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.     

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.     

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.     

Combination of methoxsalen and ultraviolet B (UVB) versus UVB radiation alone in treatment of psoriasis: a bilateral comparison study

A bilateral comparison study of the therapeutic effects of broad-band ultraviolet (UVB) (FS-40 Sunlamp bulbs) radiation versus UVB radiation plus methoxsalen was conducted in patients with psoriasis. Ten patients were given up to 30 exposures to the two treatments on paired, similarly affected limbs. There was no detectable difference in the response of limbs treated with UVB plus methoxsalen versus UVB phototherapy alone although all patients did show a therapeutic response. Other areas of the body treated with methoxsalen and broad-band UVA radiation (PUVA bulbs) responded more rapidly and to a greater extent than areas exposed to UVB radiation.     

Effect of psoralens and ultraviolet radiation on murine dendritic epidermal cells

Monofunctional psoralens produce less phototoxicity than bifunctional psoralens after ultraviolet A (UVA) irradiation. We investigated the effect of repetitive treatments with angelicin (isopsoralen), a monofunctional psoralen, plus UVA radiation (IPUVA) on the number and morphology of dendritic epidermal cells (dEC). This effect was compared with that of 8-methoxypsoralen plus UVA radiation (PUVA), UVA alone, and UVB radiation. C3H/HeN mice were treated topically with the drugs three times/wk for 4 consecutive wk; followed each time by 1 or 2.5 J/cm2 of UVA radiation. Other groups of mice were treated with the drugs alone, UVA alone, or 0.81 J/cm2 of UVB. Epidermal sheets were stained for ATPase, Ia, and Thy-1 markers. Mice treated with PUVA and UVB exhibited severe phototoxicity, whereas no overt phototoxicity was observed in mice treated with IPUVA, UVA alone, or the drugs alone. Early during the PUVA and UVA treatments the ATPase marker was lost from dEC, followed by loss of the Ia marker; the Ia marker was lost before the ATPase marker from dEC in animals treated with IPUVA. At the end of the treatment, however, nearly total depletion of ATPase+, Ia+, and Thy-1+ dEC was observed in mice treated with PUVA and IPUVA. UVB radiation caused rapid depletion of Thy-1+ dEC as well as ATPase+ and Ia+ cells. During treatments with IPUVA, PUVA, UVA, and UVB, the Langerhans cells became rounded and lost their dendrites. These changes were quantitated by image analysis. We conclude that alterations of cutaneous immune cells can occur in the absence of overt phototoxicity, and that monofunctional and bifunctional psoralens plus low dose of UVA radiation may have different effects on dEC markers.     

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.     

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.     

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.     

A comparison of psoralen plus ultraviolet A (PUVA) monotherapy,tacalcitol plus PUVA and tazarotene plus PUVA in patients with chronic plaque-type psoriasis

BACKGROUND: Numerous studies have shown that the additional administration of topical or systemic antipsoriatic agents might serve as an effective means to increase the efficacy of photochemotherapy [psoralen plus ultraviolet (UV) A (PUVA)] for psoriasis. OBJECTIVES: To compare the therapeutic response to tacalcitol plus PUVA, tazarotene plus PUVA and PUVA monotherapy in patients with chronic plaque-type psoriasis. In addition, we also assessed the duration of remission induced by each regimen and the tolerability of the two combination treatments. METHODS: Thirty-one patients with chronic plaque-type psoriasis were included in this observer-blinded, intrapatient comparison trial. PUVA treatment was given four times weekly. Additionally, tacalcitol ointment and 0.1% tazarotene gel were applied separately on two target areas once daily in the evening. At the onset of therapy and every 2 weeks thereafter the response to treatment was determined by the Psoriasis Severity Index score, which assesses the degree of erythema, infiltration and scaling of the psoriatic lesions. After complete or near complete clearing patients were followed-up until relapse. RESULTS: Twenty-four patients completed the study. The treatment requirements to induce complete or near complete clearing were significantly lower for both combination treatments than for PUVA monotherapy (P < 0.01). The median cumulative UVA dose and number of exposures were 30.6 J cm-2 (95% confidence interval, CI 22.5-71.2) and 14 (95% CI 11-16) for tacalcitol plus PUVA, 32.3 J cm-2 (95% CI 22.5-73.8) and 14 (95% CI 11-19) for tazarotene plus PUVA, and 37.0 J cm-2 (95% CI 29.5-83.9) and 16 (95% CI 14-22) for PUVA monotherapy. No difference between the three regimens was observed with regard to duration of remission. Adverse reactions occurred more often with 0.1% tazarotene than with tacalcitol but were in general mild and completely reversible upon using a lower concentration of 0.05% tazarotene. CONCLUSIONS: Tacalcitol ointment and tazarotene gel are both comparably effective in improving the therapeutic result of PUVA therapy in patients with chronic plaque-type psoriasis. Besides accelerating the treatment response, both agents, by virtue of their UVA dose-sparing effect, might also help to reduce possible long-term hazards of PUVA treatment.     

Incidence of skin cancer in Japanese psoriatic patients treated with either methoxsalen phototherapy, Goeckerman regimen, or both therapies: A 10-year follow-up study

To determine the long-term cutaneous side effects of methoxsalen phototherapy (PUVA) and Goeckerman regimen, a total of 151 Japanese psoriatic patients treated with PUVA, Goeckerman regimen, or both therapies in our department from 1976 to 1986 were evaluated for skin cancers. Sixty-seven patients had been treated with PUVA, 43 with Goeckerman regimen, and 41 with both therapies. One patient alone (62-year-old man) developed squamous cell carcinoma on the leg with cumulative ultraviolet A (UVA) dose of only 51 joules/cm2, he had a history of treatment with superficial x-ray therapy to this area 30 years prior to PUVA. The cancer was detected after 1.4 years of PUVA treatment. However, other patients at follow-up, even those who had received a cumulative dose of UVA of more than 1000 joules/cm2, had no skin cancer after more than 2 years. This report in Japanese patients confirms that only previous exposure to other risk factors such as ionizing radiation appears to be a most important factor for skin cancer formation in PUVA-treated Japanese patients.     

Hand and foot PUVA soaks: An audit of the Massachusetts General Hospital''s experience from 1994 to 1998

Palmoplantar psoriasis and eczema can be chronic recalcitrant dermatoses. Oral psoralen plus ultraviolet A (PUVA) has proven effective for these, but has a number of unwanted side effects. Previous studies have shown that regional PUVA therapy using the 8-methoxypsoralen (8-MOP) soak method followed by immediate UVA irradiation is also beneficial and well tolerated. The purpose of this audit was to determine the efficacy of hand and foot PUVA soaks by reviewing the experience of the Massachusetts General Hospital's Phototherapy Unit with this treatment modality. Phototherapy records of all patients who underwent hand and foot PUVA soaks from 1994 to 1998 were reviewed. Details regarding the treatment procedure, patient compliance, patient response and incidence of side effects were noted and summarized. Of the 56 patients who underwent at least 20 treatments, 29% had excellent response, 42% had minimal to moderate response, and 29% had poor response. The average number of treatments to induce clearing was 41. The average maximum treatment dose at clearing was 5.85 J/cm2, while the average cumulative dose to achieve clearing was 267.17 J/cm2. 8-MOP PUVA soak therapy is quite useful for chronic hand and foot dermatoses. Patient compliance must be emphasized to obtain favorable results.     

Randomized half-side comparison of narrowband UVB and trimethylpsoralen bath plus UVA treatments for psoriasis

The efficacy of trimethylpsoralen bath PUVA and UVB TL01 were compared in chronic plaque psoriasis. Patients were randomly assigned to receive UVB TL01 on one side and bath PUVA on the contra-lateral side. Altogether 17 patients received treatments and 15 completed the trial. The decrease in the PASI score was greater with UVB TL01 than PUVA. At the end of the treatment period, the difference was highly significant (p < 0.001). The difference was already significant at week 3 (p = 0.014). The relative median decrease in the PASI score was 77% (24-100%) with UVB and 45% (8-100%) with PUVA. The median cumulative UVB dose was 39.92 (range 13.95-81.56) J/cm2 and the corresponding UVA dose was 8.06 (range 3.31-12.51) J/cm2. All patients relapsed within 4 months. Narrowband UVB improved psoriasis clinically and statistically more efficiently than trimethylpsoralen bath PUVA, and UVB was better tolerated.     

Narrow band Ultraviolet B 311 nm in the treatment of vitiligo: two right-left comparison studies

AIM: Evaluation of narrow band ultraviolet B (NB UVB 311 nm) in the treatment of vitiligo by two independent studies. The first study compared NB UVB with a well-established therapeutic modality, psoralen ultraviolet A (PUVA), and the second study was conducted to find out whether psoralen might add to its efficacy. METHODS: In the first study, 15 patients were exposed on the left half of their body to UVB 311 nm and then exposed on their right half to UVA after ingestion of psoralen. In the second study, 20 patients were exposed to UVB 311 nm on the left side of the body, followed by ingestion of psoralen and exposure to NB UVB 311 nm 90 min later to the right side of the body. In both studies, while exposing one side, the other was protected by an UV-proof gown. Thus two right-left comparative studies were carried out simultaneously, namely: UVB 311 nm vs. PUVA and UVB 311 nm vs. PUVB 311 nm. RESULTS: In the first study, comparison of PUVA and NB UVB 311 nm showed no difference either in the degree of response or in the incidence of complications. In the second study, comparison of PUVB and UVB showed equal clinical improvement on both sides. The cumulative dose needed to achieve the same response on the PUVB side was lower than that on the UVB side, but the difference was not statistically significant. The incidence of phototoxic reactions was significantly higher on the PUVB treated body half. CONCLUSION: NB UVB 311 nm has similar repigmentary effects as PUVA. The addition of psoralen does not increase its efficacy.     

Prophylactic PUVA and UVB therapy in polymorphic light eruption—a controlled trial

A double-blind controlled trial of low-dose prophylactic oral psoralen photochemotherapy (PUVA) and ultraviolet-B (UVB) irradiation therapy was undertaken from April to September 1983 in 42 patients with polymorphic light eruption (PLE). Patients were randomly allocated to three groups, PUVA with oral 8-methoxypsoralen (8-MOP), UVB with oral placebo, and control low-dose UVA with oral placebo. The initial dose given to each active treatment group was a third of the predetermined minimal phototoxic or erythema dose, followed three times weekly for 6 weeks by doses incremented by an eighth on each occasion in the PUVA group and by a seventh in the UVB group. Ultraviolet radiation exposure was monitored throughout with polysulphone film lapel badges. Patients recorded their symptoms on a visual analogue scale. Symptoms of rash and itch in patients treated with PUVA and UVB were significantly less affected by increasing exposure to ultraviolet radiation than were these symptoms in control patients.     

Antinuclear antibodies in mice induced by long wave ultraviolet radiation (UVA)

PUVA therapy has been reported to induce antinuclear antibodies (ANA). The generation of ANA following ultraviolet irradiation was studied experimentally in albino mice. When treated with long wave ultraviolet radiation (UVA) from blacklight fluorescent tubes a significant number of animals developed positive ANA titres, whereas no change was noted in groups, treated with PUVA, 8-methoxypsoralen only or medium wave ultraviolet irradiation (UVB) respectively. The tendency for UVA-irradiated mice to develop ANA was stronger when higher ANA titres were compared. UVA induces ANA in mice, and PUVA-induced ANA may be due to the UVA component of this therapy.     

Narrowband UVB phototherapy for early-stage mycosis fungoides: evaluation of clinical and histopathological changes

Background Early‐stage (IA, IB, IIA) mycosis fungoides (MF) has long been treated with various agents including topical potent steroids, nitrogen mustard, carmustine, oral psoralen plus UVA (PUVA), broadband UVB, electron‐beam radiotherapy, interferon‐α and retinoids. However, each of these modalities is associated with various side‐effects. Narrowband UVB (NB‐UVB) therapy has the same effect but is safer to use than the other methods. Objective Our purpose in this prospective study was to determine the effects of NB‐UVB in early‐stage MF both clinically and histopathologically. Materials and methods Twenty‐three patients (20 men, three women, aged 27–78 years) with clinically and histologically confirmed MF were enrolled. Patients received NB‐UVB therapy three times a week. Clinical and histological responses, cumulative doses, total number of treatments, side‐effects and duration of remission period were noted. Results Six patients had stage IA MF, 15 patients stage IB and two patients stage IIA. Eighteen patients had patch stage and five patients had plaque stage histopathologically. All of the patients in the patch group had a complete response (CR). In the plaque group, three patients (60%) had a CR and two (40%) had partial (PR) or no clinical response (NR). The clinical response between patch and plaque groups was statistically significant. Regarding the histopathological findings, 17 (94.4%) had complete clearing and only one (5.6%) patient had a partial improvement in the patch group. In the plaque group, one (20%) patient had complete clearing and four (80%) patients had partial or no improvement. The difference between the two groups was statistically significant. In the patch group, the mean cumulative dose was 90.15 J/cm² and the mean number of treatments was 35.33. In the plaque group, the mean cumulative dose was 90.67 J/cm² and the mean total number of treatments was 39.40. The differences were not statistically significant, either between the mean cumulative dose or the mean number of treatments. The mean duration of follow‐up was 10.87 months (range 1–25 months). Only one of the patients had a relapse. Conclusions NB‐UVB therapy for patients with early‐stage MF is an effective and safe treatment with the effect lasting for months. We suggest that clinical clearance correlates with histological improvement except for patients in the plaque stage.     

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.     

NB‐UVB (311–312 nm)‐induced lentigines in patients with mycosis fungoides: a new adverse effect of phototherapy

Background Lentigines are a common pigmentary disorder in adults and in patients treated by psoralen and ultraviolet A (PUVA) radiation. Their appearance following treatment with narrow‐band ultraviolet B (NB‐UVB) radiation has been reported in only two patients. Objective To describe the clinical and histological features of NB‐UVB‐induced lentigines their relation to dosimetry and the course of the eruption in patients with mycosis fungoides (MF). Methods The files of all patients with MF treated in our department in 2003–2010 were searched to identify those in whom lentigines appeared following monotherapy with NB‐UVB radiation. Results Of the 73 patients with early stage MF identified, 10 met the study criteria. Lentigines were detected in skin previously involved by MF in seven patients, and in both involved and uninvolved skin in three patients. They appeared during therapy in three patients, after a mean of 56 exposures (range 50–61), and several months (mean 7.8) following completion of treatment in seven patients, after a mean of 69 exposures (range 32–157). Histopathological study of lesions from five patients revealed basal hyperpigmentation relative to adjacent normal‐looking skin. Two lesions had a slight increased number of normal‐looking melanocytes on immunohistochemical staining with melanoma cocktail. One lesion had elongated rete ridges. The lesions persisted throughout follow‐up (mean 26.7 months) in 8 patients. Conclusions Patients with MF treated with NB‐UVB may acquire lentigines. As opposed to PUVA‐induced lentigines which are a known common side‐effect of long‐term treatment, NB‐UVB‐induced lentigines are uncommon but appear earlier, even after a few months of treatment.     

A modified dosage schedule for increased efficiency in PUVA treatment of psoriasis

Ten patients with chronic widespread plaque psoriasis, all of whom had previously completely cleared and suffered a subsequent widespread relapse after conventional PUVA therapy, were treated with a modified UVA dosage schedule, with psoralen formulation and dosage unchanged. Initial and incremental UVA doses were maximized to near-erythemogenic levels as determined by weekly testing for minimal phototoxic dose (MPD), treatment being given three times a week. A comparison of complete psoriasis clearing between the modified treatment and the last PUVA course showed a geometric mean reduction in treatment duration of 55% (P less than 0.001) for a similar number of treatments each week, and a cumulative UVA dose of 31% (P less than 0.05), representing a reduction in treatment duration from 9.1 to 4.1 weeks and cumulative UVA dose reduction of 100.8 to 69.9 J/cm2. Such an improvement in efficiency permits a marked increase in treated patient numbers for the same cost, and is more convenient. The reduction in the total cumulative UVA dose given as larger individual doses also seems likely to lead to a lower incidence of cutaneous long-term, especially carcinogenic, adverse effects.     

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.