Modelling bounded health scores with censored skew-normal distributions.

Health care interventions that use quality of life or health scores often provide data which are skewed and bounded. The scores are typically formed by adding up numerical responses to a number of questions. Different questions might have different weights, but the scores will be bounded, and are often scaled to the range 0-100. If improvement in health over time is measured, scores will tend to cluster near the 'healthy' or 'good' boundary as time progresses, leading to a skew distribution. Further, some patients will drop-out as time progresses, hence the scores reflect a selected population.We fit models based on the skew-normal distribution to data from a randomized controlled trial of treatments for sprained ankles, in which scores were recorded at baseline and at 1, 3 and 9 months after injury. We consider the extent to which skewness in the data can be explained by clustering at the boundary via a comparison between a censored normal and a censored skew-normal model.As this analysis is based on the complete data only, a formula for the bias of the treatment effects due to informative drop-out is given. This allows us to assess under what conditions the conclusions drawn from the complete data might be either reinforced or reversed, when the informative drop-out process is taken into account.

Antioxidant activity of topically applied lycopene.

BACKGROUND: Ultraviolet (UV) rays cause depletion of the antioxidant substances contained in the epidermis. This is the rationale for the use of topical antioxidant substances. METHODS: We studied the protective activity against UV radiation of a product based on lycopene and a product containing a mixture of vitamins E and C. Photostimulation was applied with a solar simulator and the cutaneous response was evaluated instrumentally. RESULTS: The lycopene-based product had a much greater protective ability than the product containing the mixture of vitamins. CONCLUSIONS: Lycopene has suitable characteristics to be used successfully in the prevention of cutaneous damage by free radicals. Its antioxidant ability is probably due to its high reductive power.

Extracorporeal photochemotherapy in the treatment of eosinophilic fasciitis.

BACKGROUND: Eosinophilic fasciitis (EF) is a rare connective tissue disorder characterized clinically by symmetrical swelling, induration and thickening of the skin and histologically by thickening of the fascia with chronic inflammatory infiltrate containing eosinophils. The disease is classified in the spectrum morphea/systemic sclerosis and treated with systemic steroids and other immunosuppressant drugs. OBJECTIVE: The purpose of this study was to use extracorporeal photochemotherapy (ECP) in patients with EF to evaluate the effectiveness of this therapy. SUBJECTS AND METHODS: Three patients affected by EF were treated with ECP because they failed to respond or with contraindications to immunosuppressant treatment. The patients underwent ECP with a UVAR XTS apparatus. Subjects were treated on two consecutive days at 2-week intervals for the first 3 months and thereafter every 4 weeks on the basis of clinical response. The patients were assessed before therapy and then monthly by means of a clinical score. Changes in affected areas were evaluated at predetermined points by computerized skin elastometry (Cutometer SEM 474). RESULT: After 1 year of therapy we found considerable improvement of clinical parameters in two cases. There was less striking improvement in the other case. These clinical results were confirmed by the elastometry measurements. All patients reported improved quality of life, which enabled a reduction in the dose of immunosuppressants. CONCLUSION: ECP emerged as a safe and effective therapy in association with low doses of immunosuppressants in our three patients. A randomized comparative multicentre study between ECP as single therapy and ECP plus immunosuppressants and conventional therapies is required to firmly establish photopheresis as a possible basic treatment to combine with conventional therapies for EF.

Inhibitory effects of Leopoldine spa water on inflammation caused by sodium lauryl sulphate.

BACKGROUND: Sulphur mineral waters may have anti-inflammatory effects on human skin. We evaluated the anti-inflammatory effects of Leopoldine spa water, a salso-sulphate water (Table 1), on human skin tested with sodium lauryl sulphate (SLS). PATIENTS AND METHODS: Ten healthy, Caucasian volunteers 28-53 years old were enrolled in this study. SLS was tested on the right arm, in two concentrations (0.5% and 1%) dissolved in both double-distilled nonpyrogenic water and Leopoldine spa water in four separate test tubes; 0.02 mL of each solution was applied via the testing apparatus (Vand der Bend chambers, four squares measuring 1 x 1 cm), which was fixed and remained in contact with the skin surface. The anti-inflammatory effect was measured via the variations of redness (chromometry, parameter a*), using a Minolta CR 200 chromometer. RESULTS: At base condition the values of a* of the areas that were tested ranged from 7.11 to 9.30 with a mean of 7.97. In regard to the reaction caused by SLS dissolved in double-distilled water, the values of a* ranged from 8.98 to 9.53, mean 9.24, for 0.5% SLS and from 12.81 to 14.33, mean 13.59, for 1% SLS. The a* values for the cutaneous reaction caused by SLS dissolved in Leopoldine spa water ranged from 7.22 to 9.60 (mean 8.20) for 0.5% SLS and from 10.8 to 12.36 (mean 11.68) for the 1% SLS. CONCLUSIONS: These data show the potential anti-inflammatory effects of Leopoldine mineral water on human skin affected by modest inflammatory reactions caused by the direct application of the chemical irritant SLS. Leopoldine spa water can, thus, be considered a natural therapeutic alternative for the treatment of inflammatory skin conditions.

A new device for objective assessment of skin type in Caucasians by violet light reflectance.

In the present study, we tested a new device called skin phototype diagnosis (SPD) built for the purpose of objectively determining skin phototype. We compared its performance with that of phototype determinations according to Fitzpatrick method and on tristimulus colorimetry (Minolta CR-200). Our population consisted of 100 subjects of Caucasian race (60 female, 40 male; mean age 33 years). Skin colour was measured with both devices (SPD and Minolta CR-200) on the medial surface of the arm (constitutional skin colour). Our study showed that the SPD gave a better representation of Fitzpatrick phototype, showing 89% concordance (evaluated by classification matrix) as against the 71% concordance of the L(*)a(*)b(*) and Yxy colorimetric systems. The present results are important because evaluation of phototype with the SPD device is easy, fast, objective and reliable. Moreover, this instrument has potential applications in cosmetology and in photodermatology.

Relationship between skin color and sun exposure history: a statistical classification approach.

In this study our aim was to determine the biophysical values of constitutive skin color in Caucasians and to define the correlation between skin color and phototype assessed according to the Fitzpatrick method. Constitutive skin color was measured on the buttock, with a Minolta CR-200 colorimeter, in a population-of 557 consecutive subjects belonging to phototype categories I, II, III and IV. The colorimeter expresses the results in five different color systems. We used the "Yxy" and L*a*b* systems, which are the most widespread in dermatology. Statistical analysis of the data showed that the "Yxy" system is even more discriminant than the L*a*b* system when the Fitzpatrick classification scheme is adopted as the reference and shows a poor ability to correctly classify the intermediate phototypes (II and III). On the contrary the "Yxy" system performs well in distinguishing phototypes I and IV. To establish whether this low discriminating capacity for phototypes II and III is related to a low discriminating capacity of the method suggested by Fitzpatrick or by our procedure, an objective technique (minimal erythemal dose) should be used to evaluate the percentage errors of classification of both the Fitzpatrick method and instrumental measurement of skin color. The results of such a study are extremely important because the evaluation of skin color is objective, simple and has potential applications in dermatology and cosmetology.