Innovations in pigmentation treatment and my personal experiences/preferences

Melasma is an acquired, chronic hyperpigmentation disease characterized by light-dark brown macules that appear symmetrically on the sun-exposed parts of the body, usually on the face. It is usually seen in women. It is especially more common in individuals with Fitzpatrick skin type IV-V, such as Latinos, Africans, African-Americans, and Asians. 1,2 This disorder severely affects quality of life as it creates deep psychological and social stress. Although it has been suggested that many factors play a role in the pathogenesis, the main cause is still not understood. The most common identifiable risk factors are dark Fitzpatrick skin types (especially >III), ultraviolet radiation (sun exposure), genetic predisposition, pregnancy, drugs such as oral contraceptives and antiepileptics (phototoxic). It has also been shown to be related to ovarian dysfunction, liver diseases and cosmetic reasons. Histologically, melasma is characterized by an increase in dermal and/or epidermal melanin, which is thought to be due to increased pigment production and deposition.6 In some of the studies on this subject, melanocytes and melanophages were found to be increased in biopsies; in some studies, an increase in dendritic protrusions and melanosomes was observed while the melanocyte count was stable, suggesting hyperactivity rather than hypertrophy.6 Studies also suggest that a damaged basement membrane would allow for increased melanin penetration and melanocyte projection into the dermis.7 As Kim et al. found that lesional melasma biopsy specimens had more vascular endothelial growth factor production release than the surrounding intact tissue. Post-inflammatory hyperpigmentation (PIH), which is similar to melasma, is an acquired pigmentary disorder that occurs as a result of inflammation due to various causes such as cutaneous diseases and treatment. Conditions associated with PIH include acne, folliculitis, lichen planus, herpes zoster, and eczema. It can also occur due to trauma, medication, or laser therapy. PIH occurs equally in men and women, but is more common in those with darker skin tones. The distribution of the causative dermatoses determines the PIH area. The color of the lesion varies from light brown to bluish gray and the lesion is irregularly shaped. PIH usually persists for months to years. In PIH, all these conditions damage the basal cell layer and cause melanophages to accumulate in the upper dermis, where they will remain for a while. In addition, arachidonic acid, prostaglandins, and leukotrienes released as a result of inflammation also stimulate melanocytes to produce melanin.8 Histological examination can reveal melanophages and epidermal melanin in the upper dermis. Lymphohistiocytic infiltration around the vascular structures in the dermal papillary layer also draws attention. Since melasma and PIH are not a static pigment storage period due to overproduction in a single time, but a dynamic and chronic process due to hyperactivity of cells, it is very difficult to provide permanent treatment. DRUG THERAPIES Many topical drugs have been used in the treatment of PIH and melasma. These include hydroquinone, mequinol, N-acetyl-4-S-cysteaminylphenol, kojic acid, arbutin, ascorbic acid (vitamin C), alpha tocopherol (vitamin E), niacinamide, botanical/plant extracts, grape seed extract, orchid extract, aloe vera extract, pycnogenol, seaweed extract, cinnamic acid, flavonoids, green tea extracts, aloesin, coffeeberry, mulberry extract, soy (glycine soy), licorice extract, umbelliferone, boswellia, sillymarin, N-acetyl glucosamine Creams containing substances such as retinoids and alpha hydroxy acids or their combinations are available.9,10 The mechanism of action of classical lightening creams is generally tyrosinase inhibition (hydroquinone, arbutin, licorice root, azelaic acid, kojic acid), keratinocyte from melanocytes. Inhibition of melanosome transition to cells (tretinoin, soy, niacinamide), inhibition of melanocyte secretory functions (corticosteroids), acceleration of cell cycle of keratinocytes (tretinoin, alpha hydroxy acids) and cytotoxic effect (hydroquinone, azelaic acid, arbut) of). The lack of a highly valid, safe and effective topical method in the treatment of melasma and PIH has led to the need for combination therapies from a medical point of view. Single treatment approaches are not successful in most patients, nor do they have long-lasting effects. Combination treatments usually provide optimum results. However, melasma and PIH are difficult to treat and mild to moderate improvement can be achieved in the majority of patients. Since patients with dark skin (Fitzpatrick type IV-VI) tend to develop PIH, treatment options such as laser and chemical peeling are limited. The use of topical drugs that suppress melanin production expands the treatment options by preventing the development of PIH after laser and chemical peeling. There is great demand in hyperpigmentation cosmetics. These substances target key regulatory stages in melanin synthesis. Due to the low incidence of side effects of various substances, their use in commercial preparations is increasing. The literature on their efficacy and side-effect profile is scarce. More studies are needed to evaluate their role. Longer patient follow-up and compliance are very important in any cosmetic use compared to conventional treatments. In addition, good sun protection is essential for a good result. Better results are obtained in the treatment of PIH with spot medications than melasma. In PIH, the lesion usually does not return after healing with topical drugs that stain. Although topical drugs that suppress the production of melanin in melasma cause discoloration, the stain returns after a short time when they are released. In fact, topical spot removal creams usually provide temporary suppression, not treatment. In addition, drugs containing hydroquinone and tretinoin cause erythema by causing irritation in some patients and melasma is triggered. Although there are many studies on azelaic acid, we could not practically observe a significant effect in melasmas, except for PIHs. For this reason, we prefer anti-oxidant creams that repair the skin alone or together with tyrosinase inhibitors in the treatment of melasma. Transecsamic acid, which is a plasmin inhibitor, has been found to reduce epidermal pigmentation, vascular structure, and mast cell count.11 In the treatment of hyperpigmentation, transecsamic acid has been tested with oral, topical, and mesotherapy methods.12 Lee et al. In 85 patients with melasma, they found a significant decrease in the MASI score with weekly intradermal injection of transecsamic acid into the melasma areas. 13 The use of oral transecsamic acid together with the Q-switched Nd:YAG laser increased the treatment efficacy of the laser. 14 Transecsamic acid 5% and 10% ampoule form is available in our country. Lee et al. We perform intralesional application as in the study. It is especially beneficial in PIH, but we did not see a permanent effect, even though it temporarily lightened the color of melasma. CHEMICAL PEELING Chemical peeling is the application of chemical agents to the skin that will provide controlled damage to a part of the epidermis, including or excluding the dermis. This damage allows peeling and removal of superficial lesions, followed by new epidermal and dermal tissue regeneration.15 Chemical peeling is a well-known treatment modality in the treatment of melasma and PIH. The main mechanism of action of chemical peels in the treatment of melasma is the removal of unwanted melanin from the environment by providing a controlled chemical burn on the skin. Peels have been proven to be effective agents for melasma, both alone and in combination with other topical therapies. Although there are many agents for chemical peeling, the options are quite limited when it comes to Fitzpatrick type IV and higher skin.16 This is because deep chemical peels cannot be used in patients with dark skin due to the long-term risk of hyperpigmentation. Even medium-depth peels should be used with the utmost care. ALFA HYDROXYL PEELINGS The most commonly used alpha hydroxyl peel is glycolic acid (GA). It is generally used as a 30-70% GA solution. After a test peel, serial GA is applied to the skin at intervals of 2-3 weeks and for 3-5 minutes. Then the peel is cleaned with water or 1% bicarbonate solution. Most studies on the use of GA on dark skin have moderate improvement in about half of the patients.17 As expected, the epidermal type is the best responsive, followed by the mixed type. The dermal type is almost resistant to chemical peels. Lactic acid, which is also an alpha hydroxyl acid, acts through the same mechanism as GA. Although this agent is inexpensive and easy to access, it is not widely used in the treatment of melasma. ALFA KETO PEELLER One of the members of this group is pyruvic acid, which has gained importance in recent years. The reason for this interest is that besides stimulating new collagen and elastic fiber formation, it also has various keratolytic, antimicrobial and sebostatic properties. This agent, which is effective in acne, sun damage and superficial scars, has also been effective in some pigmentary disorders in light-skinned patients.18 However, the intense burning sensation due to pyruvic acid limits its use as a peeling agent. Also, since most studies have been done on Fitzpatrick type II-IV skins, it is difficult to predict the effect of the same condition on dark skin. BETA HYDROXYL PEELS Salicylic acid, a beta hydroxyl peel, is widely used in acne, and has also been tested for pigmentary disorders such as melasma and PIH. In fact, ethanol solutions of salicylic acid are excellent peels in the treatment of many conditions such as acne, melasma and PIH in patients with dark skin. The mechanism of action of salicylic acid in reducing pigmentation is slightly different from GA peels. Salicylic acid is an anti-inflammatory, therefore it reduces the risk of PID that may occur following the use of exfoliating agents on the skin. Grimes et al. in a study of dark-skinned patients used 20-30% salicylic acid peels for the treatment of acne, PID, and melasma, and found moderate improvement in almost two-thirds of patients with melasma. Mild side effects regressed. However, it is difficult to say that this method is better than glycolic peels unless comparative studies are conducted. Recently, lipohydroxyacid, a salicylic acid derivative with an additional fatty chain, has come into use.19 Thus, since the lipophilicity of salicylic acid has been increased, its area of ​​action has expanded and its keratolytic effect has increased. This agent also modifies the stratum corneum to be thinner, more flexible, and more resistant to cracking and wrinkling. Although beneficial effects have been observed in patients with acne, it is not yet known whether it is more effective and safe for melasma than salicylic peels. SALICYLIC MANDELIC ACID PEELINGS This combination between an alpha hydroxyl acid and a beta hydroxyl acid has not yet been fully tested as a peeling agent. Mandelic acid, one of the largest alpha hydroxyl acids, enters the epidermis slowly and regularly, making it the ideal exfoliating agent for sensitive skin.20 Salicylic acid, on the other hand, has rapid skin penetration and has a significant contribution to reducing the risk of PIH. In this context, the combination of these two agents can be effective, especially in dark skin. Although there are no published studies for melasma, salicylic mandelic peels (SMP) have shown that they are more effective than GA peels with their effects on acne and post-acne scars.21 In addition, the rate of side effects is less in SPMs. TRICHLOROACETIC ACID PEELS Trichloroacetic acid (TCA) peels, which are widely used in light skin tones, are not preferred for dark skins due to the risk of scarring and dyschromia. This is probably due to the overtreatment of dark skin treatments with TCA peels, caused by not knowing the exact point at which the treatment should be discontinued. Low doses of TCA (10-35%) are preferred in the treatment, and these doses can reach the upper papillary dermis. Therefore, it is not very suitable for use in the treatment of dermal or mixed melasmas. JESSNER SOLUTION The combination of resorcin, salicylic acid and ethanolic lactic acid is used as a superior peeling agent on all skin types. Jessner’s solution, which is a medium-depth peel, has recently attracted attention again thanks to its combination with agents such as GA and TCA. TRETHINOIN PEELINGS Although topical tretinoin has intensive clinical use in the treatment of melasma, both alone and as a component of the Kligman formula, the number of publications on the peel form, which also shows good results, is very few. The mechanism of action of tretinoin peels depends on the changes in the distribution of epidermis and melanin in the same way as topical tretinoin. NEW PEELINGS Despite the continuing popularity of exfoliating agents in use, new agents have begun to be developed in a group of pigmentary dyschromia including melasma. One of the most important obstacles to the application of alpha hydroxyls is the need for neutralization and the difficulty of estimating the duration of this neutralization. If the peel is neutralized early, it cannot show sufficient effect; In addition, if neutralization is delayed, side effects may occur. The simple solution to this problem is phytic peel. It is an alpha hydroxyl peel with a low pH and does not require neutralization, which means that excessive peeling is avoided.22 The peel works progressively and sequentially due to its acid and non-aggressive nature. In this way, the burning sensation typical of glycolic peels does not occur in phytic acid peels. This peel solution can stay on the face until the next morning, unlike alpha hydroxyl peels, which need to be cleaned quickly after neutralization. Phytic acid solutions are usually applied once a week, but can be used twice a week when a more intense effect is required. 5-6 sessions are required for the effect to be seen. Although there are not many publications on this subject, it is of course necessary to conduct more studies on this subject. Another agent is Obagi blue peel. This is a combination of a fixed concentration of TCA with the blue peel root (containing glycerine, saponins and non-ionic blue color root). The mixture provides a decrease in the surface tension of TCA, water and glycerin, resulting in slower and more regular TCA penetration.23 One of the latest additions to chemical peels is amino fruit acid peels. There are potent antioxidants with anti-aging cosmetic and anti-photopigmentation effects. According to a recent study conducted on patients with light skin, amino fruit acid peels were found to be as effective as GA peels and more easily tolerated.24 However, there are no studies conducted with patients with dark skin on this subject. LASER-IPL Lasers are used with varying success rates in the treatment of many pigment-related disorders such as Becker nevus, cafe-au-lait spots, nevus of Ota, nevocellular nevus, lentigo, tattoos, melasma, and post-inflammatory hyperpigmentation (PIH). Most pigmentary disorders respond well to laser therapy, but their efficacy and safety in the treatment of melasma and PIH are still controversial. Lasers (Light Amplification by Stimulated Emission of the Radiation) are high-intensity monochromatic coherent beam sources. They can be used in the treatment of many different dermatological conditions, which vary according to wavelength, beam characteristics, penetration, and the nature of the lesion being treated. In addition, IPL, a high-intensity incoherent multichromatic beam, can be used in similar situations. If energy is sent to the target pigmented cell for a shorter time than the thermal relaxation time, this energy is limited to the target and less damage is done to the surrounding tissue. should be kept high. If the target melanin is selective range between 630 and 1100 nm, skin penetration is good in this range, and melanin has superiority over oxyhemoglobin in terms of selective absorption.26 Melanin absorption decreases with longer wavelength, but longer wavelength means better skin penetration. Shorter wavelengths (<600 nm) damage pigmented cells with a low energy current, while longer wavelengths (>600 nm) penetrate deeper but require more energy to damage melanosomes. Q-SSWITCHED ND:YAG LASER 1064nm Q-Switched (QS) Nd:YAG laser is absorbed by melanin, thanks to its long wavelength, deep skin penetration makes it effective in the treatment of dermal melanin. Exposure to low-dose QS Nd:YAG rays causes non-fatal damage to melanosomes and ruptures melanin particles into the cytoplasm.25 Since this wavelength is absorbed by melanosomes more than any other structure, this effect has a high selectivity for melanosomes. In patients with melasma, the dendrites of melanocytes are increased in the melasma area compared to normal skin. Low-dose QS Nd:YAG reduces dendrites in melanocytes in the epidermis. In addition, the upper dermal vascular plexus, which is one of the pathogenetic factors in melasma, is damaged. Sub-threshold damage to the surrounding dermis also stimulates collagen formation, resulting in a brighter and tighter skin. QS Nd:YAG is the most widely used laser in the treatment of melasma and PIH. The spot size is 6-8mm, the frequency is 10Hz, and the energy is less than 3J/cm2. The number of treatment sessions varies between 5-10 at 1-3 week intervals. It is recommended to avoid too many sessions (>10) or too high energy (>3 J/cm2) QS Nd:YAG laser sessions in order to prevent the side effects of guttate hypomelanosis. Hypopigmentation should be evaluated at each session and treatment should be terminated if present. QS Nd:YAG laser is the most commonly used method in the treatment of melasma. We apply the QS Nd:YAG laser with 3-6 sessions of PRP in the same session and in between. When we apply QS Nd:YAG laser alone, the lightening rate of the spots is low and the recurrence is high. After QS Nd:YAG laser applied with PRP, the recovery rate of melasma is high and the recurrence rate is low. ERBIUM:YAG LASER Erbium:YAG (Erbium:Yttrium-Aluminum-Garnet) lasers emit radiation at a wavelength of 2940 nm, which is highly absorbed by water. In this way, they ablate with minimal thermal damage to the skin. The occurrence of PIH limits the use of this laser in intractable melasma. Moreover, the number of studies on this subject is extremely limited. Combinations of ablative and pigment-selective lasers have also been tried in the treatment of melasma. In resistant melasma, there is abnormal pigmentation in both the epidermis and dermis. The part of the epidermis that contains excess melanin and abnormal melanocytes is treated with ablative lasers. Following this, treatment can be continued with Q-switched pigment lasers, which can reach dermal melanophages, which are deeper lesions in the dermis, without causing significant side effects. We use Ablative Erbium:YAG laser in the treatment of melasma in patients with skin type II in 12 mm spot, 10 hertz, 1- 1.2 J/cm2 300 µs mode. In most patients, it is effective in lightening the color of melasma and increasing the quality of the skin. However, PIH can develop. The PIH reaction is regressed with QS Nd:YAG laser within one month in fair-skinned people. We do not prefer this method in patients with skin type IV and V, as PIH side effects may be permanent. PULSE DYE LASER (PULSED DYE LASER) The use of pulsed dye laser (PDL) in the treatment of melasma and PIH is based on the theory that skin vascularization plays an important role in the pathogenesis of melasma. Melanocytes express vascular endothelial growth factor receptors 1 and 2, which are involved in the pigmentation process. PDL, whose main area of ​​use is vascular lesions, reduces melanocyte stimulation and subsequent relapses by targeting the vascular component of melasma. Based on our observation, which is also supported by publications, we apply two sessions of PDL laser 595 nm at the beginning and middle of their treatment to patients with intense telangiectasia on their skin.27 Adding this treatment reduced the likelihood of melasma recurrence and PIH in patients with a tendency to flushing and with a high rate of PIH. FRACTIONAL LASERS Fractional photothermolysis is a new concept in laser therapy as a method in which most of the intact skin is preserved by creating multiple microscopic areas of thermal damage. Protected skin acts as a reservoir for healing. Fractional laser therapy has many advantages. This technique does not create open wounds. The stratum corneum was observed as intact 24 hours after the treatment. In this way, healing is accelerated and complications related to open wounds such as hyper/hypopigmentation are prevented. Moreover, since the entire skin surface is not ablated, enormous depths can be reached, which means a chance to be used in the treatment of dermal melasma and PIH. Although PIH is more common following ablative laser therapy, it may also occur as a complication of fractional photothermolysis. According to one study, this rate is 0.73% after fractional photothermolysis. 28 This risk is reduced by lowering the treatment densities and using cooling devices during the laser. 29 Fractional erbium 2940 nm and fractional carbon dioxide (CO2) laser melasma treatment with QS Nd: We used it in combination with YAG laser. Applying the combined treatment contributed to the acceleration of the lightening of the spots. However, the unexpected development of PIH during treatment prevented us from using these lasers. None of the PIHs that occurred were permanent and although they regressed in 2-3 sessions with the QS Nd:YAG laser, the patient’s compliance with the treatment deteriorated. Therefore, we can only use erbium fractional laser infrequently in patients with skin types I and II. INTENSIVE PULSE BEAM THERAPY – INTENSE PULSE LIGHT IPL was developed in the late 1990’s and is based on the logic of broad spectrum (500-1200nm), non-coherent non-parallelized beam propagation with xenon-chloride lamp. The advantage of IPL lies in the flexibility of its parameters. The wavelength, current, number, duration, and beam delay can be varied according to the patient so that the chromophores can be targeted effectively. This advantage allows this method to be used in many different situations such as vascular lesions, epilation and melanocytic lesions. However, there are few studies focusing on the use of IPL in the treatment of melasma. Although successful treatments have been reported in melasma with IPL, the recurrence rate is high. After melasma is treated with IPL, melasma is opened. However, after 2 weeks, the stain returns in 3-4 weeks as the melanosomes are filled with melanin again and the melanocytes are activated. Therefore, it is recommended to apply low-dose QS Nd:YAG laser 2 weeks after IPL application, and to apply 4 sessions with one-week intervals. In the study, 60% of the patients did not need additional treatment after the treatment.30 We apply this protocol with a long pulse alexandirite laser in patients with skin type IV, very dark spots, and small areas. We use IPL in other patients. PRP PRP (Platelet Rich Plasma); The plasma fraction of autologous blood containing an above-normal platelet concentration. They act as a growth factor complex agonist. It shows both mitogenic and chemotactic properties. 7 growth factors with proven effects in wound healing are secreted by platelets. These; PDGF alpha-alpha, PDGF alpha-beta, PDGF beta-beta, TGF beta 1, TGF beta 2, vascular endothelial growth factor, epidermal growth factor. In addition, TGF beta 1 has an inhibitory feature of melanogenesis.31 In PRP, there is PDGF at a concentration 30 times higher, EGF at a concentration 10 times higher, and TGF beta at a concentration 7 times higher than in whole blood. These growth factors released from PRP act by binding to their receptors in mesenchymal stem cells, fibroblasts, osteoblasts, endothelial cells, and epidermal cells. 32-35 PRP stimulates the body’s own cells to regenerate and restructure tissues, and reshapes collagen fibers. softens folds and lines. In dermatology; It is applied in the treatment of androgenetic alopecia, in skin rejuvenation, in the treatment of fine lines and wrinkles, for filling purposes or as a complementary treatment in addition to many cosmetic applications. Normally, after blood coagulation, α-granules migrate to the platelet surface within 10 minutes and secrete the growth factors in their contents, and 95% of them are secreted in the first hour. Therefore, this feature should be taken into account during the procedure and the prepared PRP should be applied within the first 10 minutes. Studies have found a dose-response relationship between platelet concentration in PRP and mesenchymal stem cell proliferation and differentiation. It has been determined that the most ideal wound healing is achieved when PRP contains at least 4-5 times more platelets than the platelet concentration in normal blood. Therapeutic PRP used for rejuvenation should contain at least 1 million platelets. 32-35 It should be applied to the treatment area by intradermal injection and napping technique. We applied PRP for the first time to a patient who developed very dark PIH after ablative laser application for therapeutic purposes. After applying PDL, QS Nd:YAG laser and PRP together for 2 sessions, the patient’s PIH complaint regressed by 85%. After the third session, he had no complaints. In addition, we observed the lightening and lightening of the skin of the patients who underwent PRP. Therefore, we started to routinely apply PRP to melasma treatments. With the combination of PRP and laser, a better rate of lightening of the spots and a decrease in recurrences occurred. The patient seen in Picture 1 had melasma complaints for many years. There was no response to the spot-lightening cream and peeling treatments. PDL, Qswitch Nd:YAG laser and PRP were applied in the same session for melasma. Starting from the first session, a dramatic opening occurred in the spots. After three sessions, there was a 90% reduction in the spots. LENTIGO AND EPHELID TREATMENT Solar lentigo is histologically hyperpigmented basal cell layer as the number of melanocytes increases. Nesting formation is not observed in melanocytes along the basement membrane. Epidermal rete ridges are elongated. Epidermal hypermelanosis is present in ephelids without an increase in the number of melanocytes. Compared to cryotherapy and 40% trichloroacetic acid (TCA) in the treatment of solar lentigo, cryotherapy was found to be more effective, but with a higher PIH rate and a longer recovery time.36 Melanin absorbs a wide range of wavelengths (351-1064 nm). Lasers used in the treatment of lentigo and efflux are Q-switched (QS) lasers, long pulsed alexandrite 755 nm laser, long pulsed Nd:YAG 532 nm laser, long-pulse pulsed dye laser (LPDL) and IPL. QS lasers are preferred in the treatment of lentigo, especially in fair-skinned people. However, QS 532- nm Nd:YAG lasers, QS alexandirite laser (755 nm) and QS ruby ​​laser (694 nm) carry the risk of PIH in dark-skinned people. 37-39 QS Nd:YAG 532 nm with long pulsed Nd:YAG 532 nm face Compared to the lentigo, the improvement rates were found to be high in the same PIH laser. The photomechanical effect causes inflammation in the superficial vessels by damaging oxyhemoglobin, activating melanocytes, and PIH occurs. Compared with QS alexandirite laser and IPL in the treatment of lentigo and freckles, the rate of PIH was found to be higher in the QS laser.37 The long pulse alexandirite laser 755 nm was found to be effective in the treatment of solar lentigo, especially in dark lentigo. Especially in those with skin type IV and above, it has benefited without PIH and scarring.41,42 The long-pulse pulsed dye laser (LPDL) targets melanin as well as hemoglobin at a wavelength of 595-nm. For this reason, it has been used in the treatment of lentigo. It is done with diascopy to reduce the risk of PIH due to bruising. When the veins are pressed with glass, the veins are emptied and thus the possibility of vascular damage is reduced. In a study conducted with LPDL and IPL, skin regeneration effects were found to be the same in regeneration treatment, but LPDL was found to be more effective in the treatment of lentigo.43 IPL systems were found to be effective in the treatment of lentigo. PIH and scarring were not observed in IPL treatments with longer sessions than lasers.44,45 We prefer QS Nd:YAG 532 nm laser in lentigo treatments for skin types I and II with light-colored lentigo. Deri tipi III olanların QS lazer uygulamalarında PIH oranı yüksek olduğu için, koyu ya da açık lentigolarda IPL kullanıyoruz. Bazı hastalarda kalın yapıda lentigo var ise IPL ve QS Nd:YAG 532 nm laser yeterli derinliğe inemeyebi- liyor. Bu sebeple bu hastalara erbium lazer (2940 nm) ile ablasyon yapıyoruz. Bu hastaların çoğunda uzun süren eritem ve sonrasında PIH olabiliyor. Sa- dece 55 yaş üzeri hastalarda PIH görmüyoruz. Bu yaş gurubuna erbium lazeri uygulayıp, eritemli dö- nemde IPL veya PDL birkaç seans uyguluyoruz. Deri tipi IV olanlarda ve siyaha yakın koyu renkli lentigosu olanlarda ise long pulsed alexandirite lazer kullanıyoruz. Deri tipi IV ve V olanlarda, lentigoları açık renkli olduğu için alexandirite lazer etkili ol- muyorsa, diğer uygulamaların yüksek PIH olasılığı nedeniyle tedavi önermiyoruz. Lentigolu hastalarda seans sayısını öngörmek zor oluyor. Bazı lentigolar tedaviyle hemen geriliyor, bazılarında tedavi uzun sürüyor veya tekrar ediyor. Bunun bir sebebi len- tigo olarak tedavi ettiğimiz oluşumların aslında len- tigoya benzeyen başka hastalıklar (seboreik keratoz, pigmente aktinik keratoz, lentigo maligna) ol- masından kaynaklanabilir. Dermaskopla incelemek tedavi sonuçlarını düzeltebilir.46 Resim 2’de sırtında yaygın solar lentigoları olan hastaya iki seans QS Nd:YAG 532 nm lazer uygu- landıktan sonra lekeler büyük oranda kayboldu.