Photoexposed Skin Research Articles

The effect of aging on mast cell density in human skin: a comparative analysis of photoexposed and photoprotected regions.

Mast cells are mononuclear cells originating from bone marrow. They produce various biologically active substances, which allow them to actively participate in immune and inflammatory processes associated with intrinsic and extrinsic skin aging. This research focused on distribution and density of mast cells in healthy skin in different stages of skin aging. This project included samples of photoexposed and photoprotected skin, obtained from 90 cadavers aged 0-82 years. The samples were classified into five age groups: newborns, young age, middle age, senior age and the oldest age. In order to visualize the mast cells, we have employed several histochemical staining protocols. The number of mast cells of the photoexposed skin significantly correlated to the individual's age. The number of mast cells of the photoprotected skin was in general statistically significantly lower in younger compared to older groups; however, the correlation of the mast cell density in photoprotected skin and the age did not reach statistical significance. In middle age, senior age and the oldest age groups, a significantly higher number of mast cells was recorded in the skin of the photoexposed compared to photoprotected region. The increase in mast cell density correlated with age only in photoexposed skin. Age-related higher accumulation of dermal mast cells in photoexposed skin can be an important factor in the photoaging process, as well as the contributing factor in the occurrence of skin cancer.

Pigmented nonmelanoma skin cancers of the genital area: adiagnostic and therapeutic challenge - monocentric experience and review of the literature.

Nonmelanoma skin cancers (NMSC), comprising basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), are typically encountered on photo-exposed skin. Nevertheless, several cases of NMSC have been described in covered areas such as the genital region; furthermore, some of these lesions may express a variable degree of pigmentation. Due to the existence of mucosal melanoma, an accurate diagnosis is paramount. In this narrative review, we focused our attention on management and - in particular- diagnosis of pigmented NMSC (pNMSC) located in the genital region, emphasizing the features assessed by dermoscopy and reflectance confocal microscopy. As an implementation, we included data on pNMSC from the Dermatology Unit of the University of Campania Vanvitelli. BCC in the genital region represents only 1% of all BCC cases. It has been supposed that the mutation of patched 1 may lead to the development of BCC even without concomitant UV exposure. Pigmented variants on genitals have seldom been described. More prominent dermoscopic features seem to be blue-gray ovoid nests and arborizing vessels associated with whitish structureless areas. SCC and Bowen's disease (BD) - a variant of in situ SCC - may be encountered in the genital area and are sometimes associated with human papillomavirus (HPV) infection. Pigmented SCC is very rare, and most of the literature is focused on pigmented BD (pBD), which is mainly characterized by gray-brown dots in a linear fashion and glomerular vessels without evident scales. In conclusion, pNMSC is rarely encountered on genitals; evaluation with dermoscopy or other ancillary devices like RCM is important both to exclude benign lesions like seborrheic keratosis and lentigo and to rule out melanoma.

P32 Melanin confers protection against ultraviolet radiation-mediated mitochondrial DNA damage in skin of colour

Abstract Introduction and aims Melanin is a photoprotective pigment that effectively absorbs and scatters solar ultraviolet radiation (UVR) affording protection against nuclear DNA photodamage. In lightly pigmented skin, UVR-mediated damage of cellular DNA is not limited to nuclear DNA; mitochondrial DNA (mtDNA) is also susceptible to UVR-induced damage leading to an increased frequency of deletions and mutations. However, the protective role of melanin against UVR-induced mtDNA damage is unknown. Therefore, we sought to determine whether melanin affords protection against UVR-induced mtDNA damage. Methods Using Genome Analysis Toolkit best practices, mtDNA was extracted from photoexposed forearm and photoprotected buttock of Black African (n = 3) and White Northern European (n = 3) volunteers and sequenced to identify somatic mutations. Results Comparison of photoexposed forearm with photoprotected buttock identified a total of 21 somatic mutations, including single-nucleotide transitions, deletions and additions. Of these, three somatic mutations were observed in Black skin, whereas 18 were identified in White skin (P < 0.01). Analysis of single-nucleotide transitions revealed a total of 13 variations and of these, two were identified in Black skin and 11 in White skin. Interestingly, of the somatic mutations observed in White skin, there was enrichment of the cytosine to thymine (C>T) transitions in all volunteers. In contrast, photoexposed Black skin had a thymine to guanine transition at position 414 (T414G) identified for two of the three Black volunteers. Conclusions Here we identified that Black skin exhibited fewer mtDNA mutations compared with White skin; enrichment of C>T transitions in White skin is consistent with a previously reported UVR-signature of mtDNA damage, whereas the T414G transition identified in Black photoexposed skin has previously been suggested as a mitochondrial biomarker of photoageing. Our study suggests that melanin confers protection against UVR-mediated mtDNA damage and that the mtDNA damage signature differs between skin types.

Efficacy of imiquimod in the management of lentigo maligna.

Lentigo maligna (LM) is a melanocytic proliferation occurring on photo-exposed skin that may progress to LM melanoma. Surgery is recommended as first-line treatment. Excision margins of 5-10 mm remain, without international consensus. Several studies have shown that imiquimod, an immunomodulator, induces LM regression. This study investigated the effect of imiquimod versus placebo in neoadjuvant settings. We performed a prospective, randomized, multicentre, phase III clinical study. Patients were randomly assigned in 1:1 ratio to receive imiquimod or placebo for 4 weeks, followed by LM excision 4 weeks after the last application of imiquimod or placebo. The primary endpoint was extra-lesional excision, with a 5 mm margin from the residual pigmentation after imiquimod or vehicle. Secondary endpoints included the gain on the surface removed between the two groups; number of revision surgeries to obtain extra-lesional excisions; relapse-free time; and number of complete remissions after treatment. A total of 283 patients participated in this study; 247 patients, 121 patients in the placebo group and 126 in the imiquimod group, accounted for the modified ITT population. The first extralesional extirpation was performed in 116 (92%) imiquimod patients and in 102 (84%) placebo patients; the difference was not significant (p = 0.0743). Regarding the surface of LM, imiquimod reduced the LM surface (4.6-3.1 cm2 ) significantly (p < 0.001) more compared to the placebo (3.9-4.1 cm2 ). Imiquimod reduces the lentigo maligna surface after 1 month of treatment, without a higher risk of intralesional excision and with a positive aesthetic outcome.

Quantitative morphometric analysis of intrinsic and extrinsic skin ageing in individuals with Fitzpatrick skin types II-III.

Skin ageing is an intricate physiological process affected by intrinsic and extrinsic factors. There is a demand to understand how the skin changes with age and photoexposure in individuals with Fitzpatrick skin types I-III due to accelerated photoageing and the risk of cutaneous malignancies. To assess the structural impact of intrinsic and extrinsic ageing, we analysed 14 skin parameters from the photoprotected buttock and photoexposed dorsal forearm of young and ageing females with Fitzpatrick skin types II-III (n=20) using histomorphic techniques. Whilst the minimum viable epidermis (Emin ) remained constant (Q > 0.05), the maximum viable epidermis (Emax ) was decreased by both age and photoexposure (Q ≤ 0.05), which suggests that differences in epidermal thickness are attributed to changes in the dermal-epidermal junction (DEJ). Changes in Emax were not affected by epidermal cell proliferation. For the first time, we investigated the basal keratinocyte morphology with age and photoexposure. Basal keratinocytes had an increased cell size, cellular height and a more columnar phenotype in photoexposed sites of young and ageing individuals (Q ≤ 0.05), however no significant differences were observed with age. Some of the most striking changes were observed in the DEJ, and a decrease in the interdigitation index was observed with both age and photoexposure (Q ≤ 0.001), accompanied by a decreased height of rête ridges and dermal papilla. Interestingly, young photoexposed skin was comparable to ageing skin across many parameters, and we hypothesise that this is due to accelerated photoageing. This study highlights the importance of skin care education and photoprotection from an early age.

Strategies for Metabolomic Analysis of Damaged Skin from Cell and Tissue Samples Using Gas Chromatography-Mass Spectrometry

Metabolomics can provide a readout of the biochemical and physiological state of a biological system. Gas chromatography coupled to mass spectrometry (GC-MS) has been widely applied for metabolomic analysis due to its numerous advantages, such as good sensitivity, high resolution, reproducibility, extensive database, lower acquisition cost and greater coverage. In addition, combined with efficient methods of sampling and sample preparation, the metabolomic analysis of damaged skin based on GC-MS can provide an important step toward elucidating several skin diseases. Based on this, this review presents a comprehensive overview of sampling, sample preparation, data processing and GC-MS analysis of metabolomic studies of damaged skin. Also, part of the biological interpretation of metabolites such as cis- and trans-urocanic acid (UCA) altered in photoexposed skin and lauric acid (C12:0) and palmitic acid (C16:0) in melanoma is discussed. Finally, to improve decision-making, a part of the integration of skin metabolomics with other omics sciences for the advancement of diagnosis is presented.

Early onset of senescence and imbalanced epidermal homeostasis across the decades in photoexposed human skin: Fingerprints of inflammaging.

Inflammaging is a theory of ageing which purports that low-level chronic inflammation leads to cellular dysfunction and premature ageing of surrounding tissue. Skin is susceptible to inflammaging because it is the first line of defence from the environment, particularly solar radiation. To better understand the impact of ageing and photoexposure on epidermal biology, we performed a system biology-based analysis of photoexposed face and arm, and photoprotected buttock sites, from women between the ages of 20s to 70s. Biopsies were analysed by histology, transcriptomics, and proteomics and skin surface biomarkers collected from tape strips. We identified morphological changes with age of epidermal thinning, rete ridge pathlength loss and stratum corneum thickening. The SASP biomarkers IL-8 and IL-1RA/IL1-α were consistently elevated in face across age and cis/trans-urocanic acid were elevated in arms and face with age. In older arms, the DNA damage response biomarker 53BP1 showed higher puncti numbers in basal layers and epigenetic ageing were accelerated. Genes associated with differentiation and senescence showed increasing expression in the 30s whereas genes associated with hypoxia and glycolysis increased in the 50's. Proteomics comparing 60's vs 20's confirmed elevated levels of differentiation and glycolytic-related proteins. Representative immunostaining for proteins of differentiation, senescence and oxygen sensing/hypoxia showed similar relationships. This system biology-based analysis provides a body of evidence that young photoexposed skin is undergoing inflammaging. We propose the presence of chronic inflammation in young skin contributes to an imbalance of epidermal homeostasis that leads to a prematurely aged appearance during later life.

LB901 Inflammaging in human skin: Early onset of senescence and imbalanced epidermal homeostasis across the decades

Inflammaging is a theory which purports that chronic inflammation leads to cellular dysfunction and premature aging of tissue. Skin is susceptible to inflammaging because it is the first line of defense from the environment and can be heightened in photoexposed skin. To better understand the impact of aging and photoexposure on epidermal biology we performed a systems biology-based analysis of photoexposed and protected sites from women between ages of 20’s to 70’s. Biopsies were analyzed by histology, transcriptomics, proteomics, and biomarkers from tape strips.

The influence of MC1R ondermal morphological features of photo-exposed skin in women revealed by reflectance confocal microscopy and optical coherence tomography.

The melanocortin 1 receptor (MC1R) gene is one of the major determinants of skin pigmentation. It is a highly polymorphic gene and some of its polymorphisms have been related to specific skin phenotypes, increased risk of skin cancers and skin photoageing. Currently, its contribution to changes in dermal features in photo-exposed skin is unknown. The main objective of this study is to evaluate the potential correlation between MC1R status and specific healthy photo-exposed skin characteristics. Skin facial features were estimated by evaluation with standard digital photography with automated featurescount, reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) in 100 healthy women. Skin of the forearms was used as a control. The study found an association between RHC MC1R polymorphisms and dermal features in photo-exposed areas being represented by increased vessel density and pixel density in OCT (P=.025 and P=.001, respectively) and increased coarse collagen in RCM (P=.034), as compared to non-RHC subjects. To our knowledge this is previously unreported. Additionally, previously reported correlations between light hair colour and pigmented spots with MC1R RHC polymorphisms have been confirmed. Our results suggest the role of RHC MC1R variants in dermal variations of facial skin, as compared to non-RHC variants. To our knowledge this is previously unreported.

Au-delà des kératoses actiniques, le champ de cancérisation cutané

Lesions occurring in actinic keratoses (AK) form erythematous, squamous, crusty and keratotic papules that appear on skin chronically exposed to the sun due to ultraviolet radiation. They are formed by the proliferation of atypical keratinocytes limited to the epidermis and may progress to squamous cell carcinoma in situ and to cutaneous squamous cell carcinoma (CEC). Although low, the metastatic risk associated with the CEC is not negligible. The concept of field cancerization was introduced in 1953following studies of neoplastic lesions of the oral mucosa. A cancer field is a normal-looking pre-tumoral zone with subclinical, multifocal anomalies, which may constitute a base for new neoplastic lesions. Such fields are frequently seen in areas of photo-exposed skin and around the edges of AK and CEC. In this event, treatment should not be limited to visible or palpable AK lesions, and if a cancer field is suspected, treatment involving the physical destruction or elimination of atypical keratinocytes from the entire area should be considered. Such an approach may improve the long-term prognosis, reduce treatment costs and ensure optimal cosmetic outcome.

Photodynamic therapy corrects abnormal cancer-associated gene expression observed in actinic keratosis lesions and induces a remodeling effect in photodamaged skin

BackgroundActinic keratoses (AK) are proliferations of neoplastic keratinocytes in the epidermis resulting from cumulative exposure to ultraviolet radiation (UVR), which are liable to transform into squamous cell carcinoma (SCC). Organ Transplant Recipients (OTR) have an increased risk of developing SCC as a consequence of long-term immunosuppressive therapy. The aim of this study was to determine the molecular signature of AKs from OTR prior to treatment with methyl aminolevulinate-photodynamic therapy (MAL-PDT), and to assess what impact the treatment has on promoting remodeling of the photo-damaged skin. MethodsSeven patients were enrolled on a clinical trial to assess the effect of MAL-PDT with biopsies taken at screening prior to the first treatment session (week 1), and six weeks after completion of final treatment (week 18). Whole-genome gene expression analysis was carried out on skin biopsies isolated from an AK lesion, an area surrounding the lesion, and a non-sun exposed region of the body. Quantitative PCR was utilized to confirm the differential expression of key genes. ResultsMAL-PDT treatment corrected abnormal proliferation-related gene profiles, corrected aberrantly expressed cancer-associated genes and induced expression of dermal extracellular matrix genes in photo-exposed skin. ConclusionThe efficacy of the MAL-PDT on AK lesions was confirmed at whole-genome gene expression level. A transcriptional signature of remodeling, identified through assessing the effect of MAL-PDT on photodamaged skin, supports the use of MAL-PDT for treating photodamaged skin and field cancerized areas.

Reduction of hyaluronan and increased expression of HYBID (alias CEMIP and KIAA1199) correlate with clinical symptoms in photoaged skin

Hyaluronan (HA) metabolism in skin fibroblasts is mediated by HYBID (hyaluronan binding protein involved in hyaluronan depolymerization, alias CEMIP and KIAA1199) and the HA synthases HAS1 and HAS2. However, photoageing-dependent changes in HA and their molecular mechanisms, and the relationship between HA metabolism and clinical symptoms in photoaged skin remain elusive. We examined the amount, size and tissue distribution of HA and expression levels of HYBID, HAS1 and HAS2 in photoaged skin, and analysed their relationship with the degree of photoageing. Photoageing-dependent changes of HA were investigated by studying skin biopsies isolated from photoprotected and photoexposed areas of the same donors, and the relationships between HA and photoageing symptoms such as skin wrinkling and sagging were examined. Skin biopsy specimens showed that the amount and size of HA are decreased in photoexposed skin compared with photoprotected skin, and this was accompanied by increased expression of HYBID and decreased expression of HAS1 and HAS2. Histologically, HA staining in the papillary dermis was decreased in photoexposed skin, showing reverse correlation with HYBID expression. HYBID expression in the photoexposed skin directly correlated with skin roughness and sagging parameters, and the reduced HA staining in the papillary dermis in the photoexposed skin positively correlated with these symptoms. These data demonstrate that imbalance between HYBID-mediated HA degradation and HAS-mediated HA synthesis may contribute to enhanced HA catabolism in photoaged skin, and suggest that HYBID-mediated HA reduction in the papillary dermis is related to skin wrinkling and sagging of photoaged skin.

Cutaneous infiltration of plasmacytoid dendritic cells and T regulatory cells in skin lesions of polymorphic light eruption.

Polymorphic light eruption (PLE) is the most common autoimmune photodermatosis. Plasmacytoid dendritic cells (PDCs) are important mediators of innate antimicrobial immunity involved in the pathogenesis of many inflammatory skin diseases. In addition to PDCs, regulatory T cells (Tregs) are involved in controlling inflammation and adaptive immunity in skin by their immunosuppressive capacity. The aim of this study was to investigate the presence of PDCs and Tregs in photoexposed skin from PLE compared to healthy skin. Patients with PLE diagnosis and healthy controls were recruited and underwent a photoprovocative test. A 4-mm punch biopsy was taken from the site of positive photoprovocation test reaction, and immunohistochemistry for BDCA2 as marker for PDCs, CD4 and FOXP3 as markers for Tregs was performed. Double immunostain for FOXP3 and CD4 was performed as well. Absolute counts for CD4, BDCA2 and FOXP3 were performed in at least 5 High Power Fields (HPF). Percentage of CD4-, BDCA2- and CD4FOXP3-positive cells over the total inflammatory infiltrate was assessed for each case. We enrolled 23 patients and controls. BDCA2+ cells were present in 91.3% of PLE skin samples and 100% of healthy volunteer. Both in PLE patients and healthy controls, PDCs distribution was mainly dermic (P < 0.05). Compared to healthy controls, both epidermic and dermic BDCA2+ cells count were significantly higher in PLE patients (P < 0.05). Both in PLE patients and healthy controls, Tregs distribution was mainly dermic (P < 0.05). The presence of both CD4+ cells and FOXP3+ cells was significantly higher in the dermis of PLE patients compared to controls (P < 0.05). Relative percentages of cellular infiltrations confirmed these results. D-PDCS and Tregs may play a significant role in the development of PLE, and dermal distribution of PDCs in PLE skin biopsies seems to confirm a possible overlap with cutaneous lupus erythematosus (CLE).

Does hypothyroidism augment sun-induced skin damage?

ABSTRACTObjectives: We investigated the mutual effects of overt hypothyroidism and prolonged sunlight exposure on free radical accumulation and oxidative skin damage.Methods: Free radical accumulation was evaluated by monitoring the transformation of 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) into MTT-formazan. The pro-oxidant enzymes xanthine oxidase (XO) and NADPH-diaphorase were measured in the skin. XO activity was estimated based on the yield of uric acid, while NADPH-diaphorase reactivity was monitored histochemically as an indirect marker of nitric oxide synthase and nitric oxide activity. Cellular damage was determined by malondialdehyde formation, a marker for lipid peroxidation.Results: In the skin of both euthyroid and hypothyroid animals, solar simulated ultraviolet irradiance increased the activity of XO and the NADPHdiaphorase reactivity as a protective response to formation of free radicals, such as reactive oxygen or nitrogen species. These pro-oxidant enzymes diminished in hypothyroid rats. Accumulation of the same amount of free radicals led to similar peroxidation in both hypothyroid and irradiated euthyroid rats. Hypothyroid skin after UV-exposure showed even greater lipid peroxidation.Discussion: The hypothyroid state could be a risk factor for enhanced oxidative skin damage in chronic photo-exposed skin due to oxidative stress. The lipid peroxidation is one of the major pathways by which photo-oxidative stress promotes photocarcinogenesis and photo-aging.

In vivo confocal Raman spectroscopy for intrinsic aging and photoaging assessment

BackgroundIn vivo confocal Raman spectroscopy is a non-invasive method to assess either the epidermis or the dermis composition. Few studies have focused on dermis collagen alterations through intrinsic aging and photoaging. ObjectiveThis study evaluated the in vivo Raman spectra from the dermis of a photoexposed site versus a non-photoexposed region in different age groups, and evaluated the correlation between peak intensities and age, photoaging score and the amount of collagen assessed with histology and high frequency ultrasound (HFUS). MethodsFifteen volunteers aged 28–82 years were divided into three groups according to forearm photoaging degree. In vivo Raman spectra from the dermis were collected on the dorsal forearm (chronically photoexposed skin) and on the proximal medial arm (non-photoexposed skin). Cross-sectional images of the skin were obtained using a 20MHz ultrasound unit exactly on the same sites, which were further submitted to punch biopsies for histologic study (collagen I immunohistochemistry, picrosirius red staining and Verhoeff). Principal Component Analysis (PCA) and Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) were taken in the spectral region of 796cm−1–996cm−1 to determine its potential to discriminate between different groups. The Spearman rank correlation coefficient of individual peak intensities and ratios with age, clinical score and the amount of collagen assessed by ultrasound and histology were calculated. ResultsPCA of pairs of groups and OPLS-DA could discriminate the intrinsically from the photoaged skin and the young group from the elderly one, with important contribution of the 938cm−1 and 855cm−1 peaks intensities. The intensity of the peaks in 855cm−1 and/or 938cm−1 presented moderate correlation with age (rho=0.579, p=0.049) and moderate to high inverse correlation with HFUS echogenicity (rho=−0.710, p=0.010) and collagen I immunohistochemistry (rho=−0.833, p=0.005) in the non-photoexposed region. The I1275/I1450 intensities ratio presented moderate to high correlation coefficients with age (rho=−0.730, p=0.007), photoaging score (rho=−0.594, p=0.042), HFUS echogenicity (rho=0.760, p<0.001) and histology (collagen I immunohistochemistry (rho=0.643, p=0.024), picrosirius (rho=0.773, p=0.005) and Verhoeff (rho=−0.727, p=0.011)) in the photoexposed site. ConclusionThe wavenumber region between 798 and 994cm−1 is useful for the analysis of dermal collagen alterations through the intrinsic aging process, while photoaging is better assessed by the I1275/I1450 intensities ratio. This is the first skin aging study to show a correlation between Raman peaks and the amount of collagen assessed by HFUS and histology.

Indole 3-acetic acid-photodynamic therapy in the treatment of multiple actinic keratoses: A proof of concept pilot study

BackgroundActinic Keratoses (AK) are considered a form of in situ Squamous Cell Carcinoma (SCC) arising on chronically photoexposed skin. PDT with ALA or MAL is an effective treatment for multiple AK due its high Overall Response Ratio (ORR) but is burdened by important drawbacks: time-consumption, pain and high costs. Indole-3 acetic acid (IAA) is a newly described photosensitizer with proven clinical efficacy on seborrheic dermatitis and acne vulgaris. The aim of the study was to assess efficacy, safety and tolerability of a cycle of IAA-PDT at 0.015% in liposomal gel in the treatment of multiple AK of face or scalp. MethodsWe treated 12 patients affected by multiple AK on face/scalp with 4 weekly applications. The product was applied for 15min under occlusion; medicated area was then irradiated for 15min with a LED light at 520nm wavelength for a total fluency of 9J/cm2. ResultsNo grade 3/4 SAE have been reported; all 12 patients successfully completed the cycle. CR at 3 months follow-up was 25%, with an ORR of 50%. Patients reported almost no pain during irradiations, with mean overall Visual Analogic Scale (VAS) score of 0.3±0.7. IAA-PDT led to a significant improve on Disease Life Quality Index (DLQI) mean score, but no variations on Actinic Keratosis Quality of Life (AKQoL) mean score. ConclusionsAlthough larger studies are needed, this is a first “proof of concept” of IAA- PDT as a possible treatment for multiple AK on face/scalp.

Pigmented macules of bony prominences (PMBP): A distinct presentation in patients with red hair

To the Editor: Besides the usual presentation of ephelides, we noticed in some fair-skinned patients the presence of pigmented macules of bony prominences (PMBP). Although most of them presented with facial ephelides and have red hair, these patients harbored a very distinctive clinical presentation, with pigmented macules suggestive of ephelides but restricted to bony prominences and sparing the classic photo-exposed skin. We conducted a multicentered observational study to better characterize this entity. Consecutive patients with red hair older than 3 years seen in 7 centers between November 2013 and June 2014 were included. Informed oral consent was obtained from all patients before entering the trial (institutional review board approval waived). Parental consent was obtained for those younger than 18 years old. Epidemiologic and clinical features of patients with and without PMBP were analyzed. When PMBP were present, photographs were taken and dermoscopy examination performed. One patient also had a skin biopsy specimen taken of a macule on his elbow. Fifty patients with phototype II to VI, older than 3 years and seen in the outpatient Department of Dermatology of the University Hospital of Nice, France, served as control subjects. For statistical analysis, patients with PMBP were compared with patients without pigmented macules. The χ2, exact Fisher, and Student t test were used when appropriate. In all, 38 patients were included and 17 (44.7%) had PMBP (Table I). Whereas ephelides were localized only in sun-exposed areas, with the heaviest concentration on face, upper aspect of the back, and back of forearm, PMBP were located mainly on the elbows (87.5%), knees (81.2%), and back of the hands (43.8%). Strikingly, lesions were restricted to bony prominences and spared the rest of the hands and limbs (Fig 1). One patient had macules on the buttocks, a region typically spared by ultraviolet light. The majority of patients had macules in more than 1 bony prominence (87.5%), with identical features in all sites: buff to light-brown macules of 1 to 3 mm. No triggering factor (including topical treatment) except repeated friction could be found. The group with PMBP had significantly fewer ephelides compared with the group without PMBP (P = .03, P = .04, and P = .01 for the lower aspect of neck, upper limbs, and other areas such as lower limbs and back, respectively). Dermoscopy showed light-brown macules with uniform pigmentation and “moth-eaten” edges without sign of melanocytic nevus. Histology showed a normal epidermis with some basal keratinocytes overloaded by melanin pigment without an increase in melanocytosis, some melanophages in the papillary dermis, and a discreet superficial nonspecific perivascular lymphocytic infiltrate. Half of the 6 other family members seen at the consultation had PMBP suggesting a familial predisposition.Table ICharacteristic of patients with red hair: Comparison of the groups with and without pigmented macules of bony prominencesWith PMBPWithout PMBPPAge, y, mean17.220.95.39Male to female ratio1.831.62.85Tanning.34 None5/15 (33.3%)8/21 (38.1%) Light8/15 (60%)13/21 (61.9%) Dark1/15 (6.7%)0/21 (0%)Eye color.66 Blue3/16 (18.8%)5/21 (23.8%) Green2/16 (12.5%)5/21 (23.8%) Brown11/16 (68.8%)11/21 (52.4%)Shade of hair.8 Venetian0/16 (0%)1/21 (4.8%) Ginger12/16 (76.5%)17/21 (80.95%) Auburn3/16 (17.6%)3/21 (14.3%) Mix1/16 (5.9%)0/21 (0%)Ephelides location Face15/16 (93.75%)15/19 (78.95%).35 Lower neck3/15 (20%)11/19 (57.9%).03∗Difference between both groups statistically significant (P < .05). Upper limbs5/15 (33.3%)13/19 (68.4%).04∗Difference between both groups statistically significant (P < .05). Others1/15 (6.67%)10/19 (52.6%).01∗Difference between both groups statistically significant (P < .05).Topical treatments0/12 (0%)8/20 (40%).03∗Difference between both groups statistically significant (P < .05).Sun exposure.54 Never3/10 (30%)3/19 (15.79%) Occasionally3/10 (30%)10/19 (52.6%) Often4/10 (40%)6/19 (31.58%) Always0/10 (0%)0/19 (0%)Photoprotection.56 Never1/10 (10%)0/19 (0%) Occasionally1/10 (10%)4/19 (21.05%) Regularly1/10 (10%)3/19 (15.79%) Always7/10 (70%)12/19 (63.16%)Parent skin type Father.27I-II0/7 (0%)5/16 (31.25%)III-IV7/7 (100%)11/16 (66.75%)V-VI0/7 (0%)0/16 (0%) Mother.67I-II5/9 (55.6%)7/16 (43.75%)III-IV4/9 (44.4%)9/16 (56.25%)V-VI0/9 (0%)0/16 (0%)PMBP, Pigmented macules of bony prominences.∗ Difference between both groups statistically significant (P < .05). Open table in a new tab PMBP, Pigmented macules of bony prominences. In the control group (mean age 14.48 years, male to female ratio: 1.08), 32 patients (64%) had phototype III or IV, 11 patients (22%) had phototype II, and 7 patients (14%) had phototype V or VI skin. None of them had PMBP, while 9 of them had ephelides (P < .0001). We describe a distinctive clinical presentation of pigmented macules in individuals with red hair localized on bony prominences. This clinical presentation is distinct from the usual presentation of ephelides. Repeated frictions in individuals with predisposed genetic background is suspected to be the causative factor, but further investigations are now required to better understand the pathophysiology and the potential prognostic value of such lesions. The authors are indebted to Alexandra Charlesworth for language editing.

Basal Cell Carcinoma in Gorlin’s Patients: a Matter of Fibroblasts-Led Protumoral Microenvironment?

Basal cell carcinoma (BCC) is the commonest tumor in human. About 70% sporadic BCCs bear somatic mutations in the PATCHED1 tumor suppressor gene which encodes the receptor for the Sonic Hedgehog morphogen (SHH). PATCHED1 germinal mutations are associated with the dominant Nevoid Basal Cell Carcinoma Syndrome (NBCCS), a major hallmark of which is a high susceptibility to BCCs. Although the vast majority of sporadic BCCs arises exclusively in sun exposed skin areas, 40 to 50% BCCs from NBCCS patients develop in non photo-exposed skin. Since overwhelming evidences indicate that microenvironment may both be modified by- and influence the- epithelial tumor, we hypothesized that NBCCS fibroblasts could contribute to BCCs in NBCCS patients, notably those developing in non photo-exposed skin areas. The functional impact of NBCCS fibroblasts was then assessed in organotypic skin cultures with control keratinocytes. Onset of epidermal differentiation was delayed in the presence of primary NBCCS fibroblasts. Unexpectedly, keratinocyte proliferation was severely reduced and showed high levels of nuclear P53 in both organotypic skin cultures and in fibroblast-led conditioning experiments. However, in spite of increased levels of senescence associated β-galactosidase activity in keratinocytes cultured in the presence of medium conditioned by NBCCS fibroblasts, we failed to observe activation of P16 and P21 and then of bona fide features of senescence. Constitutive extinction of P53 in WT keratinocytes resulted in an invasive phenotype in the presence of NBCCS fibroblasts. Finally, we found that expression of SHH was limited to fibroblasts but was dependent on the presence of keratinocytes. Inhibition of SHH binding resulted in improved epidermal morphogenesis. Altogether, these data suggest that the repertoire of diffusible factors (including SHH) expressed by primary NBCCS fibroblasts generate a stress affecting keratinocytes behavior and epidermal homeostasis. Our findings suggest that defects in dermo/epidermal interactions could contribute to BCC susceptibility in NBCCS patients.

Reliable assessment of forearm photoageing by high-frequency ultrasound: a cross-sectional study.

High-frequency ultrasound is a non-invasive tool used in skin ageing research to assess dermis thickness and echogenicity. This study evaluated the reliability of a range of high-frequency ultrasound parameters and tested their correlation with age and a validated clinical scale for the assessment of forearm skin photoageing; the difference between two body sites according to environmental exposition patterns was also investigated. Twenty-three volunteers aged 28-82 years were divided into three groups according to forearm photoageing degree. A 20 MHz ultrasound unit was used to obtain cross-sectional images of the skin by two trained investigators on two different sites: the dorsal forearm (chronically photoexposed skin) and the proximal medial arm (non-photoexposed skin). Several echogenicity parameters were studied for each skin compartment: total dermis, upper dermis and lower dermis, and the ratio between upper and lower dermis. The intraclass correlation coefficient (for complete agreement) between investigators was higher for upper and total dermis echogenicity measures compared with the lower dermis. At the non-photoexposed site, the upper and lower dermis parameter ratio was better correlated with age. At the photoexposed area, total dermis parameters demonstrated higher correlations with clinical score. The authors discuss the choice of parameters for forearm photoageing assessment using high-frequency ultrasound.

Differential levels of elastin fibers and TGF-β signaling in the skin of Caucasians and African Americans

BackgroundWhile skin color is the most notable difference among ethnic skins the current knowledge on skin physiological and aging properties are based mainly on Caucasian skin studies. ObjectiveTo evaluate histological differences in elastin fiber network and differential responsiveness to TGF-β in skin of Caucasians and African Americans. MethodsThese studies were undertaken using human skin biopsies, primary dermal fibroblasts, Western blot analyses, immunofluorescence microscopy, cDNA array and quantitative real-time PCR. ResultsIn Caucasian subjects, tropoelastin expression and elastin fibers in photoprotected skin was substantially less than in age-matched African American skin. Expression of tropoelastin in photoexposed skin of African American was similar to their photoprotected skin, suggesting that photoexposure did not affect elastin fibers in African American skin to the same extent as Caucasian skin. An elevated level of TGF-β1 present in media from dermal fibroblasts derived from African American skins correlated well with the higher levels of TGF-β mRNA in African American skins analyzed by cDNA array. Treatment with TGF-β1 resulted in a considerably higher induction of elastin mRNA in dermal fibroblasts from African Americans than from Caucasian fibroblasts, indicative of enhanced TGF-β signaling in African American skins. Furthermore, UVA exposure decreased levels of elastin mRNA in Caucasian fibroblasts compared to African Americans fibroblasts. ConclusionThese results suggest that there are ethnic differences in the elastin fiber network and in TGF-β signaling in African American and Caucasian skin, and that African American have less UV dependent loss of elastin than Caucasian which may contribute to the different perceived aging phenotypes.