Vascularity and fractal dimension of the dermo-epidermal interface in guttate and plaque-type psoriasis.

BACKGROUND: Histological structures of the skin are often irregular in size and shape. Euclidean geometry and fractal analysis are complementary for assessing distinct aspects of their dimensions. OBJECTIVE: To determine and compare the variations in shape of the dermo-epidermal junction and the size of the superficial vessels in psoriatic lesions. METHOD: The relative microvasculature area and the fractal dimension D of the dermo-epidermal interface were measured inside and outside growth-stunted guttate lesions (n = 22) and expanding plaques (n = 37) in psoriasis of the trunk. RESULTS: The median D values of the dermo-epidermal interface were significantly larger (p < 0.01) in psoriatic plaques (D = 1.15) than in guttate lesions (D = 1.08), and these D values on lesional skin were significantly larger (p < 0.01) than in the uninvolved skin (D = 1.03). The microvasculature was significantly (p < 0.01) more developed in lesional (plaque: 13%, guttate: 8.20%) than in uninvolved skin (3.60 and 3.85%). No correlations were found between the relative microvasculature areas and the D values of the dermo-epidermal interface, both in the uninvolved and lesional skins of each psoriatic type. CONCLUSION: The absence of a relationship between modulations of the dermo-epidermal junction and vascular hyperplasia, both in expanding and stable psoriasis lesions, suggests that these events are regulated by different mechanisms and do not depend on each other.

Mosaic subclinical melanoderma: an Achilles heel for UV-related epidermal carcinogenesis?

Cutaneous cancers are not uncommon on the face of elderly patients. Melanin should protect, at least in part, against the ultraviolet (UV)-induced neoplastic damage. However, the density in melanin chromatophores is heterogeneous in the epidermis of Caucasian adults. The computerized UV light-enhanced visualization (ULEV) method is a sensitive tool to assess non-invasively this mosaic pattern of intra-epidermal melanin load. In this study, the combination of ULEV pattern analysis and image analysis were performed involving four groups of phototype III Caucasian subjects. The first group was composed of 55 patients aged from 65 to 75 years who suffered from several malignancies of facial skin. The second control group of 55 patients who never had developed skin cancers were matched with the first group for age, sex and phototype. The third group was composed of 80 patients aged from 49 to 59 years who had developed a single basal cell carcinoma. The fourth group comprised 80 age, sex and phototype-matched healthy control subjects. Irrespective of the groups of subjects, a correlation was found between the pattern grading and the objectively determined relative area of subclinical melanoderma. Patients with multiple skin cancers differed from the other groups by the fact that a significantly higher proportion of them exhibited an extensive type of subclinical melanoderma. This feature was also seen in a minority of patients with a single basal cell carcinoma. The extensive subclinical melanoderma pattern is interpreted as a clue for risk, but not as a cause of UV-induced skin carcinogenesis.

Revisiting the gender-linked melanoma burden.

BACKGROUND: Much is known about the worldwide rising incidence of skin cancers in the white populations. However, contradictory reports have been presented about a gender-linked risk for malignant melanoma (MM). OBJECTIVE: To review the recent epidemiological information about primary and metastatic MM in south-east Belgium. METHODS: Laboratory records of primary MM according to age and gender were compared per 3-year periods from 1988 to 2002. The numbers of MM per decade of patient age were corrected with regard to the number of citizens in the defined periods of age. This led to the calculation of the rate of estimated prevalence (REP). The same assessments were performed on 187 sentinel lymph node biopsies collected during the last 3-year period. RESULTS: A total of 1,051 primary MM in women and 594 primary MM in men were diagnosed over the 15-year period. The female-to-male ratio rose by 24% over time, with a mean value of 1.77. The most recent years showed a marked increase both in the numbers and REP of primary MM. This situation was present in both genders, although it was most prominent in women of the reproductive age. MM metastases were found in 38/187 sentinel lymph nodes with a female-to-male ratio of 2.17. The age distribution for all sentinel lymph node biopsies copied that of primary MM, but the vast majority of the nodal metastatic MM was found in patients older than 50 years. The ratio between MM metastases and primary MM reached 6.1% (12/198) in men and 6.9% (26/378) in women. CONCLUSION: A recent increase in primary MM incidence was observed in our laboratory. The most likely cause is ascribed to more sensitive MM detection using the combination of clinical dermoscopy and laboratory immunohistochemistry. During the past 15 years, women were more affected than men by both primary and metastatic MM. The gender difference in incidence of primary MM has progressively widened due to an increased incidence in young and middle-aged women. By contrast, nodal metastatic MM mostly affected postmenopausal women.

Updating trends in cutaneous cancers in south-east Belgium.

From data collected in a dermatopathology laboratory, the ratios between the numbers of specific cancers represent good markers for identifying any epidemiological shift in their prevalence and incidence among the reference population. The objective of the present study was to assess the ratios of the annual incidence of skin cancers in the Mosan region and Ardennes of Belgium over the past 6 years, and to compare the data with previous similar evaluations. A total of 7,640 skin cancers were collected and compared with regard to age and gender. Changes in time show that the trend of the increase in incidence of malignant melanoma (MM) is more impressive than that of squamous cell carcinoma (SCC) and basal cell carcinoma (BCC). The age distribution of BCC and SCC confirms the increasing risk with ageing. By contrast, there is a steady decrease over the past decade in the mean age for MM, teenagers and young adults now form an expanding proportion of MM patients. There is an ongoing trend in diagnosing an increased number of skin cancers in our laboratory. This trend is particularly obvious for MM affecting young adults.

Skin tensile properties revisited during ageing. Where now, where next?

Skin and its subcutaneous layer represent a complex composite of tissues, whose mechanical characteristics depend upon the mutual interdependence of their constituent parts. The molecular and microanatomical structures of skin allow it to meet normal mechanical demands. They also determine the orientation both of Langer's lines and of relaxed skin tension lines. Ageing, photodamage, hormones, drugs, cosmetic products and dermatological interventions may modify the skin's overall tensile properties. In turn, any variation in mechanical stresses and strains imposed upon the skin's connective tissue influences the metabolic activity and phenotypic expression of fibroblasts and dermal dendrocytes. The viscoelastic functions of ageing skin can be tested by altering the orientation and magnitude of imposed stresses and strains over time. Assessment can be made of various biomechanical properties of skin: tensile, torsional, acoustic shear wave, indentation, impact and elevation. Such objective biomechanical assessments may be applied to dermocosmetic interventions, so providing opportunity for progress in cosmetic dermatological science.

Nudging epidermal field cancerogenesis by imiquimod.

BACKGROUND: The coexistence of malignancies close to each other on the skin has been occasionally reported. The concept of field cancerogenesis applies to such cases. Given the purported mechanism of action of imiquimod, it should not be surprising that this treatment could inhibit epidermal field cancerogenesis. AIM: To assess the effect of imiquimod applied twice weekly on incipient bowenoid changes disclosed in the vicinity of basal cell carcinomas. MATERIALS AND METHOD: Biopsies were taken before treatment and after 4-6 weeks and 12 weeks of imiquimod treatment. RESULTS: Large atypical bowenoid keratinocytes and dyskeratotic cells were cleared in time while factor-XIIIa-positive dermal dendrocytes appeared boosted and admixed with a brisk lymphocytic infiltration. CONCLUSION: Epidermal field cancerogenesis appears to be controlled by imiquimod. Dermal dendrocytes might play a pivotal role in this regression phenomenon.

Histometric assessment of psoriatic plaques treated by vitamin D3 derivatives.

BACKGROUND: Psoriasis is an immunogenetic disorder. Factor XIIIa+ dermal dendrocytes (DD) are part of the pathobiological changes in the plaque type of the disease. OBJECTIVE: The present study aimed at comparing the effect of 3 vitamin D(3) derivatives on the epidermis, microvasculature and DD in psoriasis. METHOD: Twenty men suffering from chronic plaques of psoriasis on the trunk were enrolled in this study. They applied twice a day for 3 weeks calcipotriol, tacalcitol and calcitriol, each to one plaque. Another similar lesion received petrolatum as a placebo treatment. Skin biopsies were taken at entry and at completion of the 3-week treatment phase. Immunohistochemistry was performed using the lectin of Ulex europaeus and an antibody to factor XIIIa. Computerized image analysis served to measure the stratum Malpighii area, the microvasculature area and the DD numerical density in the papillary dermis. RESULTS: At entry in the study, the 4 test sites were indistinguishable with regard to the stratum Malpighii area, the papillary microvasculature area and the papillary DD density. The 3 histometric parameters appeared correlated with each other. At completion of the 3-week treatment phase, the 3 vitamin D derivatives had decreased the size of the stratum Malpighii. In addition, calcitriol had also reduced the DD density in the papillary dermis. No other significant changes were yielded. CONCLUSION: As assessed by histometry, the psoriatic epidermis responded to a short treatment using the 3 vitamin D derivatives. The better result compared to the control site was achieved by calcitriol. DD appeared to be most controlled by the same drug. The microvasculature did not appear to be decreased at the 3-week time point in treatment.

From skin microrelief to wrinkles. An area ripe for investigation.

Skin microrelief alters progressively with age. Wrinkles do not result from these changes but are superimposed upon them. Wrinkles result from structural changes in the epidermis, dermis and hypodermis. Four types of wrinkles can be recognized. Type 1 wrinkles are atrophic. Type 2 wrinkles are elastotic. Type 3 wrinkles are expressional. Type 4 wrinkles are gravitational. Each type of wrinkle is characterized by distinct microanatomical changes and each type of wrinkle develops in specific skin regions. Each is likely to respond differently to treatment. Skin microrelief and skin folds can be identified on histological examination. By contrast, only minimal dermal changes are found beneath permanent or reducible wrinkles compared with immediately adjacent skin. A series of objective and non-invasive methods is available to quantify the severity of wrinkling.

Split face study on the cutaneous tensile effect of 2-dimethylaminoethanol (deanol) gel.

BACKGROUND/AIMS: Beyond subjective assessments, the effect of skin tensors is difficult to assess. The present 2-phase randomized double-blind split face study was designed to compare the effect of a gel containing 3% 2-dimethylaminoethanol (deanol, DMAE) with the same formulation without DMAE. METHODS: In a first pilot study, sensorial assessments and measures of the skin distension under suction were performed in eight volunteers. In a second study conducted in 30 volunteers, shear wave propagation was measured. RESULTS: Large interindividual variations precluded any significant finding in the first study. The DMAE formulation showed, however, a significant effect characterized by increased shear wave velocity in the direction where the mechanical anisotropy of skin showed looseness. CONCLUSION: The DMAE formulation under investigation increased skin firmness.