Chronic actinic dermatitis in Asian skin: a Singaporean experience

Background/purpose: To study the characteristics of chronic actinic dermatitis (CAD) in a heterogeneous group of Singaporean patients. Methods: The photobiologicial features of all patients phototested and diagnosed with CAD from January 2005 to December 2009 were examined retrospectively. Results: Fifty‐eight patients were diagnosed as having CAD. The mean age at diagnosis was 62 years (range 35–83). Forty‐one were (70.7%) Chinese, six (10.3%) Indians, eight (13.8%) Malays, and three (5.2%) Others. Forty‐seven were (81.0%) male and 11 (19.0%) were female. Forty‐nine (84.5%) had Fitzpatrick skin phototype IV and nine (15.5%) had phototype V. Three of 26 (11.5%) tested for human immunodeficiency virus were positive. The face, neck, and forearms were most commonly affected. Thirty‐two patients (55.2%) had reduced minimal erythema dose (MED) to both ultraviolet B (UVB)and ultraviolet A (UVA), 23 patients (39.7%) had lowered MED to UVB only, while three (5.1%) had reduced MED to UVA only. Patients were followed up for a mean of 16.8 months. All were treated with photoprotection and topical steroids; however, a few required oral immunosuppression with partial improvement. Conclusion: In Singapore, CAD was seen more commonly in elderly Chinese males of Fitzpatrick skin phototype IV. Reduced MED to both UVB and UVA was the most common phototest finding.     

Treatment of moderate and severe adult chronic atopic dermatitis with narrow‐band UVB and the combination of narrow‐band UVB/UVA phototherapy

The phototherapy is a safe and effective technique for the treatment of adult patients with atopic dermatitis (AD). The treatment of chronic forms of the disease is most often done with narrow‐band UVB (NB‐UVB). There also exist effective phototherapy options against the AD. The aim of this study was to asses if the combination of NB‐UVB with UVA was more effective than the treatment with only NB‐UVB against adult chronic AD. We carried out a prospective and observational study. Adult patients with chronic AD with more than 50% of the total body surface area affected (TBSA) were included. The affected TBSA was calculated using the so‐called “rule of nines.” Patients with a clearance rate >75% of the initial affected TBSA or complete clearance rate were considered as complete response (CR). An analogue scale from 0 to 10 was used to measure the improvement grade of the pruritus. The treatments were repeated three times a week. The initial doses of NB‐UVB and UVA were determined by patient's phototype. The treatments were performed using a phototherapy booth (UV7002, Walmann, Villingen‐Schwenningen, Germany^®) with TL01 and UVA fluorescent lamps. Statistical analysis was performed with SPSS^® (IBM, New York, NY) for Windows 21.0. A total of 26 patients with adult chronic AD were included in the study, 16 patients were treated with UVB‐BE and 10 patients with the combined treatment option NB‐UVB/UVA. The mean value of cumulative doses and the mean number of performed treatments were similar between both groups of patients (p > 0.05). The mean value of duration of response was significantly higher in the patients treated only with NB‐UVB, 101 versus 6.8 months (p ≥ 0.05). No differences were observed for the patients that showed complete response (p = 0.42) and in the analogue scale of pruritus (p > 0.005). In our study, the patients treated with the combination of NB‐UVB and UVA were similar to the patient that were only treated with NB‐UVB e. Further prospective and controlled studies have to be performed in order to determine the dosing regimens of phototherapy in adult patients with AD.     

窄谱中波紫外线治疗慢性光线性皮炎的方案及影响因素分析

目的 探讨窄谱中波紫外线(NB-UVB)光疗法治疗慢性光线性皮炎(CAD)的方案及影响治疗实施的相关因素.方法 对2008年1月至2015年6月间在复旦大学附属华山医院皮肤科接受NB-UVB光疗的CAD患者的人口学资料、光生物学测试结果、治疗参数和临床反应进行回顾性分析.采用SAS9.3软件对完成与未完成NB-UVB光疗者的临床资料通过t检验或x2检验进行比较.结果 共79例CAD患者接受NB-UVB光疗,均为Fitzpatrick Ⅳ型皮肤,其中61例(77％)完成治疗,18例(23％)因无法耐受而退出.完成治疗者中,NB-UVB起始照射剂量为(0.08±0.01) J/cm2,终点照射剂量为(0.32±0.08) J/cm2,累积照射量为(5.9±2.5)J,治疗次数为(28±8)次.52例(85％)在照射剂量达到0.30 J/cm2时皮损基本清除.19例患者在光疗结束后再次进行光试验,其中16例对UVA敏感的患者中6例UVA-MED恢复正常,6例明显改善;16例对UVB敏感的患者中11例UVB-MED恢复正常,3例明显改善.单因素分析显示,患者性别、年龄、病程、长波紫外线(UVA)敏感度、UVB敏感度以及光斑贴试验和斑贴试验结果在完成治疗和未完成治疗患者之间比较,差异均无统计学意义(P＞0.05).结论 于春季开始、起始剂量为0.08 J/cm2、终点剂量为0.30 J/cm2、疗程28次左右是适合CAD患者的NB-UVB光脱敏方案,可有效降低患者对UVA和UVB的敏感性.不同性别、年龄、病程以及光敏感程度的CAD患者均可尝试用NB-UVB光疗法治疗.     

Narrow-band ultraviolet B is a useful and well-tolerated treatment for vitiligo

BACKGROUND: The treatment of vitiligo remains a challenge. OBJECTIVE: The purpose of this article is to review our results and experience with narrow-band ultraviolet (UV) B phototherapy for vitiligo. METHODS: This is a retrospective analysis of our experience and results with patients with vitiligo who were treated with narrow-band UVB between November 1998 and November 1999. Narrow-band UVB phototherapy was given as monotherapy 3 times a week. The starting dose was 280 mJ/cm(2), with 15% dose increments at each subsequent treatment. RESULTS: Seven patients were able to be evaluated for the purposes of this analysis. Their ages ranged from 19 to 59 years (mean, 37.6 years). Three patients had Fitzpatrick skin phototype IV and V, and 4 had phototypes II and III. Five of the 7 patients achieved more than 75% repigmentation with a mean of 19 treatments; the mean duration of disease was 13 months. The remaining two patients had 50% and 40% repigmentation after 46 and 48 treatments, respectively. Their mean duration of disease was 132 months. Adverse effects were mild erythema and pruritus. CONCLUSION: This treatment protocol resulted in rapid repigmentation in many patients, including those with skin phototypes IV and V. In accordance with previous studies, this report indicates that narrow-band UVB is a useful and well-tolerated therapy for vitiligo.     

Pinpoint papular polymorphous light eruption in Asian skin: a variant in darker-skinned individuals

Background: Polymorphous light eruption (PMLE) is the most common idiopathic but probably immunologic photodermatosis and has wide morphological variants.
Methods: The photobiological features of all patients diagnosed with the pinpoint papular variant of PMLE at a tertiary dermatology centre in Singapore over a five-year period were retrospectively examined.
Results: Twenty-one patients were reviewed from 2003 to 2007. There were 11 (52.4%) Chinese, four (19%) Malays, five (23.8%) Indians and one (4%) Cambodian. 14 (66.7%) were males and seven (33.3%) were females. The face/neck (48%) and arms/forearms (95%) were most often affected. Nineteen (90.5%) had Fitzpatrick skin phototype IV and two (9.5%) had skin phototype V. Six (28.6%) had decreased minimal erythema dose (MED) to ultraviolet B (UVB) light only, one (4.8%) had decreased MED to ultraviolet A (UVA) light only and one had decreased MED to both UVA and UVB. Four patients had photoprovocation test done, of which three had positive testing to UVA and one had negative testing to both UVA and UVB. Two histological subtypes were found in our patients, one showing perivascular dermatitis and the other consistent with lichen nitidus.
Conclusion: Our data suggest that pinpoint papular PMLE is not uncommon in darker-skinned individuals in our cohort.     

Therapeutic evaluation of UVB‐targeted phototherapy in vitiligo that affects less than 10% of the body surface area*

Background Current treatments for vitiligo include different therapeutic modalities, such as corticosteroids, immunomodulators, pseudocatalase, skin grafts, diverse types of phototherapy [ultraviolet B (UVB), psoralen plus UVA (PUVA), narrow‐band UVB (NB‐UVB)], and, recently, targeted phototherapy. After a literature search, we found only two studies using different targeted broad‐band UVB units for the treatment of vitiligo. Objective To evaluate the repigmentation response induced with broad‐band, UVB‐targeted phototherapy used as monotherapy in patients with vitiligo affecting less than 10% of the skin surface. Methods Twelve patients were recruited for treatment with 30 sessions of UVB‐targeted phototherapy administered twice weekly. The assessment of repigmentation was made from a comparison of baseline photographs with those after 30 sessions by two independent investigators. Morphometric analysis was performed using a computer program. Results Repigmentation with an average of 66.25% was obtained on lesions of the face, and of 31.5% on the neck, trunk, and genitalia. On the extremities, there was no repigmentation. Itching, a burning sensation, erythema, desquamation, and transitory hyperpigmentation were observed in some patients. Minimal blistering and ulceration were observed in one patient. Conclusion Targeted UVB phototherapy seems to be effective for the repigmentation of vitiligo in lesions located on the face, to a lesser degree on the trunk, and with no response in acral lesions; there were minimal adverse effects that did not require discontinuation of treatment.     

Cutaneous carcinoma and PUVA lentigines in Thai patients treated with oral PUVA

A total of 113 Thai patients who were treated with oral PUVA from 1979 to 1992 were examined for long-term cutaneous side effects of PUVA. Two psoriatic patients developed PUVA keratosis on non-sun-exposed areas. Both were skin type IV and had had phototherapy with UVB and sunlight previously. The total doses of UVA were 909 J/cm² and 242 J/cm² respectively. One psoriatic patient developed Bowen's disease. He had had a cumulative dose of UVA 2207 J/cm². He also had a past history of arsenic intake and phototherapy with UVB and sunlight. PUVA lentigines were seen in 58 patients (51.4%). It was associated with older age at starting PUVA, higher cumulative UVA dose and greater number of PUVA treatment. This study suggests that previous exposure to other risk factors is important for inducing skin cancer in populations with skin phototype III, IV and V treated with oral PUVA.     

Narrowband ultraviolet B phototherapy for patients with refractory uraemic pruritus: a randomized controlled trial

Background Pruritus is very common in uraemic patients, but the treatment remains challenging. Studies regarding narrowband ultraviolet B (NB‐UVB) phototherapy for uraemic pruritus are rare. Objectives To investigate whether or not NB‐UVB phototherapy is an effective treatment for uraemic pruritus. Methods We conducted a single‐blind, randomized, controlled trial for patients with refractory uraemic pruritus. The treatment group received NB‐UVB phototherapy three times per week for 6 weeks. The dose of NB‐UVB started from 210 mJ cm^?2 and was increased by 10% each time. The control group received time‐matched exposures to long‐wave UVA radiation. A visual analogue scale (VAS) score was evaluated weekly for pruritus intensity for 12 weeks. The characteristics of pruritus were also assessed by a questionnaire at baseline and after 6 weeks of phototherapy. Results Both the NB‐UVB and control groups had significant and comparable improvement in the pruritus intensity VAS scores during the period of phototherapy and follow‐up. Compared with the control group, the NB‐UVB group showed a significant improvement in the involved body surface area affected by pruritus (P = 0·006), but not in sleep quality. More detailed regression and estimating analysis revealed that the patients in the NB‐UVB group had lower pruritus intensity scores at week 6, week 10 and week 12. This may indicate a beneficial difference at certain time points, but the effect seems marginal. Conclusions NB‐UVB phototherapy does not show a significant effect in reducing pruritus intensity compared with a control group for refractory uraemic pruritus. Further studies are warranted.     

Medium-dose ultraviolet (UV) A1 vs. narrowband UVB phototherapy in atopic eczema: a randomized crossover study

Background Ultraviolet (UV) A1 and narrowband (NB)‐UVB have been reported to be effective treatments for atopic eczema (AE). Objectives We aimed to compare the efficacy of medium‐dose UVA1 and NB‐UVB mono‐phototherapy in patients with AE. Methods A randomized double‐blind controlled crossover trial (ClinicalTrials.gov Identifier: NCT00419406) was conducted in which patients with AE received a 6‐week course of both medium‐dose UVA1 and NB‐UVB. Clinical efficacy was assessed using the Six Area, Six Sign, Atopic Dermatitis (SASSAD) score and a visual analogue scale for pruritus. Assessment of health‐related quality of life was performed using the Skindex‐29. Total immunoglobulin E (IgE) and eosinophilic cationic protein (ECP) were evaluated at baseline and after each phototherapy course. Results Twenty‐eight patients who completed both UVA1 and NB‐UVB phototherapy courses on an intention‐to‐treat basis were analysed according to the crossover design. Both interventions were associated with significant clinical improvement but there was no significant difference between treatments with respect to the mean ± SD relative reduction (RR) of the clinical scores (SASSAD, 43·7 ± 31·4% vs. 39·4 ± 24·1%, P = 0·5; pruritus score, 16 ± 61·8% vs. 25·2 ± 30·5%, P = 0·5, respectively). There was no significant difference in the mean ± SD RR of the Skindex‐29 after UVA1 and NB‐UVB phototherapy (12·7 ± 18·8% vs. 16·5 ± 17·6%, P = 0·1). Changes in the total IgE and ECP levels following UVA1 and NB‐UVB did not differ significantly (P = 0·3 and P = 0·9, respectively). Conclusions A 6‐week course of NB‐UVB and UVA1 phototherapy of AE resulted in significant clinical improvement. With regard to efficacy and tolerability, both phototherapeutic modalities may be considered comparably good.     

Topical 8-methoxypsoralen enhances the therapeutic results of targeted narrowband ultraviolet B phototherapy for plaque-type psoriasis

Targeted broadband ultraviolet B (UVB) phototherapy as well as 308‐nm excimer laser have been reported to significantly improve or clear localized psoriatic plaques within 5 to 10 treatments when medium fluences [i.e. 4–6 multiples of minimal erythema doses (MED)] were used. Our study was conducted to determine the effects of different concentrations of topical 8‐methoxypsoralen (8‐MOP) cream when used in combination with targeted UV phototherapy with regard to number of treatments and cumulative UV doses to clear localized psoriasis. Ten evaluable patients with stable plaque‐type psoriasis completed the study. Three different concentrations of 8‐MOP creams (0.001%, 0.01% and 0.1%) were applied prior to irradiation with 4 MEDs of targeted narrowband UVB (NB‐UVB), whereas 0.001% 8‐MOP cream was used in conjunction with 5 J/cm² UVA. All irradiations took place once weekly for 12 weeks. Psoriasis severity index (PSI) score was used to evaluate the efficacy of the treatment. With area‐under‐the‐curve analysis, 0.1% 8‐MOP/NB‐UVB was superior to other modalities in reducing the PSI scores. The number of treatments and cumulative NB‐UVB doses necessary to achieve PSI‐95, a 95% reduction in the scores, was also lower in the 0.1% 8‐MOP/NB‐UVB group, although the differences were not statistically significant. We conclude that topical 8‐MOP cream enhances the therapeutic effects of targeted NB‐UVB phototherapy without significantly increasing the short‐term adverse effects.     

Photoadaptation of vitiliginous skin to targeted ultraviolet B phototherapy

BACKGROUND: Increasing doses of ultraviolet (UV) radiation are tolerated in patients with vitiligo, due to photoadaptation. In this pilot study, five patients with Fitzpatrick skin phototypes IV-VI with vitiligo received six treatments of targeted UVB phototherapy over a 3-week period. METHODS: To investigate photoadaptation, minimal erythema dose (MED) testing was conducted on treated and untreated vitiliginous and normal skin at baseline and after three and six treatments. One patient had unattainable MED values, and was hence excluded. RESULTS: Percent change in MED from before to after all treatments in vitiliginous skin ranged from 0% to 128%, with a mean of 48.8%. CONCLUSION: The pilot phase of this study suggests possible photoadaptation of vitiliginous skin of some patients to targeted UVB phototherapy.     

UVA1 phototherapy is effective in darker skin: a review of 101 patients of Fitzpatrick skin types I-V

Background  Studies suggest ultraviolet (UV) A1 phototherapy is efficacious and safe in treating a variety of skin disorders. However, most reports evaluating the benefits of UVA1 phototherapy have been from Europe, focusing on a predominantly Caucasian population. Darker skin types have been evaluated only sparingly; none the less, it is widely held that these patients respond poorly to UVA1 phototherapy due to increased pigmentation.
Objectives  We aim to compare efficacy (clinical improvement scores) of UVA1 phototherapy among Fitzpatrick skin types.
Methods  A retrospective analysis of 101 patients receiving UVA1 treatment at the University of Texas Southwestern Medical Center in Dallas, TX was performed. Data on Fitzpatrick skin type and cumulative UVA1 doses were collected. Clinical improvement scores based on body surface area, erythema, induration, sclerosis, pigmentation, and symptoms of pain or pruritus were obtained.
Results  In the population studied, with morphoea and scleroderma being the most frequent diagnoses, improvement scores from UVA1 phototherapy and mean cumulative UVA1 doses were not significantly different among the Fitzpatrick skin types evaluated. Furthermore, little or no correlation was found between improvement score and skin type.
Conclusions  Data indicate skin pigmentation as graded by Fitzpatrick skin type does not significantly influence the efficacy of UVA1 phototherapy. Thus, UVA1 should be considered as a therapeutic option in more darkly pigmented patients.     

NB‐UVB phototherapy for generalized granuloma annulare

Granuloma annulare (GA) is a benign, usually self‐limited, granulomatous skin disease of unknown etiology. The generalized form of the disease shows a more chronic, relapsing course, rare spontaneous resolution, and poorer response to therapy. Psoralen plus UVA phototherapy has been reported to be effective for GA. However, little is known regarding the efficacy of narrowband UVB phototherapy. Our goal was to determine the efficacy of NB‐UVB phototherapy in generalized GA. We carried out a retrospective study of patients with generalized GA treated with NB‐UVB phototherapy over a period of 3 years. On completion of treatment, outcome was assessed as complete response (complete clearance of the lesions), partial response (>50% clearance of the lesions), and poor response (<50% clinical response). Therapy was stopped if no improvement was seen after 20 treatments. Thirteen patients were included in the study. 54% of patients treated with NB‐UVB had a complete/partial response by the end of the treatment period. NB‐UVB phototherapy was well‐tolerated, with no serious adverse effects. NB‐UVB phototherapy is effective in a substantial portion of patients with generalized GA. To determine the true efficacy of this therapeutic modality, a prospective study comparing it to PUVA is warranted.     

Psoralen-ultraviolet A therapy vs. psoralen-ultraviolet B therapy in the treatment of plaque-type psoriasis: our experience with fitzpatrick skin type IV

BACKGROUND: Oral psoralen, when combined with UVB, shows an increased response in psoriasis. In this study, conventional psoralen-UVA (PUVA) therapy was compared with psoralen-UVB (PUVB) therapy in plaque-type psoriasis in patients with Fitzpatrick skin type IV. PATIENTS AND METHODS: Equal numbers of patients with stable, plaque-type psoriasis were treated with either PUVA (n = 22) or PUVB (n = 22), three times weekly until 90% clearance was achieved. A final evaluation was made 3 months later. RESULTS: The two groups showed no significant differences in terms of clearance of disease, mean number of exposures, or the average duration of therapy; however, the cumulative dose of UVB required for clearance was significantly lower than that of UVA. Both groups had a similar acute side-effects' profile. CONCLUSIONS: PUVB therapy is as effective as conventional PUVA in the treatment of stable, plaque-type psoriasis in patients with Fitzpatrick skin type IV. A significantly lower dose of UVB is required for clearance as compared with UVA.     

Could colorimetric method replace the individual minimal erythemal dose (MED) measurements in determining the initial dose of narrow‐band UVB treatment for psoriasis patients with skin phototype III–V?

Background Assessment of minimal erythemal dose (MED) for individual patients has been used to guide the narrowband Ultraviolet B (NB‐UVB) phototherapy, which sometimes causes discomfort and additional time. The L* value (the lightness of color in Commission Internationlale de l’Eclairge L*a*b* color scale) measured by colorimeter was shown to be useful for predicting sensitivity to NB‐UVB irradiation. Objective To compare the efficacy and safety of NB‐UVB phototherapy between 50% of MED and colorimetric L* value starting dose regimens for skin phototype III–V Korean patients with psoriasis. Method Twenty seven patients determined starting doses based on colorimetric L* value, and 27 patients based on 50% of MED. Since correlation analysis showed that L* value had the most significant association with MED compared with skin phototypes, a*, and b* values, we designated starting doses of L* value regimen as follows: 300 mJ/cm² (L* >66), 400 mJ/cm² (62 < L*≤66), and 500 mJ/cm² (L*≤62). Results There was no significant difference between two groups in clinical efficacy including response rate, mean number of sessions, duration of treatment, maximum dose and cumulative dose until achieving the state of near clearance. The proportion of adverse effects was not also significantly different. Conclusions NB‐UVB starting dose determination based on colorimetric L* value was comparable with conventional MED based regimen in efficacy and safety for skin phototype III–V patients. Since it provides much convenience and ease for both patients and physicians, colorimetric L* value could partly substitute the MED checking methods in NB‐UVB phototherapy.     

慢性光化性皮炎105例光试验研究

目的:总结日光模拟器对慢性光化性皮炎(CAD)患者进行光试验的结果与应用价值。方法:采用日光紫外线模拟器,对30名正常人和105例CAD患者进行长波紫外线(UVA)、中波紫外线(UVB)的最小红斑量(MED)测定。结果:在UVA波段,当剂量<40J/cm2时,30名正常人均无红斑反应,而105例CAD患者中63例出现不同程度的红斑反应(60%);在UVB波段,CAD患者的MED显著低于正常人(P=0.001)。结论:采用日光模拟器对CAD患者进行光试验,有助于对CAD的诊断。     

Incidence of skin cancers in 3867 patients treated with narrow-band ultraviolet B phototherapy

Background  Narrow‐band ultraviolet B (NB‐UVB) phototherapy is a widely used treatment. Psoralen‐UVA photochemotherapy (PUVA) increases skin cancer risk and some animal studies have raised the possibility of an increased risk with NB‐UVB. The risk of skin cancer in humans following treatment with NB‐UVB is unknown. Objectives  This current analysis forms part of an ongoing study ultimately aiming to define the long‐term carcinogenic risk of NB‐UVB treatment in humans. Methods  Details of all patients receiving NB‐UVB treatment until 31/12/2002 in Tayside, Scotland, were accessed from a treatment database and linked to the Scottish Cancer Registry. Indirect standardization was used to compare skin cancer incidence in the study population with age and sex matched cancer registry data for the Tayside population. We also assessed the effect of NB‐UVB exposure treatment numbers on the risk of developing skin cancer. Results  Of 4690 records reviewed, 4665 were suitable for analysis with 3886 records linked with the cancer registry and 3867 followed‐up for at least 6 months before 31/12/02 (the date at which cancer registration was deemed to be complete). The median number of NB‐UVB treatments was 29 with 352 patients receiving ≥ 100 treatments. The study gave 24 753 person‐years of follow up. First skin cancers recorded in study patients were 27 basal cell carcinomas (BCC), seven squamous cell carcinomas (SCC) and six melanomas. No association was found between NB‐UVB exposure alone (without PUVA) and any skin cancer. For NB‐UVB and PUVA treated patients there was an association with BCC, with 27 BCCs found compared with 14·1 expected in the matched population. Conclusion  We found no significant association between NB‐UVB treatment and BCC, SCC or melanoma. There was a small increase in BCCs amongst those also treated with PUVA. These reassuring results do not demonstrate the early increase in skin cancers that was found associated with PUVA treatment. However, cautious interpretation is required as the cohort contained relatively few patients who had a high treatment number and because the slow evolution of skin cancers may result in a delayed incidence peak. Ongoing risk assessment is therefore essential.     

Role of ultraviolet A in phototherapy for psoriasis

Multiple studies have demonstrated that the doses of ultraviolet A (UVA) (320-400 nm) achieved with ultraviolet sources presently used for phototherapy for psoriasis are inadequate to induce coal tar phototoxicity (as manifested by delayed erythema). Some centers still use a phototherapy protocol that combines UVA, ultraviolet B (UVB), and tar for the treatment of generalized psoriasis. We designed a bilateral comparison study to determine whether the addition of UVA to one side, in doses sufficient to induce an immediate burning or smarting sensation in tar-treated skin, would add to the beneficial effects of UVB. The psoriasis of ten of thirteen ambulatory patients cleared in a mean of 26.1 treatments. Despite a mean cumulative UVA dose of 130.8 joules/cm2, none of the thirteen patients showed a better response on the side that received additional UVA. A "nonaggressive" inpatient protocol was designed to maximize the chances of demonstrating a beneficial effect of UVA. The psoriasis of eight of twelve patients cleared in a mean of 21.0 treatments. Despite a mean cumulative UVA dose of 40.3 joules/cm2, the twelve patients showed no difference in clearing between sides. The threshold for smarting increased throughout the treatment and provided a convenient guide to the delivery of increasing doses of UVA. In doses sufficient to induce coal tar phototoxicity manifested by the smarting reaction, UVA does not add to the known benefits of UVB phototherapy.     

Remission period in psoriasis after multiple cycles of narrowband ultraviolet B phototherapy

The aim of this study was to investigate the duration of remission periods in psoriasis after narrowband ultraviolet B (NB‐UVB) phototherapy, especially during multiple cycles of treatment. We analyzed 63 patients (101 cases) demonstrating marked improvement after NB‐UVB phototherapy. The remission period was defined as the duration of time from the end of phototherapy until treatment using either phototherapy or systemic treatments was required again. It was found that an age of 60 years or older, history of systemic therapy within 6 months and three or more phototherapy cycles were significantly associated with shorter remission periods. Furthermore, multivariate analysis confirmed that three or more phototherapy cycles (odds ratio [OR], 4.0; 95% confidence interval [CI], 1.73–9.33; P = 0.001) and a history of systemic therapy (OR, 2.2; 95% CI, 1.27–3.95; P = 0.005) were independently associated with the shorter remission period. In conclusion, when planning NB‐UVB phototherapy for psoriatic patients who have undergone multiple phototherapy cycles, clinicians should consider the possibility of shorter remission periods.     

乌鲁木齐地区127例志愿者紫外线最小红斑量测定

目的 测定乌鲁木齐地区志愿者长波紫外线（UVA）、中波紫外线（UVB）的最小红斑量（MED）。方法 以SUV-1000型日光紫外线模拟器为光源,测定127例志愿者UVA-MED、UVB-MED。结果 Ⅲ型皮肤48例,UVA-MED中位数为38.10 J/cm2,UVB-MED中位数为31.80 mJ/cm2;Ⅳ型皮肤79例,UVA-MED中位数为59.16 J/cm2,UVB-MED中位数为48.00 mJ/cm2。男性UVA-MED中位数为59.16 mJ/cm2,女性为41.10 J/cm2;男性UVB-MED中位数为39.60 mJ/cm2,女性为35.55 mJ/cm2。男、女性Ⅲ型与Ⅳ型皮肤UVA-MED、UVB-MED中位数差异有统计学意义,Ⅲ型皮肤均显著低于Ⅳ型皮肤。男性UVA-MED显著高于女性（P < 0.05）,UVB-MED男女之间差异无统计学意义（P > 0.05）。Ⅲ型、Ⅳ型皮肤维族与汉族比较,UVA-MED和UVB-MED差异均无统计学意义（P值均 > 0.05）,男性、女性在不同年龄组间以及不同户外停留时间组之间差异也无统计学意义（P值均 > 0.05）。通过百分位数法确定UVA-MED的正常值 > 33.38 J/cm2,UVB-MED > 27.90 mJ/cm2。结论 皮肤光反应类型是决定MED的重要因素。