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Psoriasis is a common chronic and disabling inflammatory disease that has an enormous physical, functional and psychosocial impact on patients' quality of life. To date several conventional therapies are available for the treatment of this condition (eg, cyclosporine, methotrexate, retinoids, and psoralen plus ultraviolet A) which, although providing clinical response, do not maintain long-lasting disease remission and at times show poor tolerability with potential toxicity thus limiting their use. A challenge in psoriasis management is to utilize precociously an adequate therapy and to achieve effective and safe maintenance of its clearance by improving both skin and joint manifestations as well as to prevent joint destruction and disability. Recent improvement in the knowledge of the pathogenesis of this disease was fundamental for the development of novel targeted treatment options that may be effective, safer and well tolerated on long-term administration periods, thus improving patient's quality of life. These novel agents, which are called "biologics", target specifically tumor necrosis factor-alpha (infliximab, etanercept and adalimumab) or T cells (alefacept and efalizumab).

A 74-year-old man presented with relapsing systemic anaplastic large cell lymphoma (ALCL) with cutaneous involvement who had a third recurrence of cutaneous lesions associated with inguinal lymphonodes enlargement. Due to severe worsening of general conditions, treatment with low dose bexarotene associated with interferon-aalphawas initiated. Four months later, skin nodules disappeared with reduction of lymphonodes size. Two months after stopping therapy, lymphonodal relapse of the lymphoma was seen; however, cutaneous lesions were still in complete remission. Association of low dose bexarotene with interferon-xalphaseems to represent a possible alternative therapy for relapsing systemic ALCL presenting as prevalent cutaneous involvement in patients with severe worsening of general conditions. In our case, this protocol was unable to maintain a longer disease free survival in comparison with the 2 previous polychemotherapy cycles. Further extended studies are required in order to define the possible rule of this combination therapy in relapsing systemic ALCL.

Several tools have been introduced in clinical trials to quantify the severity and the response to a given therapeutic regimen of both psoriasis and psoriatic arthritis. Each method present specific advantages and limitations. Here we will discuss some of the most popular clinical outcome measures of both psoriasis (Psoriasis Severity Index, Physician Global Assessment, National Psoriasis Fundation-Psoriasis Score, Dermatology Life Quality Index) and psoriatic arthritis (American College Rheumatology response criteria, Psoriatic Arthritis Response Criteria).

Background: Inflammation represents an early and key event in the development of both the cutaneous psoriasis and psoriatic arthritis. Compelling evidences indicate that the production of TNF-alpha plays a central role in psoriasis by sustaining the inflammatory process in the skin as well as in the joints. Among the multiple effects produced by TNF-alpha on keratinocytes, the induction of matrix metalloproteinase-9 (MMP-9), a collagenase implicated in joint inflammatory arthritis which acts as an angiogenesis promoting factor, might represent a key mechanism in the pathogenesis of the disease. Aims of the present study were to investigate a) the role of MMP-9 in the development of psoriasis by assessing the presence of MMP-9 in lesional skin and in sera of psoriatic patients; b) the association of MMP-9 with the activity of the disease; c) the relationship between MMP-9 and TNF-alpha production., Methods: Eleven psoriatic patients, clinically presenting joint symptoms associated to the cutaneous disease, were included in a therapeutic protocol based on the administration of anti-TNF-alpha monoclonal antibody (Infliximab). Sera and skin biopsies were collected before treatment and after 6 weeks of therapy. Tissues were kept in short term cultures and production soluble mediators such as TNF-alpha, MMP-9, MMP-2, VEGF and E-Selectin, which include angiogenic molecules associated to the development of plaque psoriasis, were measured in the culture supernatants by immunoenzymatic assays (ng/ml or pg/ml per mg of tissue). MMP-9 concentrations were also measured in the sera. The cutaneous activity of disease was evaluated by the Psoriasis Area and Severity Index (PASI)., Results: Clinical and laboratory assessment indicated that all but one patients had a significant improvement of the PASI score after three months of therapy. The clinical amelioration was associated to a significant decrease of MMP-9 (P = 0.017), TNF-alpha (P = 0.005) and E-selectin (P = 0.018) levels, spontaneously released by lesional biopsies before and after therapy. In addition, significant correlations were found between the PASI measurements and TNF-alpha (r2 = 0.33, P = 0.005), MMP-9 (r2 = 0.25, P = 0.017), E-selectin (r2 = 0.24, P = 0.018) production. MMP-9 levels were significantly correlated with those of TNF-alpha (r2 = 0.30, P = 0.008). A significant decrease of MMP-9 in the sera, associated to the clinical improvement was also found., Conclusion: Our findings show the existence of a direct relationship between MMP-9 and TNF-alpha production strongly suggesting that MMP-9 may play a key role in the skin inflammatory process in psoriasis.

Only a limited number of studies on cellulite have been published in the international literature and many of them reach somewhat antithetical conclusions. Consequently, it is not yet possible to reconcile the extreme differences of opinion which have lingered on for years concerning the nature of this disorder, as well as its origin and even the most basic aspects of its histopathological classification. It does not even have a recognized name: in fact, the term 'cellulitis' is used in scientific English to indicate a spreading gangrenous infection of the subcutaneous cellular tissue. The other terms used from time to time [panniculitis, lipodystrophy, edematofibrosclerotic panniculitis (EFP), liposclerosis, lipoedema, etc.] have quite different morphological and pathogenetic connotations in general. Over the last few decades, three major conflicting theories have emerged in relation to the ethiopathogenesis of cellulite. These indicate, respectively, the following causes: 1. Oedema caused by excessive hydrophilia of the intercellular matrix. 2. A homeostatic alteration on a regional microcirculatory level; this pathogenetic theory is summarized in a synthetic and self-explanatory denomination: EFP. 3. A peculiar anatomical conformation of the subcutaneous tissue of women, different from male morphology. These theories must all now be updated in the light of recent advances on the sophisticated and composite physiopathology of the adipose organ - which acts not only as a control device which regulates the systematic equilibrium of energy and modulates the food intake and the metabolism of other tissue substrate through a multiple glandular secretion of hormones and parahormones.

Background: Pyruvic acid is an alpha-keto acid that presents keratolytic, antimicrobial, and sebostatic properties as well as the ability to stimulate new collagen production and elastic fibers formation. Because of its low pKa and its small dimension, it penetrates rapidly and deeply through the skin, so far as to be considered a potent chemical peel agent. It has proven its efficacy for the treatment of many dermatological conditions such as acne, superficial scarring, photodamage, and pigmentary disorders. Pyruvic acid application usually induces intense burning, and the postpeeling period is characterized by erythema, desquamation, and, sometimes, crusting., Objective: The aim of the study is to assess the efficacy and tolerability of 50% pyruvic acid in a new non-erythematogenic formulation (pyruvic acid 50%, dimethyl isosorbide, propylene glycol, ethyl alcohol, dimethyl sulfone, ethyl lactate, water) for the treatment of photodamage, superficial scarring, and melasma., Materials and Methods: Twenty subjects affected by photodamage, superficial scarring, and melasma, but otherwise healthy, entered the study. Four peeling sessions were performed once every 2 weeks. The patients were evaluated clinically and by means of several noninvasive methods in order to monitor the following parameters: hydration, color (erythema and pigmentation), elasticity, skin smoothness, skin roughness, scaliness, and wrinkles., Results: The patients did not report any discomfort either during the peeling session or during the postpeeling period, without any impact on their social life. We did not observe any case of persistent erythema as well as any case of postinflammatory hyperpigmentation. Instrumental evaluations showed a significant reduction in the degree of pigmentation in patients with melasma, a significant increase in skin elasticity, and an improvement of the degree of wrinkling in all the patients., Conclusion: This innovative formulation of 50% pyruvic acid peel has been shown to be safe and effective to treat photodamage, melasma, and superficial scarring, allowing the patients to carry out regularly their working life as well as their social life. Furthermore, the results have been evaluated by means of noninvasive devices, which have permitted one to quantify the improvements.

Topically applied cosmetic products can be helpful in improving skin hydration. The study shows how oral supplementation could be helpful in improving and preventing the skin dehydration. A total of 32 healthy female volunteers entered the study. Of which, 16 were treated with a food supplement based on vegetable ceramides, amino acids, fish cartilage, antioxidants and essential fatty acids for 40 days and 16 with placebo. The results of the clinical and instrumental evaluations carried out in this study, have highlighted how the active treatment is effective in improving skin hydration and in reducing the cutaneous smoothness and roughness and the depth of furrows, in comparison to the placebo. In fact, concerning several important parameters, as stratum corneum hydration and skin roughness, the improvement measured exceeded 25%. We therefore suggest that a combination of treatments (oral and topical) can be more effective in improving skin hydration.

Sensitive skin is a condition of subjective cutaneous hyperreactivity to environmental factors. Subjects experiencing this condition report exaggerated reactions when their skin is in contact with cosmetics, soaps and sunscreens, and they often report worsening after exposure to dry and cold climate. Although no sign of irritation is commonly detected, itching, burning, stinging and a tight sensation are constantly present. Generally substances that are not commonly considered irritants are involved in this abnormal response. They include many ingredients of cosmetics such as: dimethyl sulfoxide, benzoyl peroxide preparations, salicylic acid, propylene glycol, amyldimethylaminobenzoic acid and 2-ethoxyethyl methoxycinnamate. Sensitive skin and subjective irritation are widespread but still far from being completely defined and understood. The aim of this paper is to summarize the relevant literature in order to elucidate the underlying mechanisms of sensitive skin and the best testing methodologies for investigation of sensitive skin.

Racial variability in skin function is an area in which data often conflict. Understanding and quantifying racial differences in skin function are important for skin care and the prevention and treatment of skin diseases. A key feature that characterizes race is skin color: Is deeply pigmented skin different from fair skin in terms of responses to chemical and environmental insults? Is skin care the same? Are there different risks among racial groups of developing a skin disease after exposure to the same insults? The interpretation of pathophysiologic phenomena should consider not only anatomic and functional characteristics of ethnic groups but also socioeconomic, hygienic, and nutritional factors. This article reviews and discusses recent findings.

Background: Eyelids can be affected by various types of dermatitis that are often difficult to diagnose., Objective: The aim of the study was to establish some guidelines for a correct diagnosis., Methods: A total of 447 patients treated at 12 research units for eczema or other inflammatory dermatitis located on the eyelids were invited to complete a questionnaire. When necessary, patch tests with haptens of the standard series from Gruppo Italiano di Ricerca sulle Dermatiti da Contatto e Ambientali della Società Italiana di Dermatologia e Venereologia (SIDEV-GIRDCA) were performed., Results: Of the subjects studied, 50.2 % were diagnosed with allergic contact dermatitis (ACD); 20.9% were affected by irritant contact dermatitis (ICD), 13.5% by atopic dermatitis, 6.3% by seborrheic dermatitis, 6.5% by aspecific xerotic dermatitis, and 2.3% by psoriasis. Approximately 91% of all subjects reported an absence of familial atopy. A significant statistical association between diagnosis type and a personal history of atopy was evident (p <.000001, chi-square test). The results of gradual logistic regression models showed four-eyelid involvement as the main risk factor for ACD (odds ratio [OR] = 3.0; 95% CI, 1.1-8.1); with ICD, the main risk factor was the onset of symptoms at between 2 and 6 months (OR = 2.1; 95% CI, 1.1-4.0), whereas for atopic dermatitis, the main risk factors were the onset of symptoms later than 6 months and a personal history of atopy (OR = 4.9 and 3.6, respectively)., Conclusion: Results suggest that many characteristics of the patients examined can be used for the differential diagnosis of palpebral eczematous dermatitis.

The blood supply to the skin is provided by a network of arterioles, capillaries and venules organized into a superficial and a deep plexus. The assessment of skin microcirculation is of valuable interest in cosmetology in the quantification of the sun protection factor, skin irritation and efficacy of antiredness treatments. Skin microcirculation can be measured by means of different techniques, based mainly on the quantification of optical and thermal properties of the skin which are modified by the amount of blood perfusion. Relevant and reproducible data can be obtained only through the understanding of the biophysical background of the technique(s) utilized. Standardization of measuring conditions and procedures is particularly required for blood flow assessment. In this paper, the advantages and disadvantages of the main techniques in use are discussed, and optimization of measurements for laser Doppler techniques is described., (Copyright 2002 S. Karger AG, Basel)

Disturbances of skin barrier function occur in several skin diseases, e.g., atopic dermatitis (AD), irritant/allergic contact dermatitis (ICD, ACD). Skin barrier damage triggers the production of cytokines that stimulate lipogenesis which may also cause inflammatory processes. The aim of this study was to evaluate the efficacy of a topical skin lipid mixture in the treatment of ICD, ACD and AD. 580 consecutive patients suffering from ICD, ACD or AD were treated with a skin lipid mixture containing ceramide-3 and patented nanoparticles. Patients received the lipid mixture alone or in combination with topical corticosteroids until clearance or for 8 weeks. Both treatment groups statistically improved all parameters considered at week 4 and 8 as compared to baseline. Between the 2 treatment groups, there was a statistically significant difference in favour of combined therapy for (ICD, ACD, AD, respectively): erythema, pruritus and overall disease severity; erythema and pruritus; erythema, pruritus, fissuring and overall disease severity. No statistically significant difference was found for (ICD, ACD, AD, respectively): dryness, scaling and fissuring; scaling, fissuring and overall disease severity; dryness and scaling. Between the 2 ACD treatment groups, there was a statistically significant difference in favour of the skin lipid mixture for dryness. In conclusion, the study shows that balanced lipid mixtures are effective in improving barrier properties and the clinical condition of the skin in contact dermatitis.

This study analyses the ability of four non-invasive techniques (laser Doppler velocimetry, evaporimetry, chromametry and corneometry) to discriminate between irritant and non-irritant products, when compared to appropriate controls, and to detect subliminal changes in barrier function and erythema. These changes, which remain undetectable in the traditional visual and palpable clinical assessment, can be used as early reactions that are followed by the development of overt skin irritation. Laser Doppler velocimetry and evaporimetry were good discriminators between irritant and non-irritant substances, whereas corneometry and chromametry did not clearly distinguish between them. Laser Doppler velocimetry and evaporimetry detected early stages in the development of an irritant reaction before it became visible, but chromametry was not able to detect an early irritant response. It was concluded that non-invasive measurements could improve the quality and relevance of data obtained from human irritation testing, since the data they provide are objective, quantitative and sometimes subclinical, which also allows the concentration of a positive control to be reduced, resulting in the induction of less skin damage in human volunteers and reducing the ethical concerns related to the deliberate induction of an irritant response in a 'healthy' volunteer.

We tested an OTC formulation versus placebo in a double-blind trial to evaluate its ability to improve elasticity and firmness of the skin. The clinical non-invasive evaluation in 20 volunteers shows: 1. No adverse reactions such as itching or irritation 2. Efficacy and cosmetic acceptibility of the test cream 3. An increase in electrical capacitance (moisture content) even though without statistical significance. This result is not surprising because the patients had healthy skin and were relatively young (aged 20-25) 4. A very significant improvement in the biomechanical properties (extensibility and firmness) of the skin. This increase was statistically significant (P < 0.02) The main components of the cream (boswellic acids, Sylibin and Centella asiatica extracts) were formulated as complexes with lyso-phospholipids and soya bean non-saponifiable lipids.

Purpose of the Study: We aimed to evaluate whether prolonged occlusion can induce stratum corneum barrier damage, alterations in stratum corneum hydration or water-holding capacity (WHC) lasting longer than the occlusion time., Materials and Methods: 12 subjects were occluded on the forearm for 24, 48, 72 and 96 h. Two hours after occlusion removal, transepidermal water loss (TEWL) and skin hydration were measured and a sorption-desorption test performed., Results: TEWL showed an increase reaching a plateau on day 2. Hydration and WHC did not show significant changes. Hygroscopicity showed the highest level on day 1, decreasing during the following days. A highly significant correlation between capacitance values and the WHC could be detected (p < 0.0001, r = 0.8206). No correlation could be detected between hygroscopicity and TEWL., Conclusions: Prolonged occlusion induces barrier damage without skin dryness. Occlusion also induces an increased hygroscopicity. A correlation between these two findings could not be proven.

This study assessed pH gradient changes in relation to stratum corneum (SC) depth and possible differences between white caucasian and black African-American skin. Ten white and eight black people entered the study. SC was progressively removed by cellophane tape stripping on the volar forearm and weighed with a microbalance. Transepidermal water loss (TEWL) and SC pH were measured every three tape strippings. Significantly increased TEWL and decreased pH values were found with increasing SC depth in both races. Significantly increased TEWL in black people was found after three and six tape strippings (P < 0.05 and 0.03, respectively); pH was significantly decreased in black people after three tape strippings (P < 0.005). No differences were found between the races after nine, 12 and 15 strippings, i.e. in the deeper SC layers. The data confirm that pH in the superficial SC layers decreases with SC depth; only total SC removal results in increased pH values. In the superficial layers, there are significant differences in both water evaporation and skin pH, possibly explaining the contradictory literature.

Alpha hydroxyacids (AHAs) are used to enhance stratum corneum desquamation and improve skin appearance. The purpose of this study was to evaluate whether some AHAs improve skin barrier function and prevent skin irritation. Eleven healthy subjects (aged 28 +/- 6 years, mean +/- SD) entered the study. Six test sites of 8 x 5 cm (four different AHAs, vehicle only (VE) and untreated control (UNT) were selected and randomly rotated on the volar arm and forearm. The four different AHAs at 8% concentration in base cream were glycolic acid (GA), lactic acid, tartaric acid (TA) and gluconolactone (GLU). The products were applied twice a day for 4 weeks (2 mg/cm2). At week 4, a 5% sodium lauryl sulphate (SLS) challenge patch test was performed under occlusion for 6 h (HillTop chamber, 18 mm wide) on each site. Barrier function and skin irritation were evaluated by means of evaporimetry (Servomed EP-1) and chromametry (a* value, Minolta CR200) weekly, and at 0, 24 and 48 h after SLS patch removal. No significant differences in transepidermal water loss (TEWL) and erythema were observed between the four AHAs at week 4. After SLS challenge, GLU- and TA-treated sites resulted in significantly lower TEWL compared with VE, UNT (P < 0.01) and GA (P < 0.05) both at 24 and 48 h. Similarly, a* values were significantly reduced after irritation in GLU- and TA-treated sites. This study shows that AHAs can modulate stratum corneum barrier function and prevent skin irritation; the effect is not equal for all AHAs, being more marked for the molecules characterized by antioxidant properties.

Background/aims: The improvement of stratum corneum hydration is one of the most important claims in the cosmetic industry., Methods: Objective assessment of moisturization can be done with devices based on electrical methods provided these instruments are used in an appropriate manner., Results: This paper deals with the biophysical basis behind these techniques and describes the most important variables, pitfalls and drawbacks related to measurements and current instrumentation. Individual-related and environment-related variables are also analyzed as well as study designs for predictive or use tests., Conclusions: Practical suggestions for standardization of measurements are given.

An increase of sebum excretion rate (SER) is frequently observed in patients suffering from Parkinson's disease (PD). Some authors attribute it to the hyperactivity of the parasympathetic system, while others consider the possible action of androgens or of MSH-hormone. The aim of our study was to verify and quantify SER in 70 parkinsonian patients and compare it with SER in 60 normal subjects. We found higher values of SER in male subjects, both in normal and in parkinsonian patients. The highest rate of excretion was observed in parkinsonian males, in agreement with the possible main role of androgens or testosterone in sebum excretion, while the phenomenon did not appear to be related to abnormalities of the autonomic nervous system. The association of PD and sex hormones might therefore be crucial for the developing of seborrhea.

Background/aims: Areas of the skin with similar anatomical structure may have different functional behaviour. In vivo barrier function and stratum corneum water-holding capacity during the menstrual cycle on two sites of the volar forearm (upper and lower) and on the anterior aspect of the thigh were evaluated using the plastic occlusion stress test (POST)., Methods: 13 healthy women (age 31 ± 4) with regular menses entered the study. POST was performed by applying a plastic chamber (1.8 cm diameter) on the skin for 24 h. After removal the skin surface water loss (SSWL) was measured using an evaporimeter (EP1-Servomed, Sweden) every 5 min for 30 min. Measurements were taken on the 10th and 25th day of the menstrual cycle. Statistical analysis was performed using one-factor Anova for repeated measures. Free and bound water compartments of evaporation were also analysed., Results: Higher hydration and SSWL were detectable on the 25th day of the cycle. However, no significant influence of menstrual cycle was found. Significant differences between the upper and lower volar foream were detected (P < 0.001)., Conclusion: The differences observed were mainly related to the evaporation of bound water, confirming a different barrier function at the sites investigated; therefore, it must be taken into account that adjacent skin sites with equal structure may have different functional behaviour.

Surfactant-induced irritant reactions may be elicited by several endogenous and exogenous factors. Among these, surfactant concentration, and duration and frequency of exposure play important rôles. The study focuses on the influence of water temperature in determining damage of the skin barrier. 10 subjects of both sexes entered the study. 4 areas (4 x 4 cm2) were randomly selected on the volar forearm and were treated with a daily open application of 5% sodium lauryl sulphate for 4 days. The solutions were at 3 temperatures: 4 degrees, 20 degrees and 40 degrees C. One site served as untreated control. On the 5th day, skin irritation was evaluated using transepidermal water loss (TEWL) measurements, erythema (a* value), skin reflectance (L* value), hydration (capacitance) and desquamation (stripping). The results show a significant effect of the solution's temperature in determining skin irritation (P < 0.001). Skin damage was higher in sites treated with warmer temperatures and a highly significant correlation (P < 0.001) between irritation and temperature was found. In conclusion, the study shows that water temperature during washing has an important effect on the onset of irritant contact dermatitis.

Irritant contact dermatitis (ICD) is a multifactorial disease, the onset and modulation of which depend on both endogenous and exogenous factors. Among the former, age, race, site, sex and history of dermatitis may all be important. Such variables can now readily be quantified by objective noninvasive techniques, such as measurement of transepidermal water loss (TEWL). Moreover, effects of irritants on the epidermis are related to the particular chemical properties of each molecule, contributing further to clinical heterogeneity. Release of cytokines and mediators may be initiated by a number of cells, including living keratinocytes and those of the stratum corneum, thus modulating inflammation and repair. Furthermore, differences in mechanisms of inflammation between acute and chronic ICD may exist, the former being characterized predominantly by inflammation, the latter by hyperproliferation and transient hyperkeratosis. These findings may explain the complexity and difficulty of investigating ICD. Better understanding and quantification of these mechanisms may lead to identification of high-risk individuals and more effective prevention and treatment.

The cumulative and comparative effects of chronological and actinic changes to the skin were studied in an elderly population. Two adjacent sites with different degrees of exposure to the sun were examined to distinguish the contribution of each factor, by means of noninvasive measurements. The following parameters were measured on the skin of the low neck (an exposed site), as well as on the adjacent clothes-protected skin of 30 elderly women: electrical conductance, color, microrelief, biomechanical properties and the thickness of both the full skin and the subepidermal nonechogenic band (SENEB), using ultrasound measurements. Persistent exposure to the sun accentuated most of the age-induced modifications. The following changes were significantly more marked in exposed skin: SENEB thickening, full-skin thinning, loss of extensibility and elasticity, and color heterogeneity. The cumulative effects of sun exposure and chronological aging lead to atrophy in elderly people. These results suggest that, if there is an autoprotective skin reaction, such as thickening in young adults, it is eliminated in old people.

Topical treatment of psoriasis with calcipotriol has been proven effective. The efficacy of calcipotriol has been compared to that of topical corticoids in a number of studies using subjective visual scoring systems such as the PASI index. The purpose of this study was to compare, with objective data, the efficacy of calcipotriol and clobetasol propionate 0.05% in the treatment of plaque type psoriasis. Transepidermal water loss (TEWL) and laser Doppler velocimetry (LDV) were used to monitor restoration of water barrier and normalization of blood flow, respectively, in psoriatic plaques of the limbs of 24 male patients during 3 weeks of treatment. Data were compared to subjective evaluation using the PASI index of the same areas. Significant differences were recorded during treatment in both groups. The results correlated well with the PASI score. Clobetasol was faster in restoring barrier function than calcipotriol. However, no significant differences were detected between the two groups. The use of vitamin analogues may be effective in the topical treatment of psoriasis by normalizing skin biophysical parameters and minimizing the risks of side-effects induced by potent topical corticoids.

Psoriatic patients may offer a useful model for PUVA-induced skin wrinkling. This study deals with the changes induced by PUVA therapy on the cutaneous microrelief of psoriatic patients assessed by surface replicas. A non-exposed body area (buttocks) was considered. The microrelief was evaluated by means of replicas analysed by an automatic image analyser. Three groups of patients were considered: 1) 10 psoriatic patients who had been undergoing PUVA treatment for the first time and who had received a total PUVA dose of 200 +/- 20 J/cm2; 2) 16 psoriatic patients in long-term PUVA treatment (> 1000 J/cm2); 3) 13 psoriatic controls whose buttocks had never been affected by psoriasis nor exposed to sunlight or PUVA. The results showed that the number and the entity of the cutaneous crests and furrows had been increased by PUVA therapy. In particular the skin pattern analysis showed significant statistical differences between the second and the third group, while no changes were evident between the first and third group (ANOVA and Tukey test for multiple comparisons). In conclusion, our findings indicate that long-term PUVA therapy causes marked changes in the cutaneous microrelief, that this phenomenon can be measured non-invasively and that the changes observed are dependent on the PUVA-dose energies received.

Transcutaneous gas measurements offer a useful tool for non-invasive monitoring of skin function, but are affected by several variables that restrict their use in clinical and investigative dermatology. Skin thickness, stratum corneum and barrier function damage, blood vessel reactivity, arterial-gas concentration, skin and environmental temperature are important factors influencing transcutaneous gas flux. Improvement of techniques and standardization of methods with guidelines for operators should improve this interesting research approach.

Prick test reactions are evaluated and quantified, comparing visual assessment with two non-invasive techniques: remittance spectroscopy and pulsed ultrasound for erythema and skin thickness measurements. Different information is provided by the two methods. Remittance spectroscopy discriminates well between negative and positive reactions (+ or ++), while failing to differentiate stronger reactions, where edema is a prominent feature. The latter reactions are better evaluated by skin thickness measurements, which, on the contrary, are less sensitive in revealing small skin thickness increases in weak reactions.

Occlusion of the skin is used in clinical dermatology to promote wound healing and to increase the transcutaneous penetration of topically applied drugs. These effects are related to the degree of occlusion exerted and depend on the physicochemical nature of the dressing. We have evaluated the effects of four different materials on the skin barrier and the stratum corneum water holding capacity (WHC) using the Plastic Occlusion Stress Test (POST). The following materials were compared: hydrocolloid dressing, polyurethane film, polyethylene film, and a plastic chamber. These devices were applied on the volar forearm for 24 hours in 10 healthy volunteers (mean age 32 +/- 4 years). Upon their removal, the stratum corneum WHC, measured as skin surface water loss (SSWL), was recorded continuously for 25 minutes using an Evaporimeter. SSWL decay curves showed significant differences between the occlusive materials (analysis of variance, p less than 0.01). Higher SSWL values were recorded in sites occluded with the plastic chamber, whereas the polyurethane film resulted in poor occlusive capacity. Hydrocolloid dressing and polyethylene gave similar responses with higher WHC values compared to polyurethane (p less than 0.05). The relevance of these findings to clinical dermatology in terms of wound healing and drug absorption is discussed.

Proclivity to develop irritant reactions and transcutaneous penetration of nicotinates has been investigated in 20 subjects of both sexes, divided into reactors and nonreactors on the basis of the responses to irritant stimuli. 1% sodium lauryl sulphate (patch application for 24 h) and 5% lactic acid in aqueous solutions were used to detect chemical and sensory (subjective) irritation. The vasodilatation induced was measured using a chromameter for 1 h after topical application of the chemical. The area-under-the-curve response and the peak response was used to assess the in vivo penetration of methyl nicotinate (10 mM in aqueous solution). Significant differences were found between reactors and non-reactors. Non-reactors showed a significantly decreased area-under-the-curve response and peak response to methyl nicotinate compared to reactors. Nicotinate-induced vasodilatation has been used as a model to study transcutaneous penetration of chemicals; the correlation between increased penetration of nicotinates and skin hyperreactivity to irritant substances may suggest an increased transcutaneous penetration of water-soluble chemicals in individuals with sensitive skin.

Sensitive skin is a complex problem with genetic, individual, environmental, occupational, and ethnic implications. Further work is needed to rank irritants and irritant reactions to classify sensitive skin on the basis of standard models. The development of topical products designed for sensitive and ethnic skin may be advisable to optimize drug activity with minimal side effects. The availability of transdermal systems for drug delivery highlights the problem. Occlusive transdermal patch systems for delivery of clonidine show sensitization rates of 34% in white women, 18% in white men, 14% in black women, and 8% in black men. Besides ethnic differences in transcutaneous penetration, individual and ethnic skin sensitivity may play an important role in determining both patient compliance and therapeutic efficacy of drugs and cosmetics; furthermore, a drug formulation considering skin physiology may prevent unwanted local and general adverse effects.

Transepidermal water loss (TEWL) and water content of the stratum corneum, when measured simultaneously, provide important information regarding skin function. On the basis of the model presented, it is possible to differentiate dry senile skin from dry pathological skin (such as psoriasis, atopic dermatitis, irritant reaction), clinically involved or uninvolved. Pathological dry skin, because of the impaired barrier function is associated with increased TEWL and low corneum water content. Senile skin, on the other hand, shows both, decreased TEWL and stratum corneum water content. It is suggested that with this model it may be possible to differentiate uninvolved pathologic from healthy skin.

Hydration and the water-retention capacity of stratum corneum have been investigated in uninvolved psoriatic and atopic skin and compared with that of healthy controls. Thirty-three subjects of either sex and matched for age entered the study. The subjects were free from all signs of skin disease and skin dryness. Hydration was evaluated by means of transepidermal water loss and skin capacitance measurements. Water-retention capacity was investigated using the plastic occlusion stress test. Atopic skin differed significantly from uninvolved psoriatic and control skin which had a reduced water content and an increased transepidermal water loss. Furthermore, the skin surface water loss profile representing the stratum corneum water-retention capacity was significantly lower in normal atopic skin. The data suggest that clinically normal skin may be functionally abnormal, resulting in a defective barrier that could lead to higher risk of irritant or contact dermatitis.

This study evaluated the vasodilation induced in young whites and blacks by topical application of two nicotinates, methylnicotinate (MN) and hexylnicotinate (HN) at the same concentration and in the same vehicle. To assess the influence of skin surface lipids and water content of the stratum corneum on the penetration of the substances, the drugs were applied on the back, on untreated skin and pre-occluded and pre-delipidized sites. Skin blood flow was monitored with laser Doppler velocimetry. The initial response recorded at 15 min (IR), the peak response (PR) and the area under the curve (AUC) were used to characterize the pharmacodynamic response. Statistically significant racial differences in the penetration of nicotinates were detected for the area under the response curve in the untreated and occluded sites, for the initial response and peak response in the pre-occluded site. Occlusion increased (even though not significantly) penetration, except for blacks in the methylnicotinate experiment. Delipidization elicited significantly lower responses for the IR and PR in the MN study, rendering the penetration similar in the two groups. No major differences were recorded between the two nicotinates. The effect of delipidization was most noticeable in blacks in the MN study. We suggest that there are racial (blacks vs. whites) differences in percutaneous penetration of nicotinates, with decreased levels in black skin recorded in all sites investigated.

Black skin is characterized by structural and functional differences such as increased stratum corneum cohesion, melanin content, and stratum corneum layers. These differences seem to make black skin difficult for irritants and light to penetrate, thus explaining the common opinion that skin in blacks is harder and develops contact dermatitis less frequently. The paucity of interpretable epidemiologic data and of clinical and experimental studies does not permit confirmation of this hypothesis, and the few data available are controversial. This article describes the main physiologic differences between black and white barrier function and reviews the literature on irritation, sensitization, and transcutaneous penetration. We found that the data are still too incomplete to generalize on the resistance, or lack thereof, of black skin (versus white skin) to chemical irritation, sensitization, and penetration.

The hydrating power of a topically applied mixture of glycosaminoglycans has been evaluated by means of an electrical impedance method. The electrical parameters investigated, namely angle alpha and R infinity, are related to the permeability and the hydration of deeper tissues. The study revealed lowering of alpha levels after the application of the product, thus signifying an accumulation of electrical charges in the epidermis consistent with the penetration of glycosaminoglycans. After 15 days of treatment, significant reduction of R infinity levels was recorded. The relationship between R infinity levels, dermal water content and glycosaminoglycans is discussed.

The plausibility of the concept of "sensitive skin" evokes discussion and often amusement, because of the variance of the number of opinions compared with the amount of data, at least until recently. This report presents recent biologically oriented data that suggest that sensitive skin is a reality and is assessable with the use of contemporary methods.

We have studied the electrical behaviour of the skin on 20 volunteers, before and after cleaning with solid detergent. The aim was to study one of the possible variables of the measurements. The results have shown that the cleaning has globally reduced the electrical skin parameters of the forehead, without influencing other parts examined (dorsal and palmar surfaces of the hand). The result has been attributed to the elimination of the hydrolipidic film of the surface and in particular that of the sebum of the forehead. The data give an idea as to how to obtain more homogeneous final results, as well as studying the sebum production function.

The influence of female sex hormones on mechanical properties of the skin has been assessed in an in vivo extensometric study. Twenty young (20 +/- 4 years) and 12 middle-aged healthy women (42 +/- 3 years) entered the study. Measurements were carried out on the volar surface of the left forearm on the 10th and 25th day of the menstrual cycle. A significantly decreased skin extensibility time in the pre-menstrual phase was found (25th day) when compared with the 10th day in the young group, while the older one did not reveal significant changes. The data are compatible with an increased water content of the skin noticeable in the pre-menstrual phase and more relevant in young women. In studies on mechanical properties of the skin, changes relative to sex hormones and menstrual cycle need to be taken into account.

Three to four months' PUVA treatment is a widely-adopted procedure to induce psoriasis remission and for the purpose of this study is called "medium-term". The 32 psoriatic patients considered revealed a statistically significant baseline decrease in OKT3+ (p less than 0.001), OKT4+ (p less than 0.001) and OKT8+ (p less than 0.001) as compared with 40 healthy controls, while OKT4/OKT8 was normal. Variance analysis within the psoriatic group failed to reveal further significant variation in the immunological parameters during the 3 months under study. Nevertheless, there was a marked trend towards a reduction in OKT4+ cells and OKT4/OKT8 as compared with baseline values after 3 months. These results suggest that "medium-term" PUVA therapy does not statistically restore the pre-existing baseline changes in T-lymphocyte subsets of the psoriatic patients. The non-statistically significant effects as regards OKT4+ may be due to the small number of patients who reached 3 months' treatment (9 patients) but could be regarded as the first step towards the significant changes described here in long-term PUVA-treated psoriatic patients.