Real-life study showing uncontrolled rhinosinusitis after sinus surgery in a tertiary referral centre.

RATIONALE: The European Position Paper on Sinusitis (EPOS) guidelines provide composite criteria to evaluate chronic rhinosinusitis (CRS) control, taking into consideration the severity of patients' symptoms, aspect of nasal mucosa and medical intake as parameters of CRS control. OBJECTIVES: To study the degree of CRS control using novel EPOS control criteria at 3-5 years after a functional endoscopic sinus surgery (FESS) and correlate these data to symptoms scores. METHODS: Adult CRS patients (n = 560) who had undergone bilateral FESS for chronic inflammatory sinonasal disease 3-5 years prior to the study were included. Patients received a postal questionnaire asking for control items according to EPOS control criteria, visual analogue scale (VAS) scores for total and individual sinonasal symptoms, sinonasal outcome test (SNOT)-22 and Short Form (SF)-36 questionnaires. MEASUREMENTS AND MAIN RESULTS: About 19.5% of CRS patients were well controlled, with 36.8% of patients being partly controlled and 43.7% uncontrolled. The levels of control corresponded to mean total VAS, SNOT-22 and SF-36 scores. Subgroup analysis revealed that female gender, aspirin intolerance and revision FESS were associated with higher prevalence of uncontrolled CRS, whereas allergy, asthma and smoking status did not alter the percentage of patients in each category of control. In 81 patients attending the outpatient clinic, nasal endoscopy changed classification in only four patients (4.9%). CONCLUSIONS: Based on the novel EPOS control criteria, at least 40% of CRS patients are uncontrolled at 3-5 years after FESS. Therefore, better treatment strategies leading to higher disease control are warranted in CRS care.

Vitiligo Area Scoring Index and Vitiligo European Task Force assessment: reliable and responsive instruments to measure the degree of depigmentation in vitiligo.

BACKGROUND: Vitiligo is a common skin disorder causing depigmented macules that can impair a patient's quality of life. Currently, there are no standardized outcome measures to assess the degree of depigmentation. Moreover, there is limited knowledge on the measurement properties of outcome measures in vitiligo. OBJECTIVES: To assess the reliability and responsiveness of the Vitiligo Area Scoring Index (VASI) and the Vitiligo European Task Force assessment (VETFa), two well-described clinician-reported outcomes. METHODS: We included three vitiligo patient groups. In one group of 31 patients, the interobserver reliability was assessed by three observers. In 27 patients the intraobserver reliability was assessed by two repeated measures by one of the observers. To assess the responsiveness the repigmentation was calculated after 6 months of phototherapy in 33 patients and tested against hypotheses. RESULTS: The interobserver reliability was high for VASI [intraclass correlation coefficient (ICC) 0·93] and VETFa depigmentation (ICC 0·88). The intraobserver reliability was high for VASI (ICC 0·93) and VETFa depigmentation (ICC 0·97). The smallest detectable changes (SDCs) were 7·1% and 10·4% for interobserver reliability and 4·7% and 2·9% for intraobserver reliability in VASI and VETFa depigmentation, respectively. All four responsiveness hypotheses formulated a priori were confirmed. CONCLUSIONS: VASI and VETFa are reliable and responsive instruments to assess the degree of depigmentation in vitiligo. VASI and VETFa for depigmentation are potential instruments for vitiligo research in the future. However, for use in individual patient care, caution is needed when interpreting score changes in individual patients because of the relatively large SDC.

The validity, reliability and acceptability of the SAVASI; a new self-assessment score in vitiligo.

BACKGROUND: Vitiligo is a common depigmenting skin disorder that can influence a patient's quality of life. Although patient-orientated medicine is an emerging concept, a self-assessment tool to assess the degree of depigmentation in vitiligo is not yet available. Therefore, we developed the SAVASI, a self-assessment tool that uses the same basic principles as the VASI. OBJECTIVE: To assess the validity, reliability and acceptability of the SAVASI. METHODS: To assess the validity of the SAVASI, we compared the scores assessed by the patient with the scores of the VASI assessed by the physician. To assess the intra-rater reliability, the correlation between the baseline SAVASI and the SAVASI after 2 weeks was calculated. To assess the acceptability, patients indicated the time needed to complete the SAVASI and the patient assessed the difficulty of the questionnaire on a five-point scale. The Skindex-29 was used to determine the quality of life. The overestimation of the SAVASI compared to the VASI was calculated by subtracting the VASI scores off from the SAVASI scores. RESULTS: A high correlation between the VASI and the SAVASI (ICC 0.97, 95% CI: 0.95-0.98) was found in 60 patients. The intra-rater reliability of the SAVASI (ICC 0.75, 95% CI 0.54-0.87) was adequate in 31 patients. Fifty (83%) of the patients completed the questionnaire within 10 min and only five (8%) of the patients considered the SAVASI hard. We found no correlation between overestimation of the SAVASI score and the Skindex-29 score. CONCLUSION: The SAVASI is a valid, reliable and acceptable self-assessment tool to measure the degree of depigmentation in vitiligo. With the SAVASI the degree of depigmentation can reliably be assessed by the patient themselves which can be useful in large (epidemiological) studies. Furthermore, this could contribute to the patient's disease insight and therapy loyalty.

Diffraction-limited storage rings - a window to the science of tomorrow.

This article summarizes the contributions in this special issue on Diffraction-Limited Storage Rings. It analyses the progress in accelerator technology enabling a significant increase in brightness and coherent fraction of the X-ray light provided by storage rings. With MAX IV and Sirius there are two facilities under construction that already exploit these advantages. Several other projects are in the design stage and these will probably enhance the performance further. To translate the progress in light source quality into new science requires similar progress in aspects such as optics, beamline technology, detectors and data analysis. The quality of new science will be limited by the weakest component in this value chain. Breakthroughs can be expected in high-resolution imaging, microscopy and spectroscopy. These techniques are relevant for many fields of science; for example, for the fundamental understanding of the properties of correlated electron materials, the development and characterization of materials for data and energy storage, environmental applications and bio-medicine.

Pinhole diffraction holography for fabrication of high-resolution Fresnel zone plates.

Fresnel zone plates (FZPs) play an essential role in high spatial resolution x-ray imaging and analysis of materials in many fields. These diffractive lenses are commonly made by serial writing techniques such as electron beam or focused ion beam lithography. Here we show that pinhole diffraction holography has potential to generate FZP patterns that are free from aberrations and imperfections that may be present in alternative fabrication techniques. In this presented method, FZPs are fabricated by recording interference pattern of a spherical wave generated by diffraction through a pinhole, illuminated with coherent plane wave at extreme ultraviolet (EUV) wavelength. Fundamental and practical issues involved in formation and recording of the interference pattern are considered. It is found that resolution of the produced FZP is directly related to the diameter of the pinhole used and the pinhole size cannot be made arbitrarily small as the transmission of EUV or x-ray light through small pinholes diminishes due to poor refractive index contrast found between materials in these spectral ranges. We also find that the practical restrictions on exposure time due to the light intensity available from current sources directly imposes a limit on the number of zones that can be printed with this method. Therefore a trade-off between the resolution and the FZP diameter exists. Overall, we find that this method can be used to fabricate aberration free FZPs down to a resolution of about 10 nm.

Q-switched laser depigmentation in vitiligo, most effective in active disease.

BACKGROUND: In widespread vitiligo, when repigmentation therapies are no longer feasible, Q-switched lasers can be used to remove the remaining disfiguring pigmentation. However, little literature is available on the long-term effects of Q-switched laser treatment in patients with vitiligo, and the variables influencing the effect of treatment are unknown. OBJECTIVE: To evaluate retrospectively the effectiveness, safety and patient satisfaction of Q-switched ruby (QSR) laser-induced depigmentation in widespread vitiligo. METHODS: We performed a retrospective study on well-documented patients with vitiligo with widespread lesions who received depigmentation therapy with the QSR laser between 2000 and 2012 in our institute. Eligible patients were asked to visit our institute for assessment of depigmentation and to fill in a questionnaire on patient satisfaction and disease variables. RESULTS: After a mean follow-up of 13 months, 48% of the 27 included patients showed > 75% depigmentation. Patients with active disease at the time of treatment had significantly better results than patients with stable disease (P < 0·05). Twenty-three (85%) patients were satisfied after treatment. Eighteen patients (67%) reported temporary side-effects after treatment. None of the patients reported adverse effects, such as scars or infections. CONCLUSION: Q-switched ruby laser therapy is effective in approximately half of patients treated; it is a safe treatment with a high patient satisfaction. Patients with active vitiligo show better results after treatment than patients with stable vitiligo. Therefore, in patients with stable vitiligo resistant to trial treatment, we advise postponing treatment until their vitiligo becomes active.

Provoking factors, including chemicals, in Dutch patients with vitiligo.

BACKGROUND: In vitiligo, many provoking factors have been described, but epidemiological data, especially on the role of contact with chemicals, are scarce. OBJECTIVE: To obtain an insight into the patient-reported factors provoking vitiligo, including contact with chemicals. METHODS: A retrospective cohort study was conducted on all 1264 patients with vitiligo who visited the Netherlands Institute for Pigment disorders from January 2003 to December 2007. Patients for whom an exogenous provoking factor was recorded were sent a questionnaire. Subsequently, patients who mentioned a chemical provoking factor were contacted to elucidate the alleged causal relationship between exposure to the chemical and the onset of vitiligo. RESULTS: A total of 300 out of the 1264 patients indicated that provoking factors had played a role in their disease. Two hundred and forty-six patients were sent a questionnaire, which was returned by 177 (response rate of 72%). Emotional stress was indicated as a provoking factor in 98 patients (55.4%), 51 patients (28.8%) recorded sunburn, 34 patients (19.2%) recorded mechanical factors and 20 patients (11.3%) other factors. Of 29 patients (16.4%) who indicated a chemical factor, a presumed causal relationship could be corroborated in four. The chemicals involved were para-tertiary butylphenol (n = 2), captan (n = 1) and diphencyprone (n = 1). CONCLUSION: The majority of the patients with vitiligo from this study did not mention provoking factors, but the ones who did point to emotional stress in more than half of the cases. Of the 29 patients who assigned chemical provoking factors, solvents were mainly indicated. However, a presumed relationship with the chemical could be corroborated in only four patients.

Radiation-induced melanoma-associated leucoderma, systemic antimelanoma immunity and disease-free survival in a patient with advanced-stage melanoma: a case report and immunological analysis.

BACKGROUND: Melanoma is an immunogenic tumour. The development of skin depigmentation or melanoma-associated leucoderma (MAL) has been associated with favourable clinical outcome in patients with metastatic melanoma, especially after immunotherapy. Evidence for clinically meaningful enhancement of melanoma-directed autoimmunity, as indicated by MAL, after radiotherapy without immunotherapy has not yet been published. OBJECTIVES: We investigated whether a patient with stage IV melanoma, who developed leucoderma in the irradiated skin areas following radiotherapy and experienced exceptional disease-free survival of 3 years despite brain metastasis, possessed antimelanoma immunity that could be linked to the favourable disease course. METHODS: A detailed immunological analysis was performed consisting of immunohistochemistry of several melanoma tissues, and analyses of T cells isolated from the blood and MAL skin tissue for melanocyte/melanoma specificity and functionality, as well as the presence of a melanoma-specific antibody response. RESULTS: Immunological analyses showed the presence of CD8+ T cells and antibody responses directed against melanocyte differentiation antigens expressed in the primary tumour, lymph node and brain metastasis, indicating adequate tumour recognition by activated T cells. CONCLUSION: The immune responses found in this patient, probably enhanced by radiotherapy, are thought to have contributed to his favourable clinical course. Radiotherapy may act as local immunotherapy in patients with melanoma by destroying melanocytes, leading to the induction, or enhancement, of already existent antimelanoma immunity. As in patients treated with immunotherapy, this may lead to MAL, also at distant sites from the treated area. This patient is a clear example of the positive prognostic value of MAL, which is possibly induced by radiotherapy, for patients with melanoma.

Decreased risk of melanoma and nonmelanoma skin cancer in patients with vitiligo: a survey among 1307 patients and their partners.

BACKGROUND: Vitiligo is a common skin disease characterized by autoimmune melanocyte destruction. Recent genetic studies suggest a lower susceptibility to melanoma in patients with vitiligo; however, lifetime melanoma prevalence in patients with vitiligo has not previously been studied. Nonmelanoma skin cancer (NMSC) prevalence has been studied, but only in small studies and with contradictory results. OBJECTIVES: This retrospective, comparative cohort survey was designed to assess lifetime prevalences of melanoma and NMSC in patients with vitiligo compared with nonvitiligo controls. METHODS: Patients with nonsegmental vitiligo, who visited our clinic between January 1995 and September 2010, and were aged 50 years or older at the time of the study, were invited to participate in a postal survey. The questions regarded demographics, vitiligo characteristics, phototherapy history, skin cancer risk factors and the number of skin cancers experienced during the patient's lifetime. Patients were asked to have their partner fill in a control questionnaire. All skin cancers were validated by a pathology report. In total 2635 invitations were sent and 1307 eligible questionnaires were returned (50%). Multivariate logistic regression models were used to quantify adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for associations between vitiligo and lifetime prevalences of melanoma and NMSC. RESULTS: Adjusted for confounders, patients with vitiligo had a threefold lower probability of developing melanoma (adjusted OR 0·32; 95% CI 0·12-0·88) and NMSC (adjusted OR 0·28; 95% CI 0·16-0·50). Subgroup analyses of patients treated with narrowband ultraviolet (UV) B, and psoralen and UVA did not show dose-related trends of increased age-adjusted lifetime prevalence of melanoma or NMSC. CONCLUSIONS: Our findings suggest that patients with vitiligo have a decreased risk of both melanoma and NMSC.

Digital image analysis vs. clinical assessment to evaluate repigmentation after punch grafting in vitiligo.

BACKGROUND: Repigmentation as a treatment outcome in vitiligo is not assessed in a standard way, making results of clinical trials hard to compare. Different types of repigmentation assessments after punch grafting have not been compared so far. OBJECTIVE: To compare assessments of repigmentation by a digital image analysis system (DIAS) with those of clinical observers and patients after punch grafting for vitiligo. METHODS: One vitiligo patch was selected in each patient (n = 21). This patch was treated with the punch grafting technique. The grade of repigmentation (%) after 3 months was assessed by: (i) DIAS; (ii) 3 clinical observers ; and (iii) the patient, scoring the grade of repigmentation on photographs. Physicians and patients also evaluated the global result on a 7-point scale. RESULTS: There was an almost perfect agreement between the three clinical observers and the DIAS (ICC 0.83). As expected, variation was found between the clinical observers. Patients' scores showed a moderate agreement with the DIAS (ICC 0.49) and a poor agreement with the physicians (ICC 0.28). Overall, the patients were more satisfied with the results than the physicians. CONCLUSIONS: Whereas the results of the digital and clinical assessments were comparable, patients' ratings diverged. The DIAS can overcome the inevitable differences between observers, which are intrinsic to a visual grading method, and is advisable for clinical trials on vitiligo to objectively assess repigmentation in limited lesions.

Long-pulsed 1064 nm Nd:YAG laser improves hypertrophic port-wine stains.

BACKGROUND: Hypertrophic port-wine stains (PWS) usually respond poorly to pulsed dye laser treatment. The long-pulsed 1064 nm Nd:YAG laser can target deeper situated vessels and may therefore be more effective. OBJECTIVE: To evaluate the efficacy and safety of the Nd:YAG laser for the treatment of hypertrophic PWS. METHODS: In a retrospective cohort study, all hypertrophic PWS patients treated with the Nd:YAG laser between 2005 and 2011 were invited for follow-up. Clinical improvement was assessed using Physician Global Assessment (PhGA) and Patient Global Assessment (PGA). RESULTS: Assessment was obtained in 32 of 44 eligible patients (mean age 51.4 years), after a mean of 2.8 (SD ± 2.1) Nd:YAG laser treatments. Good or excellent improvement of hypertrophy was found in a majority of patients, both by PhGA (91%) and PGA (93%). Good or excellent improvement of colour was found in 63% of patients by PhGA, and in 87% by PGA. Recurrence of hypertrophy was seen in three patients. All but two patients would recommend Nd:YAG treatment to other patients. Mild to moderate scars were seen in seven patients, hypopigmentation in 14 patients. CONCLUSION: The 1064 nm Nd:YAG laser is highly effective in the treatment of hypertrophic PWS with only a few treatments needed. Mostly mild side effects were seen in half of all patients. Hypertrophy seems to respond better than colour. To further improve colour, a combination with pulsed dye laser treatment is advisory. Observation of immediate clinical endpoints is important when using the Nd:YAG laser, to optimize outcomes and reduce side effects.

Melanocyte antigen-specific antibodies cannot be used as markers for recent disease activity in patients with vitiligo.

BACKGROUND: Objective parameters to assess disease activity in non-segmental vitiligo are lacking. Melanocyte antigen-specific antibodies are frequently found in the sera of patients with vitiligo and the presence of these antibodies may correlate with disease activity. OBJECTIVE: To investigate the relationship between melanocyte antigen-specific antibodies and recent disease activity in patients with vitiligo and to evaluate the potential usefulness of this objective parameter in daily clinical practice. METHODS: The prevalence of tyrosinase, melanoma antigen recognized by T-cells-1 (MART1), melanin-concentrating hormone receptor-1 (MCHR1), gp100 and tyrosine hydroxylase (TH) antibodies was evaluated in 21 patients with non-segmental vitiligo and in 20 healthy controls. RESULTS: In 21 patients, nine (42.8%) showed antibody responses against tyrosinase, MART1, MCHR1, gp100 or TH. No antibody responses were found in the 20 controls. No correlation was found between the presence of antibodies and recent disease activity or other clinical characteristics such as age, gender, extension and duration of vitiligo. CONCLUSIONS: In this study, 42.8% of the vitiligo patients showed an antibody response to melanocyte antigen-specific antigens. However, the presence of antibodies against melanocytes did not correlate with recent disease activity or other relevant disease parameters, and for the moment screening for these antibodies in individual patients does not appear to be clinically relevant.

Anisotropic pair correlations and structure factors of confined hard-sphere fluids: an experimental and theoretical study.

We address the fundamental question: how are pair correlations and structure factors of hard-sphere fluids affected by confinement between hard planar walls at close distance? For this purpose, we combine x-ray scattering from colloid-filled nanofluidic channel arrays and first-principles inhomogeneous liquid-state theory within the anisotropic Percus-Yevick approximation. The experimental and theoretical data are in remarkable agreement at the pair-correlation level, providing the first quantitative experimental verification of the theoretically predicted confinement-induced anisotropy of the pair-correlation functions for the fluid. The description of confined fluids at this level provides, in the general case, important insights into the mechanisms of particle-particle interactions in dense fluids under confinement.

Low yield of routine screening for thyroid dysfunction in asymptomatic patients with vitiligo.

BACKGROUND: Nonsegmental vitiligo is considered to be an autoimmune disease and is known to be associated with other autoimmune diseases, particularly affecting the thyroid. Screening patients with nonsegmental vitiligo for thyroid function and for the presence of thyroid autoantibodies has been recommended. OBJECTIVE: To investigate the prevalence of thyroid dysfunction and thyroid peroxidase-specific (TPO) antibodies in a large cohort of patients with nonsegmental vitiligo in order to help decide whether routine screening is justified. METHODS: A total of 434 adults with nonsegmental vitiligo who were referred to our institute were enrolled. Thyroid function and anti-TPO antibody titres were assessed in those patients who had no history of thyroid disease or recent thyroid screening. RESULTS: Forty-three patients had already been diagnosed with thyroid dysfunction, and in 27 patients the general practitioner had performed a thyroid function test with negative results <3months previously. In these patients, thyroid function assessment was not repeated. The remaining 364 patients were screened for thyroid dysfunction. Overt hypothyroidism was newly diagnosed in three (0·8%) patients; subclinical disease was found in 10 (2·7%) patients and increased levels of TPO antibodies, without thyroid disease, were found in 49 (13·5%) patients. An elevated risk for thyroid disease was found among older women and in women with a positive family history of thyroid disease. CONCLUSION: The overall prevalence of thyroid dysfunction in adult patients with nonsegmental vitiligo was higher than reported in the general population. However, the number of newly diagnosed cases with overt and subclinical thyroid dysfunction in our population was low. Most patients had already been diagnosed by their general practitioner and had symptoms indicative for thyroid disease. Thyroid disease was found predominantly among older women and in subjects with a positive family history of thyroid disease. Thyroid screening including anti-TPO antibodies is advisable in these high-risk subpopulations.

The prevalence of thyroid disease in patients with vitiligo: a systematic review.

BACKGROUND: Thyroid disease has been suggested to be associated with vitiligo. However, the outcomes of prevalence studies on thyroid disease in vitiligo vary widely. OBJECTIVES: To summarize and critically appraise current evidence of the prevalence of thyroid diseases in vitiligo. METHODS: A systematic review was performed searching the electronic databases OVID MEDLINE, OVID EMBASE and PubMed. Guidelines for the critical appraisal of studies on prevalence of a health problem were adapted to evaluate the methodological quality of the included studies. Results were analysed in a meta-analysis with a risk ratio (RR). RESULTS: Forty-eight studies published between 1968 and 2012 met the inclusion criteria. Most of the studies (50%) were of fair methodological quality, whereas 18 studies (38%) were of poor quality and six studies (12%) were of good quality. Thyroid disease, autoimmune thyroid disease and presence of thyroid-specific autoantibodies showed a mean prevalence of, respectively, 15·1%, 14·3% and 20·8% in patients with vitiligo and an RR of, respectively, 1·9, 2·5 and 5·2 (all statistically significant). This review shows an increased prevalence and an increased risk of (autoimmune) thyroid disease in patients with vitiligo compared with nonvitiligo. This risk seems to increase with age. CONCLUSIONS: Clinicians should be aware of this increased risk in patients with vitiligo and should be attentive for symptoms of thyroid disease. To make recommendations on screening for thyroid disease in patients with vitiligo future research of good methodological quality, including differentiation of vitiligo types and the use of standardized outcome measures, is needed.

Ultrahigh-frequency surface acoustic wave transducers on ZnO/SiO2/Si using nanoimprint lithography.

Ultrahigh-frequency surface acoustic wave devices were fabricated on a ZnO/SiO2/Si substrate using step-and-flash nanoimprint lithography combined with hydrogen silsesquioxane (HSQ) planarization. Excellent critical dimension control was demonstrated for interdigital transducers with finger electrode widths from 125 down to 65 nm. Fundamental and higher-order Rayleigh modes up to 16.1 GHz were excited and detected, which is the highest frequency for ZnO-based transducers on silicon reported so far. Surface acoustic modes were confirmed with numerical simulations. Simulation results showed good agreement with the experimental data.

Hypertrophy in port-wine stains: prevalence and patient characteristics in a large patient cohort.

BACKGROUND: Port-wine stains (PWS) may thicken and darken with age. Little is known about the pathogenesis and epidemiology of PWS hypertrophy because of the lack of large studies. OBJECTIVE: We sought to assess the prevalence and characteristics of patients with hypertrophic PWS. METHODS: Medical records and clinical photographs of all patients with PWS visiting our clinic between 2005 and 2009 were examined to identify hypertrophy. Patients were sent questionnaires regarding their hypertrophic PWS. RESULTS: In all, 335 patients (age 0-81 years; 69% female) with PWS were included. Hypertrophy was found in 68 patients (20%; 32 male, 36 female) and classified as thickened (5%), nodular (8%), or both (7%). Color of hypertrophic PWS was mainly red (50%) or purple (44%). Patients with hypertrophy in their PWS were mostly (68%) older than 40 years, and rarely (7%) younger than 20 years. When older than 50 years, 71% of all patients had hypertrophy in their PWS. Median age of onset of PWS hypertrophy was 31 years (12 years for thickened, 39 years for nodular). LIMITATIONS: This was a retrospective study in a selected population. CONCLUSION: Hypertrophy is an important feature in the development of PWS and affects a majority of patients older than 50 years. Depth of color of the PWS is associated with hypertrophy, whereas location and size appear not to be related. More attention should be drawn to therapy and prevention of hypertrophic PWS. Diffuse thickening and nodules should be distinguished, as a different age of onset may indicate different pathomechanisms.

Double pass 595 nm pulsed dye laser at a 6 minute interval for the treatment of port-wine stains is not more effective than single pass.

BACKGROUND: Pulsed dye laser (PDL) is the first choice for treatment of port wine stains (PWS). However, outcome is highly variable and only a few patients achieve complete clearance. The objective of the study was to compare efficacy and safety of single pass PDL with double pass PDL at a 6 minute interval. METHODS: We conducted a randomized within-patient controlled study on PWS resistant to multiple single pass PDL treatments. In each patient two similar PWS areas were randomly allocated to PDL treatment (595 nm, 7 mm spot size, 1.5 mseconds pulse duration) using, as a control treatment, a single pass (12 J/cm(2)) or, as a new treatment, a double pass PDL (11 J/cm(2), second pass 6 minutes after the first pass). Both test areas were treated two times, 8 weeks apart. PWS clearance was assessed by two blinded dermatologists, and by color measurement (L*a*b) using reflectance spectroscopy, at 3 months follow-up. RESULTS: Sixteen out of 17 included patients completed follow-up. The mean number of treatments before inclusion was 15. Overall color assessed by spectrophotometer showed no improvement for either single or double pass PDL. Blinded Physician Global Assessment and Patient Global Assessment showed a high variability in outcome, with mostly only moderate improvement of the PWS for either single pass or double pass PDL. Furthermore, there was no significant difference in any of the outcomes between single pass and double pass PDL. CONCLUSION: At the chosen settings and after two treatment sessions, double pass PDL at a 6 minute interval does not result in improved clearance of PWS as compared to single pass treatment.