To Control Site-Specific Skin Gene Expression, Autocrine Mimics Paracrine Canonical Wnt Signaling and Is Activated Ectopically in Skin Disease.

Despite similar components, the heterogeneity of skin characteristics across the human body is enormous. It is classically believed that site-specific fibroblasts in the dermis control postnatal skin identity by modulating the behavior of the surface-overlying keratinocytes in the epidermis. To begin testing this hypothesis, we characterized the gene expression differences between volar (ventral; palmoplantar) and nonvolar (dorsal) human skin. We show that KERATIN 9 (KRT9) is the most uniquely enriched transcript in volar skin, consistent with its etiology in genetic diseases of the palms and soles. In addition, ectopic KRT9 expression is selectively activated by volar fibroblasts. However, KRT9 expression occurs in the absence of all fibroblasts, although not to the maximal levels induced by fibroblasts. Through gain-of-function and loss-of-function experiments, we demonstrate that the mechanism is through overlapping paracrine or autocrine canonical WNT-ß-catenin signaling in each respective context. Finally, as an in vivo example of ectopic expression of KRT9 independent of volar fibroblasts, we demonstrate that in the human skin disease lichen simplex chronicus, WNT5a and KRT9 are robustly activated outside of volar sites. These results highlight the complexities of site-specific gene expression and its disruption in skin disease.

Morphological and molecular characterization of actinic lentigos reveals alterations of the dermal extracellular matrix.

BACKGROUND: Actinic lentigos (AL) are benign hyperpigmented skin lesions associated with photoageing. Despite their high prevalence, biological mechanisms driving their formation remain unclear. OBJECTIVES: To provide new insights about the physiopathology of AL through a comprehensive description of their histological and molecular features. METHODS: Quantitative analysis of dermoscopic images was used to select AL containing elongated patterns, predicted to display a highly deformed dermal-epidermal junction (DEJ), on the back of the hands of 15 Caucasian women. Biopsies from lesional and adjacent nonlesional (NL) areas were processed for histological analysis or gene expression profiling. RESULTS: Histological staining confirmed a drastic deformation of the DEJ in AL, with deep epidermal invaginations into the dermis. Although the melanin content was significantly higher in AL compared with NL epidermis, the distribution of melanocytes along the DEJ was unchanged. Transcriptomic analysis revealed a signature of 529 genes differently expressed in AL vs. NL skin. Alteration of epidermal homeostasis was confirmed by the dysregulation of keratinocyte proliferation and differentiation markers. Surprisingly, canonical genes involved in melanogenesis were not significantly modulated in AL. A striking finding was the overexpression of a large group of genes involved in dermal extracellular matrix organization and remodelling. Dermal alterations were confirmed by immunolabellings on AL and NL sections. CONCLUSIONS: Drastic disorganization of the cutaneous structure in AL is accompanied by a specific molecular signature revealing alterations in both epidermal and dermal compartments. In particular, our results suggest that local modifications of the dermal extracellular matrix might contribute to hyperpigmentation in AL.

Impact of systemic alitretinoin treatment on skin barrier gene and protein expression in patients with chronic hand eczema.

BACKGROUND: Chronic hand eczema (CHE) is a common inflammatory skin disease that affects approximately 10% of the population. Systemic alitretinoin has been shown to be effective in patients with CHE who are refractory to topical corticosteroids. OBJECTIVES: To analyse the impact of alitretinoin on the skin barrier genes and protein expression in the skin lesions of patients with CHE. MATERIALS AND METHODS: Fifteen patients with CHE were treated with 30 mg daily of alitretinoin for up to 27 weeks. Disease severity was assessed using a clinical score. Skin biopsies from all the patients were evaluated before and after therapy for the expression of Ki-67, various skin barrier genes and thymic stromal lymphopoietin (TSLP) by real-time quantitative polymerase chain reaction and immunohistochemistry. RESULTS: After alitretinoin application, an improvement in the clinical severity of CHE was observed in the majority of patients. Analysis of skin biopsies before treatment showed a significant increase in Ki-67-positive cells in the suprabasal layer and a dysregulated expression of various skin barrier genes, such as claudin 1, loricrin, filaggrin and cytokeratin 10, which were normalized after treatment. TSLP was significantly upregulated in patients with CHE and also normalized after alitretinoin treatment and negatively correlated with filaggrin. CONCLUSIONS: Our data indicate that the expression of barrier genes and proteins was normalized following treatment with alitretinoin in patients with CHE. The change in expression levels of these genes correlated with the clinical efficacy, suggesting that alitretinoin exhibits a disease-modifying activity. TSLP is upregulated in CHE and seems to counteract filaggrin expression in the skin.

Hand eczema and stratum corneum ceramides.

BACKGROUND: Hand eczema (HE) is a multifactorial disease, comprising different aetiological conditions and different morphologies. There are two aetiologically distinct groups of HE recognised: exogenous, such as contact dermatitis (allergic and/or irritant HE) and endogenous, such as the classic hyperkeratotic HE. Differences in the skin barrier properties of these two conditions could theoretically be expected. AIM: To examine whether differences exist in the lipid profile and the susceptibility of the stratum corneum (SC) in patients with allergic/irritant HE and those with hyperkeratotic HE. METHODS: Using cyanoacrylate, SC samples were taken from 23 patients with allergic/irritant HE and 15 with hyperkeratotic HE for lipid analysis by high-performance thin-layer chromatography (HPTLC). Samples were also taken from adjacent, unaffected skin. Severity of HE was assessed by the Hand Eczema Severity Index (HECSI), and skin barrier susceptibility was assessed by measuring transepidermal water loss (TEWL) after a 24-hour patch test with sodium lauryl sulfate (SLS). RESULTS: No statistically significant difference was found between groups for the lipid analysis or for skin susceptibility to SLS. We found a significantly higher HECSI score for hyperkeratotic HE compared with irritant or allergic HE (P = 0.02). CONCLUSIONS: There appears to be no difference in skin barrier between allergic/irritant HE (exogenous eczema) and hyperkeratotic HE (endogenous eczema) with regard to SC lipids or susceptibility to SLS.

Pseudoporphyria following self-medication with chlorophyll.

Two cases of pseudoporphyria are described in which the clinical features of porphyria cutanea tarda occurred in the absence of abnormalities in porphyrin metabolism. Both patients presented with skin fragility and bullae on the dorsal aspect of the hands. The patients consumed a commercial liquid chlorophyll drink in which we detected fluorescent compounds with characteristics typical of previously described chlorophyll derived photosensitisers.

The diagnostic value of fungal fluorescence in onychomycosis.

BACKGROUND: Fluorescence of pathogenic fungi has been previously shown when hematoxylin and eosin-stained sections are examined under a fluorescent microscope. We hypothesize that this phenomenon could aid in the evaluation of nail specimens for onychomycosis. METHODS: Forty-eight routinely stained nail sections of periodic acid-Schiff (PAS)-positive onychomycosis, along with 23 PAS-negative control specimens with a clinical diagnosis of onychomycosis, were studied under a fluorescent microscope to determine the clinical usefulness of this technique. RESULTS: In most cases, fluorescence of fungal organisms was noted. Fungi were identified by their tubular or annular shapes with fluorescence surrounding them. The sensitivity and specificity of the method were 96 and 90%, respectively. In some cases, it was difficult to identify the fungi because of the relative paucity of organisms, weak fluorescence and high background fluorescence of eosinophilic nail keratin. CONCLUSIONS: We conclude that fluorescence microscopy can be used as a rapid screening tool for identification of fungi in nail specimens.

Circumscribed palmar or plantar hypokeratosis: first report on a nonacral site with unique histologic features.

Circumscribed palmar or plantar hypokeratosis was first described by Pérez et al in 2002 as a unique entity of the skin in which they reported 10 patients who presented with well-circumscribed areas of erythematous depressed or eroded skin mostly over the thenar or hypothenar eminences of the palms and less commonly on the soles. Histologically, the lesions demonstrated an abrupt drop-off in the cornified layer resulting in a broad area of hypokeratosis. Pérez et al hypothesized that these lesions were a distinctive epidermal malformation. There have been several reports since, some of which implicate trauma as an etiologic agent; however, the exact etiology remains unclear. The authors present the first case of circumscribed palmar or plantar hypokeratosis on a nonacral site (chest of a 63-year-old man) with novel histological features, including granular parakeratosis and evidence of trauma (subepidermal fibrin and ulcerations).

Novel findings of Langerhans cells and interleukin-17 expression in relation to the acrosyringium and pustule in palmoplantar pustulosis.

BACKGROUND: Palmoplantar pustulosis (PPP) is a chronic and intensely inflammatory skin disease with pustules, erythema and scaling localized to the palms and soles. To date, no specific treatment is known. Earlier findings indicate the acrosyringium as the target for the inflammation. OBJECTIVES: To identify specific features of the PPP inflammatory cell infiltrate and mediators of inflammation, which might provide insight into the pathogenesis and possible future treatment of the disease. METHODS: Skin biopsies were taken from 23 patients with typical PPP (23 from involved skin and seven from noninvolved skin) and from 18 healthy controls (10 nonsmokers, eight smokers). Cell infiltrates and inflammation mediators were studied with immunohistochemistry. RESULTS: A strong inflammation was observed in lesional skin of PPP. Our main findings of Langerhans cells and interleukin-17 close to or in the acrosyringium differs from findings in psoriasis vulgaris. Other inflammatory cells such as CD4+, CD8+, regulatory T cells and CD11a+ cells were also accumulated close to the sweat duct in epidermis and papillary dermis. More CD4+, CD8+, Langerhans cells, plasmacytoid dendritic cells and a higher proportion of regulatory T cells/CD3+ cells were seen in noninvolved palmar skin from patients with PPP compared with healthy controls. CONCLUSIONS: Our novel findings indicate that the inflammation in PPP is initiated by the 'stand-by' innate immune system at the acrosyringium.

Palm tissue displaying a polyclonal autoimmune response in patients affected by a new variant of endemic pemphigus foliaceus in Colombia, South America.

We previously described a new variant of endemic pemphigus foliaceus in El Bagre, Colombia, South America (El Bagre-EPF). On physical examination, the palms and soles of El Bagre-EPF patients reveal an edematous texture and mild hyperkeratosis, in comparison with the non-glabrous skin of the patients where blisters, pustules or other lesions are commonly found. Based on the preceding observation, we tested the palms of 20 El Bagre-EPF cases and 20 controls from the endemic area for any pathological alterations in the samples by direct immunofluorescence (DIF). Our DIF demonstrated pathological deposits of fibrinogen and albumin, as well as IgG, IgA, IgM, IgD and C3c, at 1) the epidermal basement membrane zone; 2) around isolated areas in the epidermis, 3) within the dermal vessels and nerves, and 4) in areas surrounding dermal neurovascular structures and sweat glands. Specific markers for blood vessels, including 1) anti-intercellular adhesion molecule 1 (ICAM-1)/CD54, and 2) anti-junctional adhesion molecule (JAM-A); as well as specific markers for nerves, including 1) anti-glial fibrillary acidic protein (GFAP), and 2) anti-human neuron specific enolase (NSE) co-localized with the patients' autoantibodies. Although no blisters, ulcerations, pustules or erosions are clinically observed on the palms of El Bagre-EPF patients, our DIF detected distinct immunoreactivity in palm tissue. These alterations may contribute to the clinically edematous texture of the palms and the mild clinical hyperkeratosis found in most of these patients. We propose that normal glabrous skin and non-glabrous skin may be different with regard to the expression of selected molecules, which may vary in number, size or structural organization depending on their anatomical site. Our findings may also partially explain the hyperkeratotic palms that have been clinically well documented in the chronic phase of fogo selvagem i.e., endemic pemphigus foliaceus, in Brazil.

Comparative study of skin sebum and elasticity level in patients with sulfur mustard-induced dermatitis and healthy controls.

BACKGROUND: Sulfur mustard (SM) - a chemical agent - has both acute and chronic effects on skin. Xerosis, which is deemed to be due to the damage of hydrolipidic barrier of the skin, is the most common complaint of veterans exposed to the chemical. This study was designed to evaluate skin sebum and elasticity in veterans with a history of SM contact. METHODS: Three hundred and ten subjects were enrolled in this study and were divided into four groups: SM-exposed patients with current skin lesions (n=87); SM-exposed patients without skin lesions (n=71); patients with dermatitis (n=78); and normal controls (n=74). The skin sebum and elasticity were measured in four areas (forehead, suprasternal, palm and back of the hands) using a Sebumeter and a Reviscometer. RESULTS: Skin sebum was higher in participants who presented with dermatitis and had history of contact with SM than others; the difference was only statistically significant on the forehead. There was no significant difference in the skin elasticity between the four groups. CONCLUSION: While SM may increase skin sebum in long term, there is no evidence that it has a substantial effect on skin elasticity.

Aberrant aquaporin 5 expression in the sweat gland in aquagenic wrinkling of the palms.

Aquagenic wrinkling of the palms (AWP) is an uncommon disease characterized by the rapid and transient formation of edematous whitish plaques on the palms on exposure to water. Although this disease is occasionally accompanied by hyperhidrosis, the pathophysiology of AWP remains unknown. Herein we describe a patient with AWP. The location of wrinkling was limited to the areas positive for iodine-starch test after water exposure, which suggests that AWP is etiologically related to hyperhidrosis. Histologic examination revealed hyperplastic and papillated eccrine glandular epithelium with the enlarged diameter of eccrine coils. Immunohistochemically, while aquaporin 5 (AQP5), one of the water channel AQP families, was present exclusively in the dark cells of sweat glands of healthy donors, an aberrant AQP5 staining, extending to the clear cells, was found in the patient with AWP. The hyperplastic glandular epithelium and aberrant AQP5 staining in the patient's sweat glands suggest that AWP stems from dysregulation of sweating.

Abnormal keratin expression in circumscribed palmar hypokeratosis.

BACKGROUND: Circumscribed palmar or plantar hypokeratosis (CPH) is a rare skin disorder only recently described. OBJECTIVE: To determine the diagnostic features and to provide insight into the pathogenesis of CPH, with analysis of two new Japanese cases. METHODS: Dermoscopy, immunohistochemistry, electron microscopy, polymerase chain reaction amplification for human papillomavirus (HPV) DNA and 16S microbial rRNA gene profiling were conducted. RESULTS: Dermoscopy showed characteristic features using both dry and jelly immersion observation; step-like desquamation and a homogeneous erythema with regularly distributed whitish spots. Immunohistochemistry revealed strong staining with anti-pankeratin antibody (AE1+AE3) and anti-keratin 16 antibody, and decreased expression of keratin 2e. EM revealed a breakage of the corneocytes within their cytoplasm, but structures for cell attachment were intact. HPV and lesion-specific bacteria were not detected. LIMITATIONS: The number of cases analyzed was two. CONCLUSION: Hyperproliferative epidermal state along with enhanced corneocyte fragility may account for the unique features in CPH.

Role of linoleic acid in arsenical palmar keratosis.

BACKGROUND: Chronic arsenic exposure can lead to palmoplantar keratosis. In the stratum corneum of skin, linoleic acid is of the utmost importance to the inflammation, keratinization, and regeneration processes. OBJECTIVES: The aims of this study were: (i) to present quantitative information on the linoleic acid fraction of intercorneocyte lipids, and (ii) to elucidate the role of linoleic acid in the pathophysiology of arsenical keratosis. METHODS: Lipid extracts were collected from keratotic lesions in seven patients, seven arsenic-exposed subjects, and seven non-exposed control subjects. Linoleic acid levels of the specimens were estimated by reverse-phase high-performance liquid chromatography (RP-HPLC). RESULTS: There was a significant (P < 0.001) increase in mean ± standard error (SE) linoleic acid levels in arsenical keratosis patients (palm: 25.66 ± 4.95 µg/cm(2); dorsum: 28.25 ± 6.20 µg/cm(2)) compared with arsenic-exposed (palm: 2.75 ± 0.85 µg/cm(2); dorsum: 1.96 ± 0.64 µg/cm(2)) and non-exposed (palm: 1.52 ± 0.61 µg/cm(2); dorsum: 1.28 ± 0.39 µg/cm(2)) control subjects. There was no significant difference (P = 0.556) in linoleic acid concentration in the non-affected skin of the dorsum of the hand (28.25 ± 6.20 µg/cm(2)) compared with that in the palmar sites (25.66 ± 4.95 µg/cm(2)) in the patient group. The change in linoleic acid levels in the arsenic-exposed control group did not differ from that in non-exposed controls (P = 1.000). CONCLUSIONS: Linoleic acid concentration is elevated in arsenical keratosis; this finding warrants further investigation to ascertain whether linoleic acid plays a direct role in the pathophysiology of arsenical keratosis.

Investigation into different skin conditions in certain occupations.

The aim of this study was to establish whether those working in certain occupations had skin with a Lower moisture content than would be considered normaL. Skin moisture levels were measured as well as visual assessment. Results indicated that all occupational groups studied had skin that was less well hydrated than would be considered normal, although there were significant inter-individual variations within any one group. These variations were at least as significant as occupation. Awareness of the need to use gloves as protection against chemicals and to use emollients to restore condition was low, as was compliance.

Demonstration of in vitro synthesis of human papilloma viral proteins from hand and foot warts.

HPV particles purified from [35S]-methionine labeled and unlabeled halves of single hand and foot warts have been fractionated into empty, light full, and heavy full particles by buoyant density gradient centrifugation, and their proteins analyzed by two-dimensional gel electrophoresis (IEF and NEPHGE) and visualized by either fluorography or silver staining. The L1 coat protein (54 Kd) was found in trace amounts in unmodified and slightly modified forms in the labeled empty and light full particles but could not be detected in the labeled heavy particles. L1 appeared to exist in the three unlabeled particle types in differentially modified forms. A putative L2 protein was also found to be modified (74-80 Kd) and was found preferentially in the unlabeled heavy full particles. The commercial cross-reactive BPV antibody recognized a labeled 58-Kd protein found predominantly in the empty and light full particles and a pair of proteins (41-42 Kd) found unlabeled in the heavy full particles. Besides L1, there were several other proteins (IEF 40 Kd; NEPHGE 42, 38, and 36 Kd) which were detected labeled in the empty particles and in increasing unlabeled amounts in the light full and heavy full particles. Four proteins (IEF 66, 13 and 11 Kd, and NEPHGE 9 Kd) were found exclusively in the full particles and may be involved in packing the viral genome. These observations suggest that a virus particle assembly pathway exists from the empty particles, via the light full, to the mature heavy full particles.

Glucose tolerance in pustulosis palmaris et plantaris.

Glucose tolerance was investigated in 41 patients with pustulosis palmaris et plantaris. Twenty-eight (68%) of the patients showed abnormal results. These findings suggest that pustulosis palmaris et plantaris is associated with impaired carbohydrate metabolism.

Antifungal pulse therapy for onychomycosis. A pharmacokinetic and pharmacodynamic investigation of monthly cycles of 1-week pulse therapy with itraconazole.

BACKGROUND AND DESIGN: In the treatment of onychomycosis, oral therapies have generally been given as a continuous-dosing regimen. For example, the suggested dose of itraconazole for the treatment of onychomycosis has thus far been 200 mg/d for 3 months. Based on the advances in our understanding of the pharmacokinetics of itraconazole, we investigated the efficacy and nail kinetics of intermittent pulse-dosing therapy with oral itraconazole in patients who were suffering from onychomycosis. Fifty patients with confirmed onychomycosis of the toenails, predominantly Trichophyton rubrum, were recruited and randomly assigned to three (n = 25) or four (n = 25) pulses of 1-week itraconazole therapy (200 mg twice daily for each month). Clinical and mycological evaluation of the infected toenails, and determination of the drug levels in the distal nail ends of the fingernails and toenails, were performed at the end of each month up to month 6 and then every 2 months up to 1 year. RESULTS: In the three-pulse treatment group, the mean concentration of itraconazole in the distal ends of the toenails ranged from 67 (month 1) to 471 (month 6) ng/g, and in the distal ends of the fingernails, it ranged from 103 (month 1) to 424 (month 6) ng/g. At month 11, the drug was still present in the distal ends of the toenails at an average concentration of 186 ng/g. The highest individual concentrations of 1064 and 1166 ng/g were reached at month 6 for toenails and fingernails, respectively. At end-point follow-up, toenails in 84% of the patients were clinically cured with a negative potassium hydroxide preparation and culture in 72% and 80% of the patients, respectively. In the four-pulse treatment group, the mean concentration of itraconazole in the distal ends of the toenails ranged from 32 (month 1) to 623 (month 8) ng/g, and in the distal ends of the fingernails, it ranged from 42 (month 1) to 380 (month 6) ng/g. The highest individual concentrations of 1549 and 946 ng/g were reached at month 7 for toenails and at month 9 for fingernails, respectively. At month 12, the drug was still present in the distal ends of the toenails at an average concentration of 196 ng/g. At end-point follow-up, toenails in 76% of the patients were clinically cured with a negative potassium hydroxide preparation and culture in 72% and 80% of the patients, respectively. There were no significant intergroup differences between the three- and four-pulse treatment groups for the primary efficacy parameters. The drug was well tolerated with no significant side effects in either patient group. CONCLUSIONS: Following pulse therapy with itraconazole (400 mg/d given for 1 week each month for 3 to 4 months), the drug has been detected in the distal ends of nails after the first pulse, and it has reached therapeutic concentrations with further therapy. After stopping the last pulse, the drug remains in the nail plate at levels above 300 ng/g for several months. Clinical cure rates between 76% and 84% and negative mycological examination findings between 72% and 80%, respectively, were observed in toenail onychomycosis. The data suggest that pulse therapy with itraconazole is an effective and safe treatment option for onychomycosis.