophytic microflora of the skin;
• inflammation and microcirculation disorders

Overproduction of secretions by the sebaceous glands is a part of such a pathological skin condition as seborrhea. Seborrhea is not only a quantitative change in sebum production, but also a qualitative one: the content of unsaturated fatty acids decreases and its bactericidal properties decrease. The bacterial flora of the skin is activated and the preconditions are created for the development of an inflammatory reaction and the appearance of acne.

In patients with acne, there is a disruption of the keratinization processes at the mouths of the hair follicles, where the excretory ducts of the sebaceous glands open - follicular hyperkeratosis. Normally, the epithelial cells of the hair follicle funnel become keratinized at a rather slow pace, while the horny scales are peeled off into the lumen of the follicle funnel and come to the surface of the skin along with the secretion of the sebaceous glands. Hyperkeratosis disrupts the outflow and leads to the accumulation of secretions in the sebaceous gland. In the ducts of the sebaceous glands, microcomedones are formed - sebaceous-horn plugs, which do not manifest themselves clinically. Further accumulation of secretion and its pressure on the clogged funnel of the follicle leads to the formation of a cystic cavity in the lower part of the funnel of the hair follicle and the appearance of clinical signs of the disease in the form of closed comedones. The constant accumulation of sebaceous and horny masses inside the follicle and their pressure on the surrounding tissues ultimately leads to atrophy of the sebaceous gland, as well as to an expansion of the mouth of the hair follicle. This is how open comedones (or blackheads) are formed. The secretion of the sebaceous glands, due to the large number of horny scales in it, becomes thick and is poorly removed to the surface of the skin. The black color of that part of the secretion that is visible through the enlarged mouth of the hair follicle is not due to exogenous contamination or oxidation of sebum, as previously thought, but to melanin. Apparently, changes in keratinization processes in the epithelium, and partly cell proliferation, somehow affect melanogenesis in this area.

According to modern concepts, bacteria are not the direct cause of the disease; they only provoke local inflammatory processes. Saprophytic microorganisms such as lipophilic fungi of the genus Pytirosporum, Staphylococcus epidermidis and Propionibacterium acnes are constantly present on the skin and hair follicles. The largest role in the development of inflammation in acne is played by Propionibacterium acnes - gram-positive, non-motile lipophilic rods that are facultative anaerobes. The blockage of the mouth of the hair follicle and the accumulation of sebum inside it create the preconditions for the proliferation of these microorganisms inside the funnel of the hair follicle. The constant proliferation of P. acnes in the follicle, which is detected at the microcomedone stage, leads to an increase in the activity of metabolic processes, which results in the release of inflammatory mediators. For example, during the life of P. acnes, they secrete lipases that break down sebum triglycerides into fatty acids, which cause damage to the follicle epithelium. Proteolytic enzymes secreted by P. acnes also have a damaging effect on the epithelium.
In the earliest stages of acne, P. acnes and their metabolic products cause inflammation in the dermis. There is a migration of lymphocytes to the site of inflammation. Subsequently, complement activation occurs, the mediator of which is the cell wall of P. acnes itself, positive taxis of neutrophil leukocytes to the lesion occurs, as well as the synthesis of antibodies against P. acnes. Neutrophils, secreting lytic enzymes, contribute to even greater damage to the follicle epithelium. As a result of the inflammatory reaction, free oxygen radicals, hydroxyl groups, and superoxides of hydrogen peroxide accumulate in the dermis. They further damage cells and support inflammation. In addition, the contents of the follicle, due to impaired permeability of the epithelium, enter the dermis and also cause an inflammatory reaction as a kind of foreign substance. Therefore, at a later stage of acne development, macrophages, giant cells and blood vessels are involved in the process.

One of the main links in the pathogenesis of acne is microcirculation disorders. Skin vessels have the ability to quickly and variedly respond to the action of certain stimuli, which is based on the phenomena of vasoconstriction and vasodilation caused by vasomotor nerves. This especially applies to skin areas with a large number of arteriovenular anastomoses (face). Where there are none or few of them, vasodilation and vasoconstriction are caused by the state of basal vascular tone.

In acne, the initial hyperemic reaction of the skin is gradually accompanied by stagnation of blood in the venules and spasm of the afferent vessels, followed by the development of microangiopathies and blood stasis. It must be emphasized that the progression of acne is characterized by dynamic changes in the vessels of the microvasculature (MCR). Already at the early stages of the disease, compensatory-adaptive processes develop in the form of opening of existing MCR networks, the formation of intervascular anastomoses, and an increase in the number and expansion of lymphatic terminals. This ensures adequate vascularization, gas exchange in tissues and removal of metabolites. With a long course of the disease, a significant reduction of the capillary network, restructuring of post-capillaries and venules, and their dystonia are observed, which play a significant role in the development of hemodynamic and metabolic disorders.

It should be emphasized that inflammation can develop at any stage of acne and be superficial or deep, which causes a variety of clinical manifestations.

Clinical picture

In the clinic of the disease, the following types of acne are distinguished:

• comedones (comedo sou acne comedonica);
• papular and papulopustular acne (acne papulosa et papulopustulosa);
• acne indurativa;
• phlegmonous acne (acne phlegmonosa);
• conglobate or piled acne (acne conglobata);
• acne fulminans;
• acne inversa or hidradenitis suppurativa.

Comedones are non-inflammatory elements resulting from blockage of the mouths of hair follicles. It should be emphasized that slightly pronounced comedones are a physiological phenomenon. At the beginning of the development of acne, microcomedones transform into so-called “closed” comedones, that is, those that do not have free communication with the surface of the skin. They are non-inflammatory nodules of dense consistency with a diameter of up to 2 mm. The gradual increase in volume of these nodules due to the constant production of sebum creates conditions for the transformation of some of them into “open” comedones (blackhead acne).
Papular and papulopustular acne are a consequence of the development of inflammation of varying severity around open or closed comedones. In mild forms of the disease, papulopustular acne resolves without scarring. With a significant severity of the inflammatory reaction, accompanied by damage to the structures of the dermis, scar formation is possible at the site of the inflammatory elements.
Describing the various manifestations of acne, one cannot fail to mention its special type - excoriated acne. These are acne that occur mainly in patients who tend to excoriate even minimal rashes. In this case, excoriations can occur against the background of pre-existing acne or without them. This clinical form may be associated with obsessive-compulsive neurosis, or indicate a more severe psychiatric pathology. Therefore, it is advisable to consult a psychotherapist or neuropsychiatrist for patients with excoriated acne.

In most patients, the rashes belong specifically to the categories acne comedonica and acne papulopustulosa. All other types are relatively rare, but no less important - either due to the severity of the course, or because they require a different approach to therapy.
Indurative acne is characterized by the formation of deep infiltrates; the outcome of this condition is always the formation of scars. In some cases, in places of infiltrates, cystic cavities filled with pus are formed, which can merge with each other. This type is called phlegmonous acne. A prolonged course of this form of the disease is usually observed. Often indurative and phlegmonous acne is called nodular cystic. Nodular cystic acne is a sign of a rather severe course of acne.

Conglobate acne also indicates a severe course of acne. They are characterized by the gradual appearance of multiple extensive, deeply located nodular-cystic elements that communicate with each other, as well as large grouped comedones. Lesions can be located not only in seborrheic areas, but also involve the skin of the back, abdomen, and limbs, with the exception of the palms and soles. The outcome of the resolution of most elements is atrophic, hypertrophic and keloid scars. The manifestations of this disease, as a rule, do not decrease after puberty; they can recur until the age of 40, and sometimes throughout life.

Acne fulminans is a rare and severe form of acne. The disease occurs more often in young men aged 13–18 years, suffering from mild papulopustular, less often nodular-cystic form of acne, and is characterized by a sudden onset, the appearance of ulcerative-necrotic elements (mainly on the trunk) and general symptoms. Some authors consider acne fulminans as an acute ulcerative variant of acne conglobata, but most researchers believe that this form of the disease is closest to pyoderma gangrenosum. The etiology of acne fulminans is not entirely clear. It is assumed that infectious-allergic or toxic-allergic mechanisms play a role in the pathogenesis of the disease. Acne fulminans is known to occur in patients with severe chronic diseases (Crohn's disease, ulcerative colitis, etc.). However, it was noted that some patients, before the onset of acne fulminans, took tetracycline antibiotics, synthetic retinoids, and androgens.

The disease develops quickly. The clinical picture is dominated by intoxication phenomena: almost always there is an increase in body temperature above 38 ° C, the general condition of the patient is disturbed, arthralgia, severe muscle pain, abdominal pain occur (these phenomena subside while taking salicylates), weight loss, anorexia. The appearance of erythema nodosum, hepatosplenomegaly has been described, and in some patients osteolytic processes develop in the bones. A clinical blood test reveals leukocytosis, sometimes even a leukemoid reaction, accelerated ESR and decreased hemoglobin. Blood cultures are usually negative. On the skin of the back, chest, lateral surfaces of the neck and shoulders, pustular rashes appear on an erythematous background, as well as numerous rapidly ulcerating papular elements. Characterized by the absence of rashes on the face. Healing of lesions is often accompanied by the formation of many scars, including keloids.

There is no uniform classification of the severity of acne. However, most researchers distinguish three degrees of severity:

• mild - the presence of mainly closed and open comedones with virtually no signs of inflammation. With a mild degree, there may be less than 10 papulopustular elements on the skin of the face. The process extends beyond the T-zone;
• medium – from 10 to 40 papulopustular elements on the skin of the face;
• severe - more than 40 papulopustular elements on the skin of the face, as well as abscess, phlegmonous (nodular-cystic) or conglobate acne.

Recently, an increasing role has been given to assessing the psychosocial status of a patient with acne. It is known that acne has a significant psychological impact on the patient, causing anxiety, depression, social maladjustment, interpersonal and work difficulties. These points should be clarified during a conversation with the patient for possible psychotherapeutic or medicinal correction of the identified features.

Physiotherapeutic treatment

Modern approaches to the treatment of acne include the prescription of various systemic and external drugs, antiandrogenic drugs that affect the pathogenesis that has been well studied to date: hyperplasia and hypersecretion of sebum, follicular hyperkeratosis. Of course, the choice of treatment for acne should be based on an adequate clinical assessment of the severity, as well as the type of skin rash. To achieve maximum results, the principle of an integrated approach is often used. And, of course, hardware techniques are widely used in the treatment of acne. With their help, you can not only improve the appearance of the skin, but also stimulate blood circulation, enhance lymphatic drainage, stimulate metabolism, and improve the nutrition of skin cells. Depending on the type of acne, different types of physical therapy are used (Table 1).

Table 1. Pathogenetic treatment of acne using physiotherapeutic methods

Broadband pulsed light

To date, there is no method that can claim universality. The newest and most promising methods for treating acne include phototherapy (Table 2). One of the effective modern photo technologies is LHE light and thermal energy technology using the Clear Touch acne treatment system, developed and patented by Radiancy. What is the mechanism of action of technology on acne? Under conditions of lack of light and oxygen and excess sebum, colonization of P. acnes, which are lipophilic anaerobes, increases. Destruction of the walls of the hypertrophied sebaceous gland under the influence of P. acnes enzymes with increasing internal sebum pressure causes activation of a cascade of immune reactions leading to the development of inflammation. LHE technology uses a specially selected composition of inert gases, which makes it possible to use the light range from green to infrared (from 600 to 900 nm). In this case, the yellow and green parts of the spectrum penetrate to the depth of the sebaceous gland and are absorbed by the chromophore porphyrin, a waste product of P. acne. During this chemical reaction, atomic oxygen is released, causing peroxidation of the bacterial walls. Radiation from the infrared region of the spectrum has an anti-inflammatory effect, and also helps to open pores, improve microcirculation, and activate phagocytosis.

Table 2. Phototechnologies in the treatment of acne

The energy flux density not exceeding 10 J/cm2 and the pulse duration of 35 ms make it possible to completely avoid thermal burns.

This combination of properties of this phototherapy makes it possible to achieve a positive clinical result relatively quickly. The course of therapy using the system is 4–8 weeks. As usual, patients receive 2 sessions per week with an average duration of 20–30 minutes. The procedures are well tolerated by patients and practically do not interrupt them from their daily activities, which, combined with the effectiveness of the method, significantly improves their quality of life.

No side effects were observed in practice. Immediately after the procedure, mild transient erythema develops. In rare cases, after the first 2-3 procedures, an exacerbation reaction is possible, the appearance of fresh papular rashes, which is associated with massive destruction of bacteria and the acceleration of the evolution of morphological elements. Subjective sensations are practically absent or limited to a mild burning sensation in the area of the rash, which passes very quickly.

Clinical improvement in the course of the disease is observed in 40–50% of patients already in the second or third procedure, and resolution of most papulopustular elements is recorded mainly by the 3–4th week of treatment. The effectiveness of the course of therapy is estimated to be up to 90%.

LHE therapy for acne does not exclude the use of combination treatment and the use of external agents.

Laser therapy

An alternative treatment for acne is laser therapy. Currently, there are different types of lasers used to treat acne. They differ both in output characteristics and in the interaction of their radiation with tissues. One of the principles that ensures the success of acne treatment can be considered the effect on pathologically altered blood vessels, which can radically affect the morphofunctional state of microcirculation in inflamed areas of the skin and the absorption of transmitted laser energy by the protein structures of the shell of microorganisms.

The neodymium laser is the most deeply penetrating laser: with a spot diameter of 8 mm, penetration into tissue is 6 mm. The laser beam is proportionally absorbed by five chromophores: deoxyhemoglobin, oxyhemoglobin, protein, water (15% absorption) and melanin (10% absorption).

The methodology for acne treatment procedures when using a Nd:YAG laser block is based on the use of the phenomenon of homogeneous photothermolysis at a depth of up to 4 mm. Treatment of acne lesions using an Nd:YAG laser block is pathogenetic due to the direct sterilization of inflammation, normalization of microcirculation by coagulation of blood vessels in the area of inflammation and stimulation of trophic processes by enhancing revascularization. The procedure is performed on an outpatient basis, without the use of anesthetics, using the recommended parameters:

Table 3. Nd:YAG laser parameters for acne treatment

Due to the pathogenetic nature of the treatment method, procedures are carried out daily for 3 days at the limit of the patient’s individual tolerance, since the larger the size of the uniform element, the more energy will be required to warm it up and sterilize it. The effectiveness of treatment is assessed the next day by reducing the severity of signs of inflammation. After regression of the formed elements, the procedures are stopped. For severe forms of acne, a repeat course of 3 procedures is performed every 3–5 days.

The active introduction of “high technologies” into clinical practice opens up new opportunities for doctors and their patients. For the treatment of acne, a variety of devices are presented on the modern aesthetic medicine market.

Thus, physiotherapeutic methods, considered auxiliary in clinical medicine, have become one of the main ones in aesthetic medicine. Due to their effectiveness and speed of achieving results, they have won many fans, including in the treatment of acne.

Literature:

• Irina Bragina is a doctor of the first category, physiotherapist, dermatocosmetologist, consultant doctor at the training center of the SportMedImport Group of Companies (Russia, Moscow).
• KOSMETIK international journal, №4(38)