Comparison of turbo‐PUVA and conventional American‐style PUVA in the treatment of psoriatic patients

Background: Ultraviolet (UV)A protective properties of dihydroxyacetone (DHA) have been used as a topical UV‐resisting barrier to optimize psoralens and UVA (turbo‐PUVA). Starting doses and increments were based on the DHA diffuse reflectance spectroscopy‐derived protection factor. Objective: To evaluate the efficacy of turbo‐PUVA in psoriatic patients using a simpler method for determining starting doses and increments, in comparison to the conventional American‐style PUVA photochemotherapy. Methods: Thirty psoriasis patients (15 on American‐style PUVA and 15 on turbo‐PUVA) were evaluated, each receiving PUVA twice weekly. Starting UVA dose was determined according to skin phototype for the American‐style PUVA group and according to the patient's skin phototype × DHA SPF 3 in turbo‐PUVA group. UVA increments used were 0.5–1.5 J/cm² per treatment in American‐style PUVA and 25% of the previous dose in turbo‐PUVA. Results: Turbo‐PUVA group showed a significantly lower mean cumulative dose, a significantly higher psoriasis area and severity index score reduction, lesser mean number of treatment sessions, and less duration of treatment till remission (188.44±106.2 J/cm², 92.164±1.975%, 11.2±3.52 session, and 1.4±0.44 months, respectively) than conventional American‐style PUVA group (255.13±18.304 J/cm², 74.725±10.976%, 30±0.00 sessions, and 3.75±0.00 months, respectively). Conclusion: Turbo‐PUVA is more effective and time convenient for the treatment of psoriasis with less cumulative dose than the conventional American‐style PUVA.     

Erythemal and therapeutic response of psoriasis to PUVA using high-dose UVA

In PUVA treatment of psoriasis, clinical observation suggests that uninvolved skin is more susceptible to PUVA erythema than lesions of psoriasis. If this is the case, then the efficacy of PUVA treatment might be increased by using localized high-dose UVA restricted to lesional skin. We have therefore studied the erythemal and therapeutic response of psoriasis to PUVA using high-dose UVA and, for comparison, the erythemal response to UVB. In 14 patients, an area of psoriasis and adjacent uninvolved skin were exposed to a series of UVA doses (350 ± 30 nm, 1–16 J/cm²), using an irradiation monochromator. Six other patients were similarly phototested with a series of UVB doses (300 ± 5 nm, 20–112 mJ/cm²) to both uninvolved and lesional skin. Erythema was judged visually at 72 h for psoralen–UVA, and at 24 h for UVB, and measured using a scanning laser–Doppler velocimeter. In 10 patients, PUVA therapy using high-dose UVA was subsequently given to lesional skin (8–16 J/cm² twice weekly) in addition to conventional whole-body PUVA. For psoralen–UVA, the minimal phototoxic dose within psoriasis was increased by a factor of 4 compared with non-lesional skin (P < 0.01, Wilcoxon signed-rank test). For UVB, the minimal erythema dose within psoriasis was higher than that for non-lesional skin (medians > 112 and 28 respectively, P < 0.05). Laser–Doppler measurements confirmed that the reduced erythemal sensitivity was not due to masking of response by pre-existing increased blood flux within psoriasis. In six patients, the sites subsequently treated twice weekly with PUVA, using high-dose UVA, cleared faster (median number of treatments 3), but with a similar cumulative UVA dose, compared with adjacent lesional skin treated with conventional PUVA (median number of treatments 12). This study demonstrates that psoriasis may clear rapidly, without burning, using high-dose UVA. Availability of a suitable irradiation apparatus would allow rapid and effective PUVA treatment to be used for localized, resistant disease.     

Efficacy of topical PUVA soaks for palmoplantar dermatoses: an audit

Background: With a lack of evidence base for individual topical PUVA protocols, treatment is presently based on the consensus of current practice. This audit was designed to investigate the effectiveness of topical PUVA for palmoplantar dermatoses. Methods: Phototherapy notes were reviewed on all patients who received hand and/or foot PUVA 2002–2007 in the Northern Health and Social Care Trust (NHSCT), Northern Ireland. Results: Thirty patients met the inclusion criteria for the study. The mean number of treatments, maximum single UVA dose, and cumulative dose, were 18.4, 4.2 J/cm², and 48.3 J/cm², respectively. A positive response to treatment occurred in 51.3% of patients, which fell short of the 70% standard set. In a multivariate logistic regression analysis, number of treatments (P=0.04) and maximum single UVA dose (P=0.03) were the only variables associated with positive treatment outcome. The response was not influenced significantly by skin type, concurrent topical treatments, or cumulative UVA dose. Limitations to the study: Small patient numbers may have prevented the statistical significance of individual variables. Conclusions: UV dose increments should be clearly defined to avoid excess caution at the expense of an adequate patient response, and a minimum of 20 treatments administered to all patients, if tolerated.     

Combination therapy of oral methoxypsoralen: photochemotherapy (PUVA) and an aromatic retinoid (etretinate, tigason) in the treatment of psoriasis

RePUVA is the combination of an oral aromatic retinoid, etretinate, with oral photochemotherapy, PUVA. This combination therapy has the advantage of faster clearance with fewer side effects. In Middle Road Hospital, we treated 29 patients with extensive psoriasis (more than 30% involvement) with a total 32 RePUVA treatments. There was complete clearance in 69% of patients with an average of 19 irradiations and an average total ultraviolet A (UVA) dose of 183 J/cm². This compared well with standard PUVA which needed 25 radiations and a total UVA dose of 346 J/cm². The main side effects were cheilitis, exfoliation of skin and pruritus. Biochemically, 41% of the patients showed elevations of serum triglyceride.     

Cumulative UV radiation dose and outcome in clinical practice: effectiveness of trioxsalen bath PUVA with minimal UVA exposure

BACKGROUND: The cumulative artificial ultraviolet (UV) exposure dose of dermatological patients was prospectively monitored in clinical conditions for a total of 2 years (August 1997 - July 1999). We focused on whole body UV treatments, i.e. the trioxsalen (TMP) bath PUVA, the broad-band UVB, and the UVA plus UVB phototherapy. METHODS: Irradiance of the UV devices was calibrated with a spectroradiometer. The cumulative UV doses received by the patients were recorded. A visual analog scale scoring system (VAS) was employed to assess the improvement of various skin conditions at the end of the treatment course. RESULTS: The analysis included 265 patients (141 females and 124 males) and a total of 311 UV treatment courses. Treatments consisted of 86 courses of TMP bath PUVA for psoriasis with a mean cumulative UVA dose of 3.54 J/cm2 and an improvement rate of 89%. For other conditions, 30 courses were needed, with a cumulative UVA dose of 1.47 J/cm2 and an improvement rate of 76%. Altogether, 47 UVB courses were undertaken for psoriasis, and the mean cumulative unweighted UV dose was 2.20 J/cm2, equivalent to 85 standard erythema doses (SED), and an improvement rate of 85%. A total of 25 UVB courses was used for other skin conditions with a mean UV dose of 1.05 J/ cm2, equivalent to 40 SED, and an improvement rate of 71%. A total of 123 courses of UVA plus UVB phototherapy were completed, resulting in a mean cumulative dose of 73.01 J/cm2 for UVA and 0.75 J/cm2 for the unweighted UVB, equivalent to 29 SED. The VAS improvement rate was 85%. CONCLUSION: The exceptionally low mean cumulative UVA dose in the TMP bath PUVA, taken together with the previous report showing no increase in the risk of squamous cell carcinoma or cutaneous malignant melanoma after TMP bath PUVA, suggests that TMP bath PUVA is an effective and safe therapeutic option.     

Combination of photochemotherapy (PUVA) and ultraviolet B (UVB) in the treatment of psoriasis vulgaris

Nineteen patients with psoriasis vulgaris were treated with a combination of psoralen-ultraviolet A (PUVA) and ultraviolet B (UVB) on the right side of their bodies and with PUVA therapy alone on the left side. Herein is an analysis of the results. There were no significant differences in the mean number of treatments, the mean UVA dose at clearing, or the mean cumulative UVA dose between the PUVA-UVB side and the PUVA side. However, in 4 cases, the PUVA-UVB side cleared more rapidly than the PUVA side. Interestingly, patients who received PUVA-UVB on one side and PUVA on the other required fewer treatments, a lower ultraviolet (UV) dose at clearing, and a lower cumulative UV dose than did patients who were treated with only PUVA monotherapy or UVB monotherapy, following the same protocol. This combined method may be useful in the treatment of chronic psoriatic patients, because of rapid clearing and a marked reduction in the total cumulative UV radiation. However, further follow-up studies are indicated due to the long-term side effects of combined UV radiation.     

Effects of in vitro PUVA treatment on adenylate cyclase responses of epidermis

We investigated the effect of 8-methoxypsoralen (8-MOP) plus long wave ultraviolet irradiation (PUVA) on the pig skin epidermal cyclic AMP (cAMP) system. Following PUVA treatment in vitro, pig skin squares were incubated in RPMI 1640 medium, and the cAMP accumulation by various adenylate cyclase stimulators was determined. A significant increase of the beta-adrenergic adenylate cyclase response was observed as early as 6-h following PUVA treatment; the maximal effect was reached at 24-h and lasted at least for 72-h. This augmentation effect of PUVA treatment was potentiated by increasing the 8-MOP concentration (0.5–160 μg/ml) and UVA irradiation dose (0.05–1.4 J/cm²). At higher irradiation doses (2.1–2.8 J/cm²), the beta-adrenergic augmentation effect was less marked. There were no significant differences in the adenosine-and histamine-adenylate cyclase response up to 1.4 J/cm² irradiation; however, the latter was decreased at a higher irradiation dose (2.8 J/cm²). Although UVA irradiation alone had no effect on the beta-adrenergic response, 8-MOP treatment alone increased this receptor response at higher concentrations; this effect was much weaker than that induced by PUVA treatment. Cyclic AMP phosphodiesterase activities were not affected by PUVA treatment. These results indicate that epidermal adenylate cyclase response is affected by in vitro PUVA treatment.     

Treatment of persistent severe atopic dermatitis in 113 Japanese patients with oral psoralen photo-chemotherapy

Oral administration of psoralen and whole body exposure to UVA (oral PUVA) has been used for the treatment of 113 patients with severe atopic dermatitis (AD). 8-Methoxypsoralen (8-MOP) was given at a dose of 0.5-0.6 mg/kg two hours prior to UVA (3-8 J/cm2) irradiation. Patients were treated three times a week while hospitalized. Other medications which had been given before PUVA therapy were permitted. At four and eight weeks after PUVA therapy, the severity score of AD had decreased by 51% and 80%, and the cumulative doses of UVA were 51.2 J/cm2 and 115.3 J/cm2, respectively. The amounts and strength of topical cortico-steroids were decreased during PUVA therapy. No adverse effects that required discontinuation of the PUVA therapy were observed. After discharge, maintenance therapy with UVB phototherapy and/or conventional treatment of AD kept the patients in remission in the outpatient clinic. The QOL of patients was greatly improved. Photochemotherapy with oral 8-MOP can be indicated in patients with severe, widespread AD, especially if standard therapy fails. This is the first report of oral PUVA therapy in a large series of Japanese patients with AD.     

Evaluation of narrow band ultraviolet B phototherapy in the treatment of chronic actinic dermatitis in Chinese patients

Few studies have been conducted in chronic actinic dermatitis (CAD) treated with narrowband ultraviolet B (NB UVB) phototherapy, especially in Asian patients. We aim to evaluate the efficacy and safety of NB UVB phototherapy in Chinese patients with CAD. 19 CAD patients of Fitzpatrick skin phototype IV received NB UVB phototherapy in spring and treatments were given 3 times weekly with incremental dose and maintenance therapy was given twice weekly for 3–4 weeks. The mean initial, endpoint, and cumulative dose of NB UVB was 0.08, 0.33, and 6.0 J/cm², respectively. Patients totally received 27 times of treatments in average. 87.5% of previously ultraviolet B（UVB） sensitive patients and 75% of previously ultraviolet A（UVA） sensitive patients had normal or improved MED after phototherapy. The percentage of patients returned to normal UVB phototesting was higher than that of patients returned to normal UVA phototesting (68.8% vs. 37.5%). The mean 1‐week DLQI and the need for using immunosuppressive agents and antihistamines were significantly reduced after treatment (p < .01 or p < .05). In conclusion, prophylactic NB UVB phototherapy is effective and safe in treatment of CAD in Chinese patients with Fitzpatrick skin phototype IV.     

Successful Treatment of Scleroderma with PUVA Therapy

PUVA therapy was carried out on four patients with scleroderma; three of them had cutaneous manifestations of progressive systemic sclerosis and one other exhibited generalized morphea. PUVA therapy was given with daily doses of 0.25 J/cm² or 0.4 J/cm² for 3–8 weeks, resulting in total doses between 3.5 J/cm² and 9.6 J/cm². All four patients responded well to this treatment; improvements of hand closure, skin sclerosis index, and flexion of fingers or knee joints were obtained. Thus, PUVA appeared to be beneficial for treating scleroderma.     

Topical PUVA Therapy for Chronic Hand Eczema

Seventeen patients with persistent chronic hand eczema were treated with topical 0.1% 8-methoxypsoralen and UVA (PUVA) for 8 weeks. Significant improvement was achieved in 5 cases (29%), moderate improvement in 9 (53%), and little improvement in 3 (18%). The mean number of PUVA treatments was 22.2, and the mean total UVA dose was 63.5 J/cm². There was no association between clinical response and duration of hand eczema, positive patch test reaction, or atopic status. Since topical PUVA has no risk of systemic side effects, it should be considered as an alternative treatment for patients with chronic hand eczema who are resistant to other topical medications.     

A trial of accelerated PUVA in psoriasis

Ten psoriatic patients were treated with an accelerated PUVA regimen. Nine patients cleared in an average of 13·7 treatments (range 4-24) after an average total UVA dose of 83 J/cm² (range 18-186). One patient had to withdraw due to pruritus and burning and six others had burning problems. The high incidence of burning may limit the routine use of this irradiation regimen.     

Narrowband UVB and cream psoralen-UVA combination therapy for plaque-type psoriasis

BACKGROUND: Psoralen-UVA (PUVA) and narrowband UVB (311-nm) therapy are considered to be first-line phototherapies for patients with moderate to severe psoriasis. To reduce side effects as a result of systemic resorption of psoralens, topical PUVA therapies have been developed and proven to be effective in the treatment of psoriasis. OBJECTIVE: We sought to evaluate the combination therapy of narrowband UVB plus cream PUVA on selected psoriatic plaques compared with narrowband UVB or cream PUVA alone. METHODS: A total of 30 patients (Psoriasis Area and Severity Index score of 8-15) were included in the randomized study. The combination therapy consisting of narrowband UVB whole-body irradiation followed by cream PUVA therapy for selected psoriatic plaques was evaluated in 10 patients with chronic plaque-stage psoriasis. For comparison, the therapeutic efficacy, number of treatments, and cumulative UV doses until remission (Psoriasis Area and Severity Index score < 4) of cream PUVA therapy or narrowband UVB alone was determined in 10 patients, respectively. RESULTS: Both monotherapies induced clearance of psoriatic lesions in all patients within 5 to 7 weeks. Mean number of treatments for cream PUVA was 24 +/- 5; for narrowband UVB was 21 +/- 3. The mean cumulative UVA dose was 45.0 +/- 16.3 J/cm(2) and the mean cumulative UVB dose was 17.1 +/- 4.1 J/cm(2). Combination therapy resulted in complete clearance of lesions in all patients after 3 to 4 weeks. Mean number of treatment was 14 +/- 2, mean cumulative UVA dose was 18.7 +/- 4.7 J/cm(2), and mean cumulative UVB dose was 8.2 +/- 3.3 J/cm(2). The number of treatments (P <.001, analysis of variance), UVA dose (P <.001, t test), and UVB dose (P <.001, t test) were significantly reduced compared with both monotherapies. CONCLUSIONS: Our results indicate that a combination therapy of narrowband UVB plus cream PUVA appears to have a significantly higher efficacy compared with either monotherapy. The cumulative UV doses were significantly lower in the combination therapy. We conclude that cream PUVA can be used in addition to narrowband UVB for areas that tend to clear less quickly than the rest of the body.     

Large increments in psoralen-ultraviolet A (PUVA) therapy are unsuitable for fair-skinned individuals with psoriasis

The ideal psoralen-ultraviolet A (PUVA) regimen for chronic plaque psoriasis has yet to be established. There are four components to a PUVA regimen: the dose of psoralen, the starting dose of UVA, the frequency of treatment and the incremental UVA dose protocol. Recent studies have been directed at trying to optimize the efficacy of PUVA while minimizing acute side-effects and the risk of cutaneous carcinogenesis, believed to be independently related to the cumulative dose of UVA and the total number of treatments. The British Photodermatology Group recommends two twice-weekly PUVA regimens: one starts with 50% of the minimal phototoxic dose (MPD) and uses weekly increments of 40%, 30%, 25%, 20%, 15%, 10% and 5% of the previous dose to a maximum of 14.5 J/cm2; the other starts with a fixed dose based on skin type and uses weekly dose increments of 40%, decreasing to 20% once erythema develops. We undertook a prospective randomized controlled trial comparing these regimens in 85 Irish patients. The clearance rate with the MPD regimen was lower than with the skin type regimen, 67.5% vs. 95% (P < 0.05). The reasons for treatment failure were grade 3 erythema and severe PUVA itch. There was a trend suggesting that patients with skin types I and II, but not skin type III, required a higher cumulative UVA dose and fewer exposures to clear with the MPD regimen than the skin type regimen, although this did not reach statistical significance. Grades 2 or 3 erythema were very common in both treatment groups (52. 5% of the skin type group and 45% of the MPD group). This is the third study to suggest that patients with skin types I and II receive a higher total UVA dose when the starting dose is 50-70% of the MPD (rather than 0.5 J/cm2 for skin type I and 1.0 J/cm2 for skin type II) and when large dose increments are used. We suggest that smaller dose increments should be used in patients with skin types I and II.     

In vivo PUVA and UVB sensitivity of various human epidermal Langerhans cell markers (ATPase, HLA-DR and T6)—Dose-response and time-sequence studies

To form a comprehensive view of the UV-sensitivity of human epidermal Langerhans cells (LC), the time-sequence and close response effects of single doses of UVB or 8-methoxypsoralen plus UVA (PUVA) radiation on three different LC surface markers were studied with histochemical and immunohistochemical staining. An increasing PUVA dose from 1 to 10 J/cm² caused an almost linear decrease in the surface enzyme (ATPase) positive LC count, whereas the cell surface antigens (HLA-DR and T6) were rather more resistant, up to a PUVA dose of 5 J/cm². A single dose of 5 J/cm² of PUVA induced an LC depletion that was similar during the 21 days of observation, irrespective of whether the cells were visualized with ATPase staining or with monoclonal antibodies against the cell surface antigens HLA-DR or T6. In each case, the nadir was reached 14 days after irradiation; the average residual LC count was then 57%. The cell counts 21 days after PUVA irradiation were still only approximately 74% of the nontreated skin counts. Langerhans cell depletion induced by an erythemagenic dose of UVB irradiation was swifter and more pronounced than that induced by 5 J/cm² of PUVA but, again, a similar time schedule was recorded with ATPase, HLA-DR and T6 staining.     

Morphological changes in the proximal area of the rat's hair follicle during early catagen

Summary In human adult volunteers, oral 8-methoxypsoralen and UVA (PUVA) caused an almost linear dose-response effect in depleting adenosine triphosphatase positive epidermal Langerhans cells (LC) when irradiations of 1–5 J/cm² were used. A higher dose did not appreciably augment the LC depleting effect although the intensity of the PUVA-induced skin inflammation increased. After a single PUVA dose of 5 J/cm², a nadir in LC density was achieved on day 8 after irradiation, with a decrease from the starting mean count of 704 ± 58 cells/mm² to 195 ± 173 cells/mm². On day 15 after irradiation, the LC count was still low (261±249 cells/mm²). In comparison, a single erythematogenic irradiation with a medium-pressure mercury lamp emitting mainly UVB caused an LC depletion which was less intensive, peaked earlier and was almost completely restored by day 15. With both modalities morphological changes were induced in the LC, manifested initially as a shortening of the dendritic processes and later as cell enlargement and dendrite elongation.     

DNA repair elicited by UVB during PUVA therapy for psoriasis

Summary The skin of patients receiving psoralen and UVA (PUVA) therapy for psoriasis is exposed to trace amounts of UVB radiation emitted by PUVA irradiators in addition to UVA. DNA repair activity was measured using autoradiography in the uninvolved skin of PUVA-treated patients in order to determine whether 8-methoxypsoralen (8-MOP) plus UVA elicits repair, inhibits the skin repair response to UVB, or protects epidermal-cell DNA from UVB damage by promoting a tan. Epidermal-DNA repair activity was observed in 27 out of 37 patients following the first PUVA treatment. Phototesting with multiples of the initial UV dose elicited a linear increase in repair activity. Glass-filtered radiation failed to stimulate repair, indicating that the reaction was due to UVB, not to 8-MOP plus UVA. The same amount of repair activity was observed in the skin of patients irradiated either before or after 8-MOP ingestion, demonstrating that the drug did not interfere with the response of the skin to UVB. At clearing, however, the repair activity was never greater than that elicited at the initial treatment and was often undetectable despite a tenfold increase in UV exposure. It is proposed that DNA damage should be measured to determine whether epidermal cells are entirely protected from UVB radiation at the completion of therapy.     

The effectiveness of PUVA treatment in severe psoriasis is significantly increased by additional UV 308-nm excimer laser sessions

In most cases, patients with moderate to severe psoriasis are treated with narrow-band UVB phototherapy or with psoralen UVA (PUVA-) photochemotherapy. This UV-radiation is given to the whole skin, including unaffected skin. Normally, these two PUVA- and UVB-radiation procedures cannot be combined on account of the phototherapeutic side-effects on unaffected skin. The 308-nm excimer laser has been shown to be safe and effective in the treatment of localized mild-to-moderate plaque-type psoriasis whilst sparing healthy skin. Our aim was to compare the therapeutic response to PUVA plus up to 4 UVB308-nm radiations and PUVA monotherapy in patients with moderate-severe plaque-type psoriasis. 272 hospitalized adult patients were enrolled on this prospective random study. 256 patients completed the full course of treatment. PUVA treatment was given 4 times weekly to all patients. 123 patients received PUVA as a monotherapy. During the first two weeks, 149 patients were additionally treated up to four times with 308-nm excimer-derived UVB on the affected skin and treatment was evaluated for its efficacy, duration, number of times necessary for complete (CR) or partial remission (PASI reduction > 90 or > 50%, respectively), cumulative light dose, side effects of therapy and duration of remission after therapy. Statistically, there is no significant difference when comparing the efficacy of PUVA (CR 67.3%) and PUVA plus excimer (CR 63.6%). On average, patients treated by the combination method went into remission in half the treatment time (15 +/- 6 versus 27 +/- 7 days) and with half the cumulative UVA dose (22.9 +/- 5.8 versus 53.2 +/- 26.3), p < 0.05. In conclusion, skin heals considerably quicker when treated with a combination of photochemotherapy and a short course of UVB 308 nm laser treatment applied directly to the affected skin, resulting in a shorter hospital stay and quicker rehabilitation of patients with moderate-severe psoriasis.     

Effectiveness of medium-dose ultraviolet A1 phototherapy in localized scleroderma

Background Recently, ultraviolet (UV) A1 phototherapy has been suggested as an effective treatment for localized scleroderma (LS); however, the optimal dose of UVA1 still has not been determined. Objective We aimed to evaluate the therapeutic effectiveness of medium‐dose (30 J/cm²) UVA1 phototherapy and to show that 13 MHz ultrasound is a valuable tool for assessing the results of UVA1 phototherapy in LS. Methods Thirty‐five patients with LS were treated with medium‐dose (30 J/cm²) UVA1. In total, 30–45 treatments and 900–1350 J/cm² cumulative UVA1 doses were evaluated by clinical scoring in all patients. In 14 patients, skin thickness was also determined by 13 MHz ultrasound examination. Results In all patients, medium‐dose UVA1 therapy softened sclerotic plaques, and marked clinical improvement was observed in 29 of 35 (82. 85%) patients. Ultrasound measurements showed that skin thickness was significantly reduced. No side effects were observed during or after treatment. Conclusion Medium‐dose UVA1 phototherapy is a highly effective, safe, and well‐tolerated therapeutic modality for treatment of all types of LS. A 13 MHz ultrasound probe may be used for evaluating UVA1 phototherapy results.     

Successful ultraviolet A1 phototherapy in the treatment of localized scleroderma: a retrospective and prospective study

Background Ultraviolet (UV) A1 phototherapy is an effective anti‐inflammatory treatment modality that influences fibroblast functions. Objectives To document the effects of UVA1 treatment in patients with localized scleroderma (LS) in a retrospective study (at least 6 months after UVA1 treatment) and in a prospective study before and immediately after medium‐dose UVA1 irradiation. Methods In total, 30 patients (retrospective study n = 17, prospective study n = 13) with LS receiving UVA1 phototherapy five times weekly (for 3–6 weeks) were investigated. Improvement was documented using standardized questionnaires and clinical evaluation (using modified Rodnan skin score, Cutometer and 7·5‐MHz ultrasound measurements). Levels of collagen I and collagen III metabolites were measured in serum and urine. Results In the retrospective study, medium‐dose UVA1 phototherapy had been performed 6 months–3 years earlier (cumulative dose 750–1400 J cm^?2; mean ± SD number of irradiations 19·3 ± 3·8). Fourteen of 17 patients (82%) reported an improvement in symptoms following UVA1 therapy. In the prospective study, skin elasticity increased in 77% of the patients following medium‐dose UVA1 phototherapy (cumulative dose 750–1250 J cm^?2; mean ± SD number of irradiations 20·8 ± 4·0). 7·5‐MHz ultrasound measurements showed a mean reduction of lesional skin thickness of 13% compared with skin thickness before UVA1 phototherapy. The ratio of deoxypyridinoline to creatinine was significantly elevated in about two‐thirds of the patients. Conclusions This open study showed a positive short‐ and long‐term efficacy of UVA1 phototherapy in patients with LS, with a reduction in sclerotic plaques, an increase in skin elasticity and a reduction of lesional skin thickness. UVA1 phototherapy had a significant effect on collagen metabolism. UVA1 phototherapy can be regarded as a safe treatment modality for patients with LS.