Photoadaptation to ultraviolet B TL01 in psoriatic patients.

BACKGROUND: In the biologic era, narrow-band ultraviolet B (NB-UVB) phototherapy still remains a valuable, effective, inexpensive, safe anti-psoriatic treatment. Patients can lose response to NB-UVB over time due to photoadaptation. This phenomenon is the tendency of the skin to respond to ultraviolet (UV) exposure by undergoing changes that may result in a decreased future response to an equivalent dose of radiation, thus leading to the need for an increased exposure during phototherapy course. AIM: To characterize and quantify the determinants of photoadaptation in NB-UVB treated psoriatic patients. METHODS: We enrolled 57 adult patients with moderate plaque psoriasis. Patients underwent 24 sessions of NB-UVB phototherapy delivered thrice a week. Dosing was started with 70% of the minimal erythema dose (MED) with percentage-based dose increments every two treatments. MED as well as change in the erythema and melanin index (MI) were measured at baseline and at the end of phototherapy course. Moreover, an adaptation factor (AF) was calculated for each patient. RESULTS: Adaptation factor was not influenced by both baseline MED and skin type. We found a weak correlation between higher cumulative dosages and the initial MED (Spearman's rho = 0.32, P = 0.0154) as well as with the mean initial MI (Spearman's rho = 0.25, P = 0.0624, statistically borderline). Clearance and mean number of treatments were correlated (Spearman's rho = 0.48, P < 0.001). CONCLUSION: Photoadaptation is a physiological skin response that negatively influences NB-UVB responsiveness and is not predictable by the baseline MED and skin type. Thus, starting with more aggressive protocols and increasing rapidly dosage progression to prevent AF may increase NB-UVB response.

'High dose' vs. 'medium dose' UVA1 phototherapy in italian patients with severe atopic dermatitis.

BACKGROUND: The current evidences attest UVA1 phototherapy as effective in the treatment of severe atopic dermatitis (AD). Furthermore, in this indication, 'medium dose' is as effective as 'high dose' regimen. To date, a randomized comparison study evaluating the effectiveness as well as safety of different UVA1 protocols in different skin types in the treatment of adult patients with severe AD is still lacking. OBJECTIVE: The aim of the present study was to compare the safety and the efficacy of medium and high dose UVA1 either in fair or in dark skin types. METHODS: Twenty-seven adult patients with severe AD were consecutively included in a randomized, controlled, open, two arms trial Severity of AD was determined by means of SCORAD index and clinical improvement was also monitored. A total of 13 out of 27 patients were treated with high dose (130 J/cm2 ) UVA1 protocol while 14 out of 27 patients received medium dose (60 J/cm2 ) UVA1 protocol. Phototherapy was performed five times weekly up to 3 weeks. Before and after UVA1 treatment each patient was evaluated for skin pigmentation through Melanin Index (MI) quantitative evaluation. RESULTS: Skin status improved in all patients resulting in a reduction of SCORAD index in all groups. Our results demonstrated that among patients with darker skin types and higher MI, high dose UVA1 was significantly more effective than medium dose (P < 0.0001) while within the groups with skin type II, no significant differences between high and medium dose protocols were observed. CONCLUSION: Our study, confirms previous observations that UVA1 phototherapy should be considered among the first approaches in the treatment of patients with severe generalized AD and also demonstrates that in darker skin types, high dose UVA1 phototherapy is more effective than medium dose in the treatment of adult patients with severe AD.

Tacalcitol and narrow-band phototherapy in patients with vitiligo.

BACKGROUND: Vitiligo is a skin disease characterized by loss of normal pigmentation in the skin. Several treatments exist but none is really effective. Recently, perturbations of calcium homeostasis in vitiliginous epidermis have been described. AIM: Based on these findings, the aim of this prospective, randomized, open-label study was to compare the effectiveness of narrow-band ultraviolet B (NB-UVB) phototherapy alone and the combination of NB-UVB and topical application of the vitamin D(3) analogue tacalcitol in the treatment of vitiligo. METHODS: In total, 32 subjects with generalized vitiligo and symmetrical lesions were enrolled in the study. Subjects were instructed to apply tacalcitol ointment daily to the lesion on the side randomly selected to receive combination therapy. All subjects received NB-UVB phototherapy on a twice-weekly schedule. RESULTS: Addition of topical tacalcitol to NB-UVB treatment improved the extent of repigmentation and increased the response rate in patients with vitiligo compared with NB-UVB treatment alone. CONCLUSION: Application of tacalcitol ointment in combination with twice-weekly NB-UVB phototherapy is an effective alternative treatment for patients with generalized vitiligo.

Monochromatic excimer light 308 nm in the treatment of vitiligo: a pilot study.

OBJECTIVE: To study the efficacy and safety of monochromatic excimer light (MEL) on 37 vitiligo patients referred to our clinic. METHODS: In a pilot study, 37 patients (17 males, 20 females) with acrofacial (n=21), focal (n=11), segmental (n=1), and generalized (n=4) vitiligo were treated twice weekly with MEL for a maximum period of 6 months. RESULTS: Thirty-five patients (95%) showed signs of repigmentation within the first eight treatments. The treatment resulted in good repigmentation in 16 patients, and excellent repigmentation in 18 patients. Adverse events were limited to transient erythema. In addition, some patients (n=3) not responding to prior narrow-band UVB (NB UVB) phototherapy showed good results with MEL in our series. CONCLUSIONS: Treatment with 308 nm MEL for vitiligo may be more effective in obtaining rapid repigmentation than phototherapy with NB UVB. The results in this study are similar to those recently reported with a 308 nm excimer laser, but 308 MEL could present some advantages: the possibility of treating larger areas compared to the 308 nm excimer laser, with shorter treatment times and better patient compliance. The overall good results and the early appearance of repigmentation contribute to reducing the cumulative exposure to UV radiation.

Prefrontal cortex lesions augment the location-related firing properties of area TE/perirhinal cortex neurons in a working memory task.

It has previously been proposed that prefrontal cortex may have some role in keeping temporal cortex-based representations "on-line" during a working memory task. To test this hypothesis, the effects of electrolytic prefrontal cortex lesions on the firing of area TE and perirhinal cortex (PRC) neurons were examined while rats performed a delayed non-match to position task in the T-maze. The behavioural performance of control (n = 4) and lesioned (n = 4) animals were similar during this task, and many neurons displayed a statistically significant location-related variation in firing rate during the sample (44/56 neurons) and test (39/56 neurons) phases. Units from prefrontal-lesioned animals (82%) were more likely to display a significant variation in firing across the maze compared to controls (50%; P < 0.01), and to have more discrete location-related properties (50% of neurons) compared to the control (5%) group (P < 0.0005). This finding suggests that prefrontal cortex normally modulates the transmission and/or processing of spatial information in area TE/PRC during a working memory task. Modulation could be mediated through direct connections between the structures or via prefrontal control of subcortical structures. This finding has implications for our understanding of prefrontal-temporal involvement in memory and cognitive disorders.

Analysis of the microtopography of the skin by silicone replicas after repeated exposure to actinic radiation at high altitudes.

We investigated the superficial microtopography of the normal skin of 11 volunteers (not exposed to sunlight during the last 4 months), before and after sun exposure for 5 days at high altitudes of 2900-4559 m. The experiments were carried out on Mount Rosa in Italy, and cutaneous replicas using silicone resin were taken every day after 7 h of sun exposure. Casts were taken from the forehead, glabella, dorsum nasi, radial side (protected with a cream SPF 9.72) and ulnar side of the back of the hands, the only areas not protected. A total of 422 replicas were metallized with gold-palladium and observed under Zeiss 940A scanning electron microscope. The images were elaborated and analysed on computer with appropriate software supplying geometrical features of cutaneous surface using parameters proposed by Takahashi (1994). A Student's test for paired series was used to analyse the differences before and after 1-5 days of exposure giving uniform and significant data compared with controls. Using cutaneous replicas we demonstrated that repeated exposure of skin to sunlight in a short time elicits temporary defence mechanisms with increased obstruction of cutaneous pores, deepening of primary cutaneous furrows and shallowing of part of the secondary furrows; the two latter alterations are the consequence of reactive oedema.