Q-switched Alexandrite Laser Treatment Research Articles

Use of Reflectance Confocal Microscopy to Predict Treatment Efficacy in Café Au Lait Macules.

Multiple lasers have been used for the treatment of café au lait macules (CALMs) with various results. Objective tools to predict therapeutic efficacy of CALMs treatment is lacking. To determine whether reflectance confocal microscopy (RCM) characteristics correlate with CALMs response to laser treatment. All CAMLs underwent RCM examination of length and density of dermal papillae followed by 3 sessions of Q-switched alexandrite laser (QSAL). A visual analog scale was used to assess clinical treatment efficacy. Forty-three patients were included, 22 had CALMs with irregular borders and 21 with smooth borders. Café au lait macules with irregular border had shorter rete pegs and less papillae (p < .05) on RCM compared with smooth border CAMLs and responded better to QSAL treatment (2.32 vs 1.10). Reflectance confocal microscopy measurement of length and density of papillae were inversely correlated with treatment response. Reflectance confocal microscopy may be a useful tool to predict CALMs response to laser treatment.

Comparison of a picosecond alexandrite laser versus a Q-switched alexandrite laser for the treatment of nevus of Ota: A randomized, split-lesion, controlled trial

Novel picosecond lasers have been available for various pigmentary disorders. However, there are limited data directly comparing picosecond lasers and Q-switched lasers for treatment of nevus of Ota. To compare the efficacy and safety of a picosecond alexandrite laser (PSAL) with a Q-switched alexandrite laser (QSAL) for the treatment of nevus of Ota. Each lesion of 56 enrolled participants was split into 2 parts and randomly assigned to either the PSAL or QSAL treatment arm. Each lesion was treated in up to 6 sessions in 12-week intervals. Efficacy and safety were determined using blinded visual evaluation and self-report at each follow-up visit. The PSAL arm achieved a significantly better clearance (5-point scale, PSAL 4.53 vs QSAL 4.0) with fewer sessions (PSAL 5.26 vs QSAL 5.87) and less severe pain (Visual Analog Scale, PSAL 5.61 vs QSAL 6.40). Patients were more satisfied with PSAL than QSAL (Likert scale, 4.5 vs 4.0). Occurrences of postinflammatory hyperpigmentation (PSAL 26% vs QSAL 34%) and hypopigmentation (PSAL 21% vs QSAL 47%) were also lower in PSAL than QSAL arm. Lack of objective assessments and outcome measures. PSAL demonstrated better clinical results and fewer adverse events than QSAL for the treatment of nevus of Ota.

Analysis of 28 Chinese Cases of Bilateral Nevus of Ota and Therapeutic Results With the Q-Switched Alexandrite Laser.

Nevus of Ota is a dermal melanocytic lesion that presents as bluish hyperpigmentation along the first or second branch of the trigeminal nerve. It is common in Asians. However, bilateral involvement is rare. There has been no detailed report on bilateral involvement in Chinese people. To analyze the clinical data on bilateral nevus of Ota in Chinese patients and determine the efficacy of pulsed q-switched alexandrite laser treatment. Twenty-eight cases of bilateral nevus of Ota were diagnosed by clinical appearance, and detailed clinical data were collected. A q-switched alexandrite laser was used for treatment. The incidence of bilateral nevus of Ota was 1.4% (28 of 1985). More than 3 regions were involved in most patients (96.4%), and symmetrical lesions were observed in approximately 60% of cases (17 of 28). The lesion was seen at or soon after birth in 15 patients (53.6%); two-thirds of these patients (10 of 15) had ocular or mucosal involvement. The therapeutic results were excellent or good in 17 cases; the group that received more than 3 treatments and age of starting treatment being less than 6 years had better therapeutic results. The pulsed q-switched alexandrite laser is an effective treatment, and earlier intervention with more sessions achieves better results.

A retrospective analysis of the clinical efficacies of Q-switched Alexandrite and Q-switched Nd:YAG lasers in the treatment of nevus of Ota in Korean patients

Background: While the Q-switched Alexandrite laser (QSAL) and the Q-switched neodymium: yttrium–aluminum–garnet (QSNY) laser have been widely used in treating nevus of Ota, few studies compared them.Objective: To compare the efficacies of the QSAL and the QSNY laser in the treatment of nevus of Ota in Korean patients.Methods and materials: A retrospective multicenter study was conducted in 76 patients with nevus of Ota. Thirty-one patients were treated with a QSAL (5.5–8.0 J/cm2, 4-mm spot size) and 45 patients were treated with QSNY laser (6.0–12.0 J/cm2, 2-mm spot size). Treatment outcomes were categorized into five grades and the results were compared with the relevant variables taken into account using multivariate logistic regression analysis.Results: QSAL treatment was more likely to achieve a better response compared with that with QSNY laser treatment. The odds ratio of achieving an excellent response, compared with the odds ratio of having a poor response, was 12.213-times more likely when a QSAL was used than when a QSNY laser was used (p = 0.026).Conclusion: The QSAL tends to be more efficient than the QSNY laser in the treatment of nevus of Ota in Korean patients. Further controlled, prospective comparison studies are needed.

Q‐switched alexandrite laser treatment of facial and labial lentigines associated with Peutz–Jeghers syndrome

The Q-switched alexandrite laser used at 752 nm, a wavelength well absorbed by melanin relative to other optically absorbing structures in skin, causes highly selective destruction of pigment-laden cells. In addition, the 75-nanosecond pulse duration produced by this laser approximates the thermal relaxation time for melanosomes, thereby confining the energy to the target. Facial and labial dark brown macules quickly identify patients with Peutz-Jeghers syndrome. These lentigines may be cosmetically disfiguring. The Q-switched alexandrite laser produces clinically significant fading of mucocutaneous melanosis in association with Peutz-Jeghers syndrome without complications often seen with other therapeutic modalities. To evaluate the efficacy and safety of the Q-switched alexandrite laser in treating facial and labial lentigines of Peutz-Jeghers syndrome. 43 patients diagnosed with Peutz-Jeghers syndrome were treated and studied in our laser center from 2000 to 2010. We used a Q-switched alexandrite laser specified with 75 ns pulse length, emitting at 752 nm and with a 2.4 mm-diameter spot size. The lesional skin was irradiated with fluences of 5-7 J/cm2. The treatment intervals were 3 months. After treatment with the Q-switched alexandrite laser, 55.8% (24/43) of the patients had excellent results in which more than 75% of the pigments cleared, and 44.2% (19/43) showed good results. Three sessions were required to obtain excellent results. We observed no serious complications. We obtain a successful outcome in the treatment of these lentigines with Q-switched alexandrite laser and consider it the treatment of choice for these lesions.

Effect of spot size and fluence on Q-switched alexandrite laser treatment for pigmentation in Asians: a randomized, double-blinded, split-face comparative trial

Background: Q-switched laser treatment for pigment disorders commonly leads to postinflammatory hyperpigmentation (PIH) in Asians. Objectives: To evaluate the effect of spot size and fluence on Q-switched alexandrite laser (QSAL) treatment for pigmentation in Asians. Methods: Ten patients with freckles, 18 with lentigines, and 8 with acquired bilateral nevus of Ota-like macules (ABNOM) received 1 session of QSAL treatment for a 3-mm spot on one cheek and a 4-mm spot on the other cheek. The lowest fluences to achieve a visible biologic effect were chosen. Results: The patients with freckles experienced the highest improvement rate (83–84%), followed by those with lentigines (52%) and ABNOM (35%). Similar efficacy was observed for both cheeks (p > 0.05). PIH developed in 10% (1/10), 44% (8/18), and 75% (6/8) of the patients with freckles, lentigines, and ABNOM, respectively. The severity of PIH was lower in the 4-mm spot with a lower fluence than in the 3-mm spot with a higher fluence in patients with lentigines (p = 0.03), but not in those with freckles or ABNOM. Conclusions: Using a larger spot to achieve the same biologic effect at a lower fluence is associated with equal efficacy and less-severe PIH in patients with lentigines.

Dermal Melanocytosis of the Helix

A 2-year-old Japanese boy had a congenital gray-blue macule involving the right helix along with a few melanotic spots on both sclerae. Histopathology showed dermal melanocytosis. Q-switched alexandrite laser treatment induced a good cosmetic response. This patient shows the overlap between Ota and Ito nevi, and we suggest dermal melanocytosis is better used as a generic term for these unusual pigmentations.

Q-Switched Alexandrite Laser Treatment of Oral Labial Lentigines in Chinese Subjects with Peutz-Jeghers Syndrome

Peutz-Jeghers syndrome (PJS) is characterized by gastrointestinal hamartomatous polyps and visible mucocutaneous lentigines distributed in the oral and anal mucosa, hands, face, and nails. Although there are many reports regarding successful treatment of intestinal polyps of PJS, there is little information regarding treatment of lentigines. Q-switched lasers are the preferred method of treatment for benign melanocytic lesions. To evaluate the efficacy of the Q-switched alexandrite laser (QSAL) in treating oral labial lentigines of PJS. Fourteen cases of laser treatment of oral labial lentigines in patients diagnosed with PJS were studied between 2005 and 2008. All were treated using a single treatment with a QSAL with a 3-mm handpiece and a fluence of 4.0 to 9.0 J/cm(2). Retrospective analysis of the effect of QSAL was conducted. All 14 cases exhibited successful elimination of treated lentigines after one laser treatment. There were significant acute side effects. After a median 2-year follow-up, there were no recurrences or scars in treated sites. The QSAL provides effective treatment for removal of labial lentigines associated with PJS.

Laser Treatment of 26 Japanese Patients with Mongolian Spots

BACKGROUND Mongolian spots are congenital hyperpigmented areas of varying size and shape and are usually confluent grayish-blue in color. They are found most frequently in the sacral region and typically disappear during childhood. Occasionally, they persist to adulthood. OBJECTIVE We used Q-switched alexandrite laser treatment for Mongolian spots and examined therapeutic outcomes of 26 Japanese patients who consulted our department. MATERIALS & METHODS We retrospectively compared 26 Japanese patients before and after treatment. RESULTS A good therapeutic outcome was achieved overall, but some adult female patients subsequently developed severe postinflammatory hyperpigmentation. Sacral Mongolian spots were more laser-resistant than extrasacral Mongolian spots. CONCLUSION The outcome correlated with the age of patients at the initiation of treatment; therefore, sacral and extrasacral Mongolian spots should be treated before 20 years of age. To avoid severe postinflammatory hyperpigmentation, the optimal interval between laser treatments and the use of other treatment modalities including Q-switched ruby laser, Q-switched neodymium-doped yttrium aluminium garnet laser, or bleaching creams should be considered. Our results will be of some help in considering the treatment course of patients with Mongolian spots.

Laser Treatment of 26 Japanese Patients with Mongolian Spots

Mongolian spots are congenital hyperpigmented areas of varying size and shape and are usually confluent grayish-blue in color. They are found most frequently in the sacral region and typically disappear during childhood. Occasionally, they persist to adulthood. We used Q-switched alexandrite laser treatment for Mongolian spots and examined therapeutic outcomes of 26 Japanese patients who consulted our department. We retrospectively compared 26 Japanese patients before and after treatment. A good therapeutic outcome was achieved overall, but some adult female patients subsequently developed severe postinflammatory hyperpigmentation. Sacral Mongolian spots were more laser-resistant than extrasacral Mongolian spots. The outcome correlated with the age of patients at the initiation of treatment; therefore, sacral and extrasacral Mongolian spots should be treated before 20 years of age. To avoid severe postinflammatory hyperpigmentation, the optimal interval between laser treatments and the use of other treatment modalities including Q-switched ruby laser, Q-switched neodymium-doped yttrium aluminium garnet laser, or bleaching creams should be considered. Our results will be of some help in considering the treatment course of patients with Mongolian spots.

Accentuated Varicella Eruption: A Complication of Q-Switched Alexandrite Laser Treatment

Accentuated Varicella Eruption: A Complication of Q-Switched Alexandrite Laser Treatment

Recurrent Pigmented Macules after Q-Switched Alexandrite Laser Treatment of Congenital Melanocytic Nevus

Q-switch-mode laser treatment of congenital nevi does not result in complete histological clearance, and many patients have partial repigmentation within several months. In addition, the number of recurrent pigmented macules (RPMs) may increase, a major drawback to good cosmetic results. While the mechanism of recurrence is not known. To help elucidate the mechanism of RPM development, we evaluated the expression of TNF-alpha and E-cadherin on RPM after treatment of congenital nevi with a Q-switched alexandrite laser (QSAL). Thirteen Korean subjects with congenital nevi received QSAL treatment at intervals ranging from 2 to 6 months (mean, 4.5 treatments). Two-millimeter punch biopsy specimens were obtained at their first visit and from RPMs 3-6 months after the last treatment. Expression of E-cadherin and TNF-alpha were determined histochemically in the original nevi and RPM. In addition, one RPM was examined by electron microscopy. Reduced pigmentation in the treated areas was seen in all cases, but partial repigmentaion was seen as black spots within 6 months after the last QSAL treatment. Compared to the original nevi, the RPMs had increased numbers of melanocytes in the epidermis and reduced nevomelanocytic nests in the dermis. The expression of TNF-alpha and E-cadherin was downregulated in the RPMs compared to the original nevi. Electron microscopy confirmed the increase in melanocytes in the epidermis of RPMs. Our findings suggest that the down-regulation of E-cadherin and TNF-alpha may induce the proliferation of melanocytes, resulting in the formation of RPMs.

Recurrent Pigmented Macules after Q-Switched Alexandrite Laser Treatment of Congenital Melanocytic Nevus

Recurrent Pigmented Macules after Q-Switched Alexandrite Laser Treatment of Congenital Melanocytic Nevus

Cosmetic tattoo refractive to Q-switched alexandrite laser

Lip tattooing is a common cosmetic technique not exempt from certain risks and which may lead an unsatisfied customer to seek tattoo elimination. To assess the clinical outcome of a patient with a brownish-colored cosmetic lip tattoo after treatment with the Q-switched alexandrite laser (QSAL). Two sites were tested using the pigment lesion dye laser (PLDL) and QSAL. The patient received 10 monthly sessions with QSAL, with an average fluence of 6.925 J/cm2. The double and triple shot technique was applied. The brownish pigmentation turned black after the PLDL and QSAL tests. Epidermal splattering and bleeding made a fluence increase with QSAL inadvisable. Treatment was unsuccessful. PLDL and QSAL may induce a photochemical alteration in brownish pigment. Factors that may contribute to the poor response of a cosmetic lip tattoo to QSAL treatment are related to pigment characteristics and laser parameters.

Q-switched Alexandrite laser treatment of Ota's nevus. (Japanese)

Q-switched Alexandrite laser treatment of Ota's nevus. (Japanese)

Q-switched alexandrite laser treatment (755 nm) of professional and amateur tattoos

Background: Several laser techniques have been proposed for the removal of decorative tattoos. The lasers that have been used most successfully are Q-switched red or near-infrared systems because of their ability to target tattoo pigment selectively with minimal risk of scarring or permanent pigmentary changes. Objectives: The objectives of this study were to determine the clinical effectiveness of the newest Q-switched system, the alexandrite laser, in removing amateur and professional tattoos and to observe side effects. Methods: Twenty-four multicolored professional tattoos and 18 blue-black amateur tattoos were treated with the Q-switched alexandrite laser (755 nm, 100 nsec) at 2-month intervals until total clearing was achieved. The 510 nm pulsed dye laser was used to treat tattoos that contained red pigment. Results: Professional tattoos required an average of 8.5 alexandrite laser treatments for total clearance, whereas only 4.6 treatments were necessary to remove amateur tattoos. Red tattoo pigment was successfully treated with an average of two 510 nm pulsed dye laser sessions. No scarring or long-standing pigmentary changes were seen in laser-irradiated skin. Conclusion: The Q-switched alexandrite laser is highly effective in removing multicolored professional and amateur tattoos without adverse sequelae. The 510 nm pulsed dye laser was useful in eliminating red tattoo pigment.