Wavelength-dependent threshold fluences for melanosome disruption to evaluate the treatment of pigmented lesions with 532-, 730-, 755-, 785-, and 1064-nm picosecond lasers.

BACKGROUND AND OBJECTIVES: A threshold fluence for melanosome disruption has the potential to provide a robust numerical indicator for establishing clinical endpoints for pigmented lesion treatment using a picosecond laser. Although the thresholds for a 755-nm picosecond laser were previously reported, the wavelength dependence has not been investigated. In this study, wavelength-dependent threshold fluences for melanosome disruption were determined. Using a mathematical model based on the thresholds, irradiation parameters for 532-, 730-, 755-, 785-, and 1064-nm picosecond laser treatments were evaluated quantitatively. STUDY DESIGN/MATERIALS AND METHODS: A suspension of melanosomes extracted from porcine eyes was irradiated using picosecond lasers with varying fluence. The mean particle size of the irradiated melanosomes was measured by dynamic light scattering, and their disruption was observed by scanning electron microscopy to determine the disruption thresholds. A mathematical model was developed, combined with the threshold obtained and Monte Carlo light transport to calculate irradiation parameters required to disrupt melanosomes within the skin tissue. RESULTS: The threshold fluences were determined to be 0.95, 2.25, 2.75, and 6.50 J/cm² for 532-, 730-, 785-, and 1064-nm picosecond lasers, respectively. The numerical results quantitatively revealed the relationship between irradiation wavelength, incident fluence, and spot size required to disrupt melanosomes distributed at different depths in the skin tissue. The calculated irradiation parameters were consistent with clinical parameters that showed high efficacy with a low incidence of complications. CONCLUSION: The wavelength-dependent thresholds for melanosome disruption were determined. The results of the evaluation of irradiation parameters from the threshold-based analysis provided numerical indicators for setting the clinical endpoints for 532-, 730-, 755-, 785-, and 1064-nm picosecond lasers.

Efficacy and safety of picosecond 755-nm alexandrite laser with diffractive lens array for non-ablative rejuvenation in Chinese skin.

BACKGROUND AND OBJECTIVES: The picosecond alexandrite laser with diffractive lens array (DLA) offers the dual advantages of a picosecond pulse duration and the fractionated delivery of laser energy. This study explores the efficacy and safety of the DLA for treatment of multiple aesthetic concerns associated with photoaging of the face including skin texture irregularities, dyspigmentation, enlarged pore size, rhytides, and skin laxity. METHODS: This prospective, evaluator-blinded trial enrolled Fitzpatrick skin type III-IV patients with mild to moderate signs of facial photoaging. Patients received six full face treatments at 4 week intervals for a total of 107 treatments. Standardized photography was obtained at baseline and at 1, 2, and 3 month follow-up visits. Two independent blinded evaluators rated each of the five signs of photoaging on a 10-point visual analog scale (VAS) at each follow-up visit compared to baseline. A global aesthetic improvement score was also assigned at each follow-up visit. Secondary outcomes included patient-rated pain and heat sensation on a 10-point VAS, and overall satisfaction. Adverse events were noted after each treatment and at each follow-up visit. RESULTS: A total of 18 Chinese patients age 35-59 completed the study. A statistically significant improvement in skin texture and dyspigmentation scores was noted at the 1 month follow-up that was sustained at 3 months. No significant improvements wer--e observed in pore size, rhytides, or skin laxity. The mean pain score was 5.1 ± 2 and mean heat sensation was 3.6 ± 2.1. Expected transient erythema and edema occurred in 95.3% (102/107) and 1.9% (2/108) of treatments, respectively, and resolved in hours. No incidences of post-inflammatory hyperpigmentation (PIH) were noted at the 1, 2, and 3 month visits. CONCLUSION: The 755-nm picosecond laser with DLA is a safe and effective non-ablative modality for targeting facial skin texture irregularities and dyspigmentation in Chinese skin. Patients tolerated the treatment well with adverse effects limited to transient erythema and edema. Lasers Surg. Med. 51:8-13, 2019. © 2018 Wiley Periodicals, Inc.

A Prospective Study in the Treatment of Lentigines in Asian Skin Using 532 nm Picosecond Nd:YAG Laser.

BACKGROUND AND OBJECTIVE: To evaluate safety and efficacy of treatment with the picosecond Nd:YAG 532 nm for lentigines in Asian skin. STUDY DESIGN/MATERIALS AND METHODS: This was a prospective, open-label cohort study, using a novel picosecond 532-nm laser for the treatment of facial lentigines. Subjects received up to three laser treatments every 4-6 weeks and were assessed at 4 and 12 weeks after final treatment. Primary endpoint was degree of improvement in lentigines at 12 weeks after the final treatment, assessed by treating investigator based on Physicians Global Assessment. Secondary end-points included degree of improvement in lentigines at 12 weeks after final treatment, assessed by subject (Subject's Global Assessment), and change in mean relative Melanin index (MI) value at 3 months after final treatment as compared to baseline as assessed by mexameter measurement. RESULTS: A total of 20 patients (3 male, and 17 female) of Asian-descent with Fitzpatrick skin type III and IV, with lentigines on the face were included in this study. A total of 89 lesions were treated with the laser setting of 532-nm, 750 picoseconds, fluence of 0.2-0.5 J/cm 2 , and spot size of 4 mm. One hundred and thirty-seven treatment sessions were given in total. Eighteen patients (90%) achieved a moderate to significant improvement at 12-week follow-up based on a 5-grade physician global assessment scale. The improvement rate of relative MI (MI in the lesion minus normal skin) was 33.30 ± 18.71 and 37.63 ± 19.25% at 4- and 12-week follow-up. Post-inflammatory hyperpigmentation (PIH) occurred in 14 of 137 sessions (10.2%), and hypopigmentation occurred in one patient with five lesions (3.6%). CONCLUSION: This study demonstrates that using picosecond Nd:YAG laser 532 nm for removal of solar lentigines in darker skin type appears to be safe and effective. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc. LIMITATIONS: Small study group.

A Unique Pattern of Staphylococcal Scalded Skin Syndrome-Like Erosions in Patients with Atopic Dermatitis: Dermatitis flammeus.

We describe the clinical features of a novel complication in patients with atopic dermatitis (AD). Twenty patients, mean age 23 years, with AD who presented with staphylococcal scalded skin syndrome (SSSS)-like lesions were included between January 2008 and September 2010. Skin lesions followed a triphasic progression pattern from erythema to hyperpigmentation and then erosions. A symmetric and predominant flexural involvement was observed. Pseudomonas aeruginosa (PA) (38.9%) and Staphylococcus epidermidis (38.9%) were the most frequently cultured bacteria from skin swabs. Complete resolution was evident in all cases, and the recurrence rate was 35%. In conclusion, a unique complication characterized by triphasic progression to painful erosions was found in a cluster of AD patients. We propose the new term "dermatitis flammeus" to describe this phenomenon, with PA being one of the etiologies.

Fractional resurfacing in the Asian patient: Current state of the art.

BACKGROUND AND OBJECTIVE: Fractionated photothermolysis (FP) has revolutionized modern laser technology. By creating selective columns of microthermal damage, fractionated devices allows for greater treatment depths to be achieved without the prolonged downtime and risk of complications seen in traditional fully ablative laser resurfacing. Fractional resurfacing is a proven method to treat a variety of cutaneous conditions. In the Caucasian patient, a wide range of devices and treatment settings can be utilized safely and effectively. However, ethnic skin requires special consideration due to its unique pigmentary characteristics and clinical presentations. In this review article, we detail the current indications and strategies to optimize results and mitigate complications when utilizing fractional resurfacing for the Asian patient. METHODS: A review of the MEDLINE English literature was conducted on fractionated laser devices studied in the Asian population. Articles included describe non-ablative devices including fractionated erbium glass, thulium fiber, diode, and radiofrequency devices; and ablative devices including fractionated carbon dioxide (CO2 ) laser, erbium yttrium aluminum garnet and yttrium scandium gallium garnet (YSGG) laser. These data were integrated with the expert opinion of the authors. CONCLUSION: Taking into account the unique characteristics and cosmetic concerns of the Asian population, fractional resurfacing can be considered a safe and effective option for the treatment of atrophic and hypertrophic scarring, and photorejuvenation in ethnic skin types. Select cases of melasma may be treated with fractionated non-ablative devices, but utilized with caution. The predominant complication associated with fractional resurfacing for these conditions is post-inflammatory hyperpigmentation (PIH) and rebound worsening of melasma. A greater number of treatments at lower density settings and wider treatment intervals typically produce the lowest risks of PIH without compromising treatment efficacy. Lasers Surg. Med. 49:45-59, 2017. © 2016 Wiley Periodicals, Inc.

A retrospective analysis on the management of pigmented lesions using a picosecond 755-nm alexandrite laser in Asians.

BACKGROUND AND OBJECTIVES: Photo-aging in Chinese often presents with benign pigmentary lesions. Q-switched lasers for pigmentary lesions in Asians had reported a risk of post-inflammatory hyperpigmentation (PIH) up to 25%. Longer pulse widths in the millisecond domains were advocated with reduced risk of PIH. Recently, picosecond lasers of various wavelengths were introduced with proven efficacy in tattoo removal. The objective of this study is to assess the efficacy and safety of a novel picosecond 755-nm alexandrite laser for the treatment of benign pigmented lesions in Asians retrospectively. METHODS: A list of all patients who received picosecond 755-nm alexandrite laser treatment at a private dermatology center in Hong Kong was included. Those who had any other laser or topical treatment during the period of picosecond laser treatment were excluded. The age, skin phototype, type of pigmentary lesion, number of treatments performed was recorded. The baseline and most recent standardized photographs were assessed by trained physicians for comparison. A score of 0-4, representing poor 0-24%, fair 25-49%, good 50-74%, excellent 75-95%, and complete 95%+ improvement was given. Adverse events associated with the laser treatment were also recorded. All patients were followed up until 6 months after the last laser session. RESULTS: A total of 13 subjects were included in the present study. The number of treatment sessions received ranged from one to seven. The benign pigmentary lesions consist of Nevus of Ota, café-au-lait patches, lentigines, Becker's nevus, Hori's macules, and nevus spilus. Among patients with Nevus of Ota, one patient achieved complete clearance after four treatments and two other patients had excellent clearance after three and four sessions, respectively. Patients with café-au-lait had fair to good clearance after one to seven treatment sessions. One patient who has Hori's macules was resistant to laser treatments and a fair response was achieved after eight treatments. In the present series, two patients (4.8%) developed transient hypopigmentation, which had improved upon subsequent follow-up in both cases and none had post-inflammatory hyperpigmentation. CONCLUSIONS: The novel picosecond 755-nm alexandrine laser is effective for the treatment of benign pigmentary lesions in Chinese, especially for the clearance of Nevus of Ota. Picosecond laser appears to be associated with a much lower risk of PIH for treatment of pigmentary lesions in Asians.

HLA-B*58:01 screening to prevent allopurinol-induced severe cutaneous adverse reactions in Chinese patients with chronic kidney disease.

Human leukocyte antigen (HLA)-B*58:01 allele is a significant risk factor for allopurinol-induced severe cutaneous adverse reactions (SCARs) which is potentially fatal. In some studies, chronic kidney disease (CKD) was also implicated to compound the risk of SCARs. We aim to investigate if pre-treatment HLA-B*58:01 screening can prevent allopurinol-induced SCARs in Chinese patients with CKD and its cost-effectiveness. We prospectively recruited Chinese CKD patients who required allopurinol during 2011-2015 and performed pre-treatment HLA testing (HLA screening group). Patients tested positive for HLA-B*58:01 were refrained from allopurinol while those tested negative were prescribed allopurinol. The incidence of SCARs in the HLA screening group was compared with the historical control in previous 5 years and the cost-effectiveness of HLA testing was analyzed. In the historical control (2006-2010), 3605 patients on allopurinol were screened, 22 out of 1027 (2.14%) CKD Chinese patients newly started on allopurinol developed SCARs, including 6 SJS/TEN. In the HLA screening group, 28 out of 192 patients (14.6%) tested HLA-B*58:01 positive were advised to avoid allopurinol; 156 out of 164 HLA-B*58:01-negative patients received allopurinol and none developed SCARs. The incidence rate of SCARs was significantly lower in the HLA screening group compared with controls (0% vs 2.14% respectively, p = 0.037*). The targeted HLA screening approach was associated with lower healthcare costs compared with no HLA screening (US$ 92,430 vs US$ 281,226). Pre-treatment HLA-B*58:01 screening is cost-effective to target on patients with CKD in Chinese to prevent allopurinol-induced SCARs.

Efficacy and safety of tacrolimus ointment monotherapy in chinese children with atopic dermatitis.

OBJECTIVE: To assess the efficacy and patients' tolerance of topical tacrolimus ointment for the treatment of atopic dermatitis in Chinese children during hot and humid seasons. METHODS: Tacrolimus ointment at a concentration of 0.03% was applied for up to 4 weeks. Patients were assessed at weekly intervals for adverse events and efficacy. RESULTS: Thirty-four patients completed the study. Twenty-seven percent of patients showed greater than 75% improvement according to the investigators' Global Evaluation of Clinical Response from Week 1 onward. The mean patients' assessment of treatment effects and Eczema Area Severity Index decreased by 60% after treatment for 4 weeks (p<0.001), and the mean score for patients' assessment of pruritus decreased by 41% at Week 4 (p<0.001). Pruritus and burning sensation were the two main adverse events reported. CONCLUSIONS: The short-term monotherapy of childhood atopic dermatitis with tacrolimus ointment is well tolerated and effective during the hot and humid seasons in Hong Kong.

Cutaneous adverse effects of lithium: epidemiology and management.

Acneiform eruption, psoriasis, folliculitis, and maculopapular eruption have been described as adverse reactions to lithium therapy. In controlled studies, patients treated with lithium developed more cutaneous reactions, particularly acne and psoriasis, than patients receiving other psychotropics, with a prevalence in lithium-treated patients as high as 45%. Male patients taking lithium are more susceptible to developing cutaneous reactions than their female counterparts. Lithium tends to worsen or precipitate cutaneous conditions that are characterized by the pathological findings of neutrophilic infiltration. As lithium-related cutaneous adverse effects can be distressing to patients and may affect medication compliance, attention should be paid to skin problems in patients receiving lithium therapy. Management without cessation of lithium therapy is usually feasible except in some patients with psoriasis that is resistant to treatment. Paradoxically, therapeutic effects of topically applied lithium have been noted in seborrheic dermatitis and recurrent herpes infections.

A community-based epidemiological study of acne vulgaris in Hong Kong adolescents.

Using a questionnaire survey, the prevalence and severity of acne were assessed in a randomized sample of 522 persons (aged 15-25 years) out of 5,522 telephone interviews in Hong Kong. The prevalence of self-reported acne was 91.3%. At the time of interview, 52.2% had acne. More acne scars and pigmentation were present (52.6%) than in a Western population; 26.6% were disturbed psychologically by acne and 82.9% by its physical appearance. Only 2.4% had sought the advice of a doctor for managing acne, while 41.5% had tried some form of medical treatment. Topical treatment comprised 94.7% of medications used for acne. The results show that acne and its complications are common problems. The treatment of acne scars and pigmentation is difficult and complicated by Asian skin phototypes. The findings suggest the need for refined educational programmes to ensure that adolescents know what effective treatments are available so that complications can be reduced.

Aetiology in sixteen cases of toxic epidermal necrolysis and Stevens-Johnson syndrome admitted within eight months in a teaching hospital.

Toxic epidermal necrolysis and Stevens-Johnson syndrome are serious cutaneous reactions associated with significant mortality and morbidity. Eight patients with toxic epidermal necrolysis and eight patients with Stevens-Johnson syndrome were admitted consecutively to a single centre between August 2001 and March 2002. An aetiological study including viral serology and PCR was performed in view of the clustering of admissions related to these two conditions. The majority of cases were drug induced, the drug most commonly involved being allopurinol (toxic epidermal necrolysis, 50%; Stevens-Johnson syndrome, 13%). Two cases were related to drug abuse. Possible aetiological co-factors were cancers, radiotherapy and renal failure. No association with viral infection, including human herpesvirus-6 and parvovirus B19, was detected in the present series. Early diagnosis and prompt withdrawal of suspected drugs remain the most important measures in managing this condition. Further studies to identify the co-factors precipitating severe cutaneous drug reactions are warranted.

Primary CD30+ve cutaneous T-cell lymphoma associated with chronic burn injury in a patient with longstanding psoriasis.

An increased incidence of lymphoma has been reported in psoriatic patients, but most cases are nodal B-cell lymphoma. We report a unique case of CD30-expressing cutaneous T-cell lymphoma arising from underlying psoriatic plaque after intractable caustic burns and cellulitis in the palm of a patient with generalized chronic plaque psoriasis. Molecular studies confirmed a localized clonal T-cell expansion, and the lesion responded dramatically to multiagent chemotherapy. The case highlighted the possible role of chronic systemic and local T-cell activation in the pathogenesis of primary CD30+ve cutaneous T-cell lymphoma, and the importance of histologic assessment in chronic nonhealing skin lesions.

Prospective study of pulsed dye laser in conjunction with cryogen spray cooling for treatment of port wine stains in Chinese patients.

BACKGROUND: Pulsed dye laser (PDL) in conjunction with cryogen spray cooling (CSC) is effective in improving efficacy and safety for treatment of port wine stains (PWSs) in whites. However, for dark-skinned patients such as Chinese, only retrospective studies have been performed. OBJECTIVES: To compare prospectively clinical efficacy in terms of blanching and acute and long-term adverse effects of PDL alone and PDL-CSC for treatment of PWSs in Chinese patients. METHODS: Thirty-five Chinese patients (13 males and 22 females) were recruited, and 131 treatments were performed. Half of the test area on the PWS was treated with PDL alone, and the contralateral half was treated with PDL-CSC. The degree of PWS blanching was objectively assessed by spectrophotometer. Skin textural changes were detected by cutometer. All measurements were taken at baseline and before each subsequent laser treatment. Patients were interviewed immediately after treatment and again the following week using a visual analog scale questionnaire to assess the degree of pain and swelling. Occurrence of blisters was noted during each follow-up visit. Patients were evaluated for evidence of long-term adverse effects such as dyspigmentation and scarring after three treatments. RESULTS: Statistically significant higher fluences were used on the PDL-CSC-treated group. The percentage change in the spectrophotometer a* value was significantly greater using PDL-CSC, indicating that there was more PWS blanching after treatment. There was no significant difference in the incidence of skin textural changes after three treatments with PDL alone or PDL-CSC. The immediate pain scores were significantly higher for PDL alone than with PDL-CSC. Blisters were significantly more common on the area treated using PDL alone than PDL-CSC. The overall incidence of long-term adverse effects was not significantly different between the PDL alone and PDL-CSC treatments. PDL-CSC was also the preferred treatment modality for most patients. CONCLUSIONS: PDL-CSC was more effective than PDL alone for blanching of PWS in Chinese patients. Moreover, PDL-CSC was better tolerated and resulted in a lower incidence of acute adverse effects such as blistering.

A prospective case control study of the association of Gianotti-Crosti syndrome with human herpesvirus 6 and human herpesvirus 7 infections.

Gianotti-Crosti syndrome (GCS) is known to be associated with hepatitis B and Epstein-Barr virus (EBV) infections. Apart from a single case report based on serology alone, there are no published data on an association between GCS and human herpesvirus 6 (HHV-6) and human herpesvirus 7 (HHV-7) primary infections or reactivations. Our aim was to investigate the association between GCS and HHV-6 and HHV-7 infections. Ten patients diagnosed with GCS at a primary care practice over an 18-month period were recruited. Controls were age- and sex-matched patients with unrelated symptoms requiring venepuncture for other indications. Blood specimens were collected from patients and controls at presentation, and from patients 4 weeks later. Virologic evidence of HHV-6 and HHV-7 infection was sought in peripheral blood leukocytes and plasma using polymerase chain reaction (PCR) for viral DNA, reverse transcriptase polymerase chain reaction (RT-PCR) for HHV-6 U91 mRNA transcripts, and serology. Serology for EBV and hepatitis B virus was done. In contrast to the 10 controls, 2 patients (both infants) with clinically diagnosed GCS had evidence of active HHV-6 infection. This was demonstrated by detection of viral DNA in the absence of antibody in the acute plasma specimens and HHV-6 DNA viral loads of more than 5.3 log10 genome copies/5 microl in the whole blood specimens, a profile previously shown to be diagnostic of recent primary HHV-6 infection. None of the patients had evidence of recent EBV or hepatitis B infection. We conclude that primary HHV-6 infection may be associated with GCS in some infants.