Treatment of Horiʼs Nevus with the Q-Switched Nd:YAG Laser

Polnikorn, Niwat; Tanrattanakorn, Somsak; Goldberg, David J.

doi:10.1046/j.1524-4725.2000.99305.x

Cited by 99 publications

(92 citation statements)

References 20 publications

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“…Although there are reports of treatment responses in melasma to IPLs and lasers, the overall benefit is often limited and of short duration [11]. Hori's macules, or ABNOM, have also been reported to variably respond to different lasers including QSRL [12], Q-switched Nd:YAG [13,14], Q-switched Alexandrite [2] and combination CO2 laser/QSRL [15]. Variability in response between studies, including ours, may be due to several factors.…”

Section: Discussionmentioning

confidence: 66%

Combined use of intense pulsed light and Q‐switched ruby laser for complex dyspigmentation among asian patients

Park¹,

Tsao²

2008

Lasers Surg Med

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Background: Dyspigmentation is a common cosmetic concern among Asians. Many individuals exhibit mixed pigmentary entities including melasma, flat/small seborrheic keratoses, ephelides, solar lentigines and acquired bilateral nevus-of-Ota-like macules (ABNOM). We term this phenomenon complex dyspigmentation (CD) and suggest that a combination strategy may be more efficacious than any singular modality. Objective: To determine the effectiveness of combined intense-pulsed light (IPL) for global photorejuvenation along with Q-switched ruby laser (QSRL) for targeted pigment dissolution. Study Design/Materials and Methods: Twenty-five Korean women with CD (defined as > 2 types of facial pigmentary disorders) were initially treated with IPL followed by repeat treatments every 3-4 weeks as needed. The QSRL treatments, set at low fluence, were added either during the same session or within 1 week of the IPL treatment. Improvement was assessed by the patient, the treating physician and a blinded evaluation of pre-and post-treatment photographs. Results: Using a 4-point scale (1 ¼ poor, 2 ¼ fair, 3 ¼ good, 4 ¼ excellent), 19/25 patients (76%) reporting good-to-excellent response (score ''3'' or ''4''). Two independent physician assessment revealed that 15/25 patients (60%) showed 76-100% improvement while 19/25 patients (76%) showed at least 50% improvement. Side-effects were minimal: 3 patients had transient post-inflammatory hyperpigmentation (12%) and 1 patient (4%) had linear hypopigmentation. Conclusions: Combination treatment with IPL and QSRL is an effective and safe treatment for CD among Asian patients.

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Section: Discussionmentioning

confidence: 66%

Combined use of intense pulsed light and Q‐switched ruby laser for complex dyspigmentation among asian patients

Park¹,

Tsao²

2008

Lasers Surg Med

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“…Therefore, QS lasers are the main treatment modalities for ABNOM as well as for nevus of Ota. In a previous report, of patients undergoing 2∼7 QSNYL treatment sessions at intervals of 2 to 6 months, 30∼100% showed a greater than 50% lightening response and the incidence of PLH ranged from 50∼100%, with differences in clinical responses due to differences in laser parameters and treatments intervals [9][10][11] . In our study, 66% of treated patients and 76% of patients who were treated more than three times showed greater than 50% of clearing and only 40% had transient PLH.…”

Section: Discussionmentioning

confidence: 99%

Q-Switched Nd:YAG Laser Therapy of Acquired Bilateral Nevus of Ota-like Macules

et al. 2009

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Background: Acquired bilateral nevus of Ota-like macules (ABNOM) is a dermal pigmented lesion common in individuals of Oriental origin. The Q-switched Nd:YAG laser (QSNYL) has been used successfully to treat a variety of benign, dermal, pigmented lesions, including nevus of Ota lesions. The similarity between ABNOM and nevus of Ota suggested that QSNYL may also be effective in the former. Objective: To determine the efficacy and side-effect profiles of QSNYL treatment of ABNOM in Korean patients. Methods: Of 42 Korean patients with ABNOM, 29 were treated with QSNYL (1,064 nm, 3 mm spot size, fluence 8∼ 9.5 J/cm 2 ), for up to 10 sessions each. Clinical photographs were taken before and after treatment. Lesion clearance was graded and complications such as hyperpigmentation, scarring, hypopigmentation, and erythema were assessed. Results: Of the 29 treated patients, 19 (66%) showed excellent or good results. Of the patients who were treated more than 3 times, 76% showed good to excellent results. Two patients experienced post-laser hyperpigmentation (PLH), which persisted for more than one month, but no patient experienced persistent erythema or hypertrophic scarring. Conclusion: QSNYL is safe and effective in the treatment of ABNOM in Korean patients. Short-interval repetitive treatment is especially useful in improving therapeutic results and reducing PLH.

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“…Only patients with SPT II or III with focal epidermal hyperpigmentation e.g. solar lentigines had mild to moderate reduction in hyperpigmentation of lesions after multiple IPL treatment [19][20][21].…”

Section: Pathogenesismentioning

confidence: 97%

New Approach for Laser Treatment of Melasma and Hyperpigmented Lesions

Polnikorn¹

2014

Pigmentary Disorders

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Melanin SynthesisMost of melasma patients are photo skin type III to V. These skin type's response to sunlight by increasing of melanin synthesis. Melasma relates to strong sun light exposure and high estrogens. Melanins are synthesized in epidermal melanocytes and transfer to epidermal keratinocytes. One melanocyte supplies thirty six keratinocytes and is called "epidermal melanin unit". Majority of melanin granules are distributed in the keratinocytes. Melanin granules in melanocytes are mainly early stage (stages I-II) which contains less melanin. UV exposure stimulates keratinocytes to release cytokines (especially endothelins) which bind to endothelin receptors on melanocyte cell membrane. The binding of keratinocytes and melanocytes is through binding of Stem Cell Factor (SCF) on keratinocytes and C-kit protein on melanocytes. Endothelins together with Melanocyte Stimulating Hormone (MSH) stimulate tyrosinase enzymes synthesis. These enzymes are essential for melanin synthesis. Any conditions producing basement membrane injuries will lead to melanin dropping down into upper dermis .They will be engulfed by macrophages transforming to what we call "melanophages". These melanophages will persist in dermis for many years. Recently, there were many published articles on finding of increase of vascular dilatation and vascular growth factor in melasma.In normal skin most of the mature melanins (stage V) will be in keratinocytes Epidermal or follicular melanocytes contain unmelanized melanin (stage I-II). This unmelanized melanin will not absorb enough laser energy to produce "Selective Photothermolysis" or photomechanical destruction of melanin and also of melanocytes. The surviving memalnocytes are the major source of recurrence of lesions after selective pigmented laser treatment (e.g. 532 nm frequencydoubled Q-switched Nd: YAG laser). For hyperpigmented lesions, mature melanin present in all these locations; keratinocytes, epidermal melanocytes and melanophages. In order to reduce hyperpigmentation, the treatment should be able to reduce melanin all three locations. In hyperpigmented lesions melanin granules also aggregate into clumps. This produces dark color, while small fragmented and dispersed melanin produce lighter colour [1][2][3][4][5][6].In summation, the following mechanisms had been used with mild to moderate result for treatment of melasma: 1.Superficial peelings e.g. chemical peels, microdermabrasion, laser resurfacing. 2.Stimulation of keratinocytes turnover. Example: vitamin A acid, glycolic acid, salicylic acid. 3.Suppression of melanin synthesis. Example: hydroquinone, arbutin, kojic acid, licorice PT40, tranxemic acid etc. 4.Reduction of pigment transfer from melanocytes to keratinocytes. Example: Niacinamide, Clove extracts 5.Destruction of melanin's containing cells (melanocytes and Keratinocytes) e.g. Q-switched laser, Fractional laser PathogenesisMelasma is a complex disease. The pathogenesis involves: 1) Hyperfunction of clones of epidermal and follicular melanocytes in certain sun-expo...

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Treatment of Horiʼs Nevus with the Q-Switched Nd:YAG Laser

Abstract: The Q-switched Nd:YAG laser can be used to treat Hori's nevus. Results are not as good as those seen with nevus of Ota.

Cited by 99 publications

References 20 publications

Combined use of intense pulsed light and Q‐switched ruby laser for complex dyspigmentation among asian patients

Combined use of intense pulsed light and Q‐switched ruby laser for complex dyspigmentation among asian patients

Q-Switched Nd:YAG Laser Therapy of Acquired Bilateral Nevus of Ota-like Macules

New Approach for Laser Treatment of Melasma and Hyperpigmented Lesions

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