The role of the beautician in reducing striae

Striae distensae are a permanent skin defect that can affect 50%–90% of the population. The appearance of the changes resembles spindle‐shaped skin bands. The skin in this area is wrinkled, thin and looks like a scar. Most often, the changes are found on the skin of the abdomen, buttocks, breasts, thighs, and back. The appearance of striae means that the skin in this area has no hair follicles, sebaceous, and sweat glands. This skin is flabby, not very elastic and, what is very characteristic, the pigmentation of the skin affected by striae is much lower than in healthy skin. Cosmetology in the 21st century is developing very dynamically, new technologies are being developed, new cosmetological devices are being created and combined with treatments that have been known for a long time. Today's science offers hope for people who have struggled with reducing striae for many years and nowadays, nothing is impossible.

dermis.Blood vessels dilate and lymphatic infiltrates appear in their lumen.In histopathological terms, striae have common features with scars, as they are filled with fibrous connective tissue.The next stage, called atrophic or maturation, is the stage when there is no more inflammation and the striae distansae become milky white (striae alba [SA]).The connective tissue contains collagen fibers (degraded) and highly branched elastin fibers.[3][4] This defect is more common in women than in men and seen in about 90% of pregnant women.The causes of striae distansae include severe and mechanical stretching of elastin and collagen fibers.Genetics, puberty, previous pregnancies, Cushing's syndrome and chronic liver disease also play an important role.Obesity and anorexia are diseases that also contribute to the development of the above changes.Lesions occur not only in adults, but also in children and adolescents on the thighs, hips, buttocks, and back.Striae distansae are very common in athletes and bodybuilders who experience excessive growth of muscle mass.People taking glucocorticosteroids are also predisposed, as these drugs interfere with the proper proliferation of fibroblasts and lead to decreased production of hyaluronic acid, collagen, and chondroitin sulfate.[7][8]

| COS ME TOLOG I C AL AND AE S THE TI C S TRE ATMENTS
Cosmetology is an interdisciplinary field that combines knowledge from different sciences such as medicine, chemistry, and biology.It is a science whose task is not only skin care, but also the reduction of skin defects.Striae are a very difficult skin problem, but today's cosmetology is at the highest level and offers a range of advanced treatments with devices that can almost completely reduce striae.
In this review, we presented the most frequently used methods in beauty salons, which are also the basis of many scientific studies.A systematic review of the literature was undertaken using Medline and Google Scholar.

| Lasers
Lasers are devices that target chromophores found in the skin.These include: water, hemoglobin, and melanin.Various types of lasers are used to reduce striae, including ablative, and non-ablative.

| Ablative lasers
Ablative lasers cause tissue ablation thanks to the short-term exposure to a high-energy laser beam.They also vaporize the skin, which leads to the formation of the microablation zone.The intact cells stimulate stem cells to rebuild the damaged skin areas.Ablative lasers are characterized by wavelengths from 2940 to 10 600 nm.
They are aggressive devices, the skin is highly irritated (red) after the procedure, swelling or post-inflammatory discoloration may occur, and patients require a convalescence period of several weeks after the procedure. 9 should be emphasized that very good results are observed in combination with other cosmetic treatments.Naeini et al. performed a study using a fractional CO 2 laser (10.064 nm) and a combination of fractional CO 2 laser and PDL (Pulsed dye Light) to reduce SA (striae alba).Eighty-eight lesions in three women were included in the study.Group 1 was treated with a fractional CO 2 laser, while Group 2 received combined CO 2 and PDL laser treatment.It was found that there was a reduction in SA in both group 1 and group 2, but better results were observed in group 2. 10 Another study conducted by the researchers looked at the injection of PRP and the combination of this method with a fractional CO 2 laser (FrCO 2 ) compared to its combination with a pulsed dye laser (PDL) in the striae distensae.Thirty patients participated in the study.The treatment protocol consisted of injecting PRP on both sides of the body, then using a fractional CO 2 laser on the left side and PDL on the left side.A total of three treatment sessions were performed, and the intervals between them were 6 weeks.Studies have shown that combining a fractional CO 2 laser with PRP gives better results than using PRP with PDL. 11ein et al. conducted studies in which SA (striae alba) were reduced in women.In group 1, five treatments with FrCO 2 were performed 2-4 weeks apart, and in group 2, glycolic acid (10%) and tretinoin cream (0.05%) were smeared on the striae every night.
Better results were obtained in group 1, in which the patient's skin was reprocessed. 12sphanurat et al. compared the efficacy of a fractional CO 2 laser combined with a growth factor (rhEGF) and a fractional CO 2 laser and aloe vera gel on SA.The study involved 24 patients were divided into a right and a left side.Each participant received three laser treatments 4 weeks apart.After the procedure, patients had to smear the randomly assigned areas with rhEGF growth factor or aloe vera gel.Better results were obtained when a fractional CO 2 laser was combined with growth factor. 13actional ablative lasers include the Er:YAG laser.Wanitphakdeedecha et al. enrolled 21 women with striae distensae in their study.The subjects' changes were divided into two sides.One side was subjected to "a pass of 400 mJ in short pulse mode (SP) with 50% overlap and a pass of 2.2 J/cm 2 in smooth mode (SM) without overlap."The other side of the striae distensae was treated with two passes of 400 mJ in SP mode with a 50% overlap.There were no differences between the two sides, and the effects were comparable. 14

| Non-ablative lasers
The most commonly used non-ablative lasers for striae include: Erbium glass laser (Er:glass), PDL, and Nd:YAG 1064 nm.The erbium glass laser was used by Gokalp to reduce striae.Sixteen patients with abdominal lesions participated in the study.The treatment series consisted of five sessions per-formed every 4 weeks.The study showed that the average width of striae decreased significantly after the treatments, proving that this type of treatment is effective in reducing striae distensae. 15leski-Larsen et al. studied the effect of an Er:glass laser with a wavelength of 1565 nm and a fractional picosecond laser (Nd:YAG) in the treatment of SA (striae alba).Twenty patients with lesions on the abdomen were included in the study.One side was treated with an Er:glass laser and the other side of the abdomen was treated with a fractional Nd:YAG laser (1064/532 nm).Three treatments were performed 3 weeks apart, and the study results showed that both lasers were equally effective in treating SA, only the patients rated the picosecond laser as less painful. 16okeir et al. used a PDL laser and IPL (Intensive Pulsing Light) to check their effectiveness in the case of striae distensae.Twenty people took part in the study.In the study, PDL was used on one side of the body and IPL on the other.Five treatments were performed every 4 weeks.The study showed that both lasers reduced the width of the lesions and improved the skin texture.There was also an improvement and increase in collagen expression, but in this case PDL turned out to be a better laser. 17saie et al. tested the Nd:YAG laser at different powers (75 and 100 J/cm 2 ) on 45 subjects with striae (striae alba and striae distensae).Each subject received four treatments at three-week intervals.
For SA, better results were obtained with a dose of 100 J/cm 2 , while for striae distensae, a dose of 75 J/cm 2 resulted in better flattening of the lesions.Researchers have concluded that the Nd:YAG laser is a safe and effective device for combating skin striae. 18-Ramly et al. decided to use histologic and quantitative morphometric testing to determine whether Nd:YAG laser therapy would be effective in reducing striae.Forty patients with striae distansae and SA were enrolled in the study.Four treatments were performed at monthly intervals, and a skin biopsy was taken from each patient.Histological examination showed an increase in the amount of collagen and a decrease in the average percentage of elastin fibers surface area.The study showed that the clinical treatment of striae was not statistically significant. 19

| Intense pulsed light
Intense pulsed light (IPL) is not a laser, but a device that uses visible light.IPL is characterized by the absence of a fixed wavelength (which is strictly defined for lasers) and has scattered light beams.
The lamp has a high intensity and a frequency spectrum in the range of 500-1200 nm.
Scientists have frequently used the device IPL for their studies.
Al-Dhalimi M.A. et al. tested two wavelengths used in the device to see which of them would give better results in reducing striae.
Twenty patients with striae distensae participated in the study, and the left and right sides of the body were irradiated with waves of 590 or 650 nm.Treatments were given every 2 weeks, and there were five treatments in total.The results of the study were statistically significant.It was found that the 590-nm wavelength was more effective than the 650-nm wavelength in reducing striae distansae. 20rnández-Pérez et al. used IPL on 15 women.The striae of the subjects were in an advanced stage, which could also be difficult to remove.All subjects received five treatments with a 2-week break, and a skin biopsy was also performed before and after the treatment series.A series of treatments reduced striae, showing that it was a safe treatment. 21searchers have also tried combining IPL treatments with other devices.Wang et al. additionally used erbium fractional laser for striae gravidarum (SG).The research group consisted of 60 patients who were first treated with IPL and then with a fractional erbium laser with a wavelength of 2940 nm.In the treatment series, three treatments were performed at a monthly interval.The test results proved to be statistically significant, the area of striae was reduced, and the elasticity and thick-ness of the skin increased significantly.
In addition, patient satisfaction with the tests was studied, which was 96%. 22

| Fractional radiofrequency (FRF)
In fractional radiofrequency (FRF) treatment, a radio wave beam is pierced into the skin, heating the skin along the entire length of the needles.A thermal and mechanical stimulus is created, which stimulates fibroblasts to produce new elastin and collagen fibers.The fibers shorten and thicken, causing the striae to fill in and disappear.
Adatto M. studied a group of 17 patients who underwent FRF.
Each patient received four treatments at monthly intervals.The treatments were performed on the buttocks, arms, and thighs.Using 3D photos taken with a 3D camera, we were able to determine whether the treatments reduced striae before the treatment series and after 12 and 16 weeks.Subjects also completed special patient satisfaction questionnaires.The research results were extremely promising, as the volume of striae decreased by an average of 19.1%.
Redness also decreased by 14.3%.Patients were also satisfied and happy with the results of the tests. 23u et al. conducted a study to evaluate the efficacy of a new drug for striae using beta-glucan in combination with nanoFRF.The study involved 64 women who had pregnancy-related white or silver striae on their abdomens.They were divided into four groups: group A (blind group), group B (current product group), group C (product combined with nanoFRF), and group D (vehicle combined with nanoFRF).Before starting the treatment series, each patient's striae width, collagen density, skin thickness, and skin color were measured.The research showed that the best results were observed in group C, where the synergy of the nanoFRF treatment and the preparation with β-glucan was used. 24her researchers investigated whether FMR and the combination of this treatment with freeze-dried growth factors worked better than FMR alone in reducing SA.The study involved 25 patients who had striae on their abdomen.The treatment series consisted of four treatments performed every 4 weeks.FMR with growth factor was performed on one side of the abdomen, and FMR with saline was performed on the other side.A biopsy was performed on each patient and photo-graphically documented.The results of the treatment series clearly showed that at the site where radio wave treatment with freeze-dried growth factor was performed, the results in terms of reduction and smoothing of lesions were better than at the site where FMR and physiological saline were used.As for the biopsy results, there was no difference in epidermis thickness, collagen or elastin content in both groups. 25ny et al. included 10 patients with SA in their study.Three different treatment sites were selected for each subject.The first site received treatment with platelet-rich plasma (PRP), the second site received CO 2 and RF lasers, and the third site received the therapies of the first and second sites.The treatments included three sessions, and the interval between them was 1 month.A skin biopsy was taken from each patient, as well as photos of the striae before and after the treatment series.The best improvement was obtained by combined treatments, i.e., fractional CO 2 treatment, RF, and PRP.There was an increase in the amount of collagen and a decrease in elastin, while single treatments showed a decrease in collagen and elastin.The research results have shown that the synergy of several methods is a better solution for striae than their separate application. 26other study, performed on 14 women from China who had pregnancy-related striae, aimed to verify the efficacy of the nonablative fractional laser-NAFL (1565 nm) and MRF.The procedure was performed on the abdomen, with the NAFL randomly applied on one side and the MRF on the other.Each subject received three treatments at 6-week intervals, and skin melanin index and histological examination were performed to evaluate the effectiveness of the treatments.The results of the study showed that the MRF treatment gave better results in terms of the appearance of striae, but was more painful for the patients.Histological examination showed that the amount of neocollagen and elastin fibers increased significantly during MRF treatment. 27da et al. investigated the effect of fractional Er:YAG laser and microneedling radiofrequency (RF) at the atrophic stage (striae ditansae).
For this purpose, 20 women were enrolled in the study and fractional laser (2940 nm) was applied on one randomly selected half of the body and MRF on the other side.The study results showed that there was no significant difference between the treatments and both showed significant reduction at the widest site.Er:YAG and MRF lasers have been shown to be effective and safe methods for reducing striae. 28

| Platelet-rich plasma (PRP)
PRP is a treatment in which we use the body's own serum, which contains a high concentration of platelets and growth factors.This method is used in dermatology to treat baldness, rejuvenate the skin and combat acne scars.Many scientists are also conducting advanced research on the effects of PRP on reducing striae. 29 Padula et al. wanted to analyze fibroblasts in striae rubrae (SR) in the inflammatory phase and striae alba (SA) in the chronic phase.
They decided to apply two therapies with different concentrations of PRP and sodium ascorbate.The research results showed that a higher concentration of PRP and sodium ascorbate led to a resumption of metabolic activity thanks to the production of type I collagen and cell proliferation. 30nergy of treatments is very popular in science, and many studies have shown that combining two treatments is much more effective than performing single treatments.Gamil et al. studied the effect of an intralesional injection PRP compared to topical treatment with 0.05% tretinoin.Thirty patients who had striae on both sides of the body participated in the study.One side of the body was treated with PRP and the other side was smeared with tretinoin.
Each subject had a skin biopsy taken before and after on the treated areas.A series of treatments showed that both treatments reduced striae, but greater improvement was observed with the PRP treatment.The biopsy showed that the number of collagen and elastin fibers increased on both sides of the body. 31ser treatments have long been known by dermatologists and cosmetologists, which is why they are becoming increasingly popular and are combined with treatment PRP, among others.Sayed et al. used fractional CO 2 laser treatment itself and the synergy of this treatment with PRP in the treatment of striae (SR and SA).Thirty women were enrolled in the study, and were divided into group A (fractional laser and PRP) and group B (fractional laser).A skin biopsy was performed before and after treatment for histopathological evaluation.A series of treatments showed that there was a significant increase in collagen and elastin fibers in both group A and group B. The results were positive.However, the combined treatments were statistically more significant and the improvement was better than in the group with fractional laser alone. 32other group of researchers decided to test which therapeutic interventions would have a better effect on reducing striae.The study was conducted on 30 patients.PRP and FrCO 2 laser were performed on one side of the body, PRP and PDL on the other side of the body.Treatments were performed every 6 weeks, and the total number of treatments was three.The study results showed that better results were obtained with the combination of PRP and fractional laser treatment, while skin biopsy showed improvement in epidermal thickness and uniform collagen fiber alignment in both groups, but with greater statistical significance in the case of PRP and the laser.Both methods were safe and postinflammatory hyperpigmentation (PIH) occurred in patients but was minor. 11ny et al. included 10 women with SA in their study.Three different sites on the subjects' bodies were selected.The first site was treated with PRP, the second site with CO 2 /RF laser and the third site with both methods.Three treatments were performed, with a 1-month break in between.A biopsy was performed on each woman before and after the treatment series.The research results showed that the PRP and fractional laser treatments alone caused a decrease in collagen and elastin, while the synergy of the two treatments resulted in an increase in collagen and a decrease in elastin.
These are further studies showing that the combination of at least two methods provides spectacular results in reducing striae. 26m et al. conducted a study with 19 women who suffered from striae.Each subject was treated intradermally three times a month with RF and PRP.The test results showed that none of the patients experienced worsening of striae, and only 5.3% of the patients achieved complete improvement and 36.6% showed significant improvement.At least five people showed a slight improvement after the treatment series.Nevertheless, 63.2% of the patients stated that they were satisfied with the effect of the treatment. 33

| Carboxytherapy
Carboxytherapy is a treatment in which purified carbon dioxide is injected subcutaneously into various areas of the body in a controlled manner to improve tissue circulation and skin elasticity.The use of carbon dioxide itself is not new, as this therapy was used as early as the 1930s.The first therapy was used in 1932 in Royat Spa by French doctors for people with venous insufficiency.[36][37] Hodeib et al. enrolled 20 patients with striae in their study.Each patient received one carboxytherapy treatment on the left side of the body and one PRP treatment on the right side of the body.The treatment series consisted of four sessions approximately 4 weeks apart.A skin biopsy (fibronectin staining) was performed before and after the treatment series.The treatment series showed no significant difference between treatments; however, fibronectin expression was higher in the group receiving carboxytherapy. 38her investigators decided to evaluate the efficacy and safety of fractional CO 2 laser by comparing its use with carboxytherapy.
Thirty patients who under-went fractional laser treatment on the left side and carboxytherapy on the right side participated in the study.
The treatments were performed every 4 weeks, and the number of sessions was six.The research results indicated that the fractional CO 2 laser produced better clinical and radiological improvement compared with carboxytherapy. 39morsy et al. also conducted studies with the fractional CO 2 laser and carboxytherapy.The test results showed that there was no difference between the treatments, they had a statistically significant effect on reducing striae to the same extent.No statistically significant difference was found between the treatments, proving that they are treatments with comparable effect. 40med et al. measured and compared the effectiveness of three striae treatment methods.Forty-five patients participated in the study and were divided into three groups.Group A received an injection of carbon dioxide, group B was treated with PRP, and group C used tripolar RF.The study results showed that all groups had clinical improvement in the width and texture of the striae.In this case, there were no significant differences between the groups.

FU N D I N G I N FO R M ATI O N
We received no funding for this project.

CO N FLI C T O F I NTE R E S T S TATE M E NT
All the authors declare that there is no conflict of interest.

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CON CLUS IONSToday's dermatology and cosmetology is characterized by a highly developed level of treatments.Modern treatment equipment allows us to offer help to people struggling with striae.It is no longer a skin defect that you have to live with.It is a defect that should and can be fought to achieve a better appearance of the skin and improve the quality of life.Research results show that single treatments do not provide as good results when it comes to the synergy of at least two methods.Every client's skin is different and the changes will show up in different times.Therefore, each method should be selected individually to suit the client's needs.However, these changes are best reduced by interventional methods.AUTH O R CO NTR I B UTI O N S M.R. and K.CH.performed the research.M.R. designed the research study.M.H.G. supervised the findings of this work.All authors discussed the results.M.R. and K.CH.wrote the initial draft.M.R., K.CH., M.H.G., R.S., S.W., and B.B.F.wrote the revised version.All authors contributed to the preparation of data and finalization of this article.