Basis for enhanced barrier function of pigmented skin

Humans with darkly-pigmented skin display superior permeability barrier function in comparison to humans with lightly-pigmented skin. The reduced pH of the stratum corneum (SC) of darkly-pigmented skin could account for enhanced function, because acidifying lightly-pigmented human SC resets barrier function to darkly-pigmented levels. In SKH1 (non-pigmented) vs. SKH2/J (pigmented) hairless mice, we evaluated how a pigment-dependent reduction in pH could influence epidermal barrier function. Permeability barrier homeostasis is enhanced in SKH2/J vs. SKH1 mice, correlating with a reduced pH in the lower SC that co-localizes with the extrusion of melanin granules. Darkly-pigmented human epidermis also shows substantial melanin extrusion in the outer epidermis. Both acute barrier disruption and topical basic pH challenges accelerate re-acidification of SKH2/J (but not SKH1) SC, while inducing melanin extrusion. SKH2/J mice also display enhanced expression of the SC acidifying enzyme, secretory phospholipase A2f (sPLA2f). Enhanced barrier function of SKH2/J mice could be attributed to enhanced activity of two acidic pH-dependent, ceramide-generating enzymes, β-glucocerebrosidase and acidic sphingomyelinase, leading to accelerated maturation of SC lamellar bilayers. Finally, organotypic cultures of darkly-pigmented-bearing human keratinocytes display enhanced barrier function in comparison to lightly-pigmented cultures. Together, these results suggest that the superior barrier function of pigmented epidermis can be largely attributed to the pH-lowering impact of melanin persistence/extrusion and enhanced sPLA2f expression

Wound infection by Pantoea agglomerans after penetrating plant injury

Data de publicació electrònica: 24-02-2021Pantoea agglomerans is a ubiquitous gram-negative bacterium that has been linked to skin and joint infections secondary to plant injuries. Herein we report a 58-year-old woman who presented with 2 erythematous nodules with purulent discharge on the anterior aspect of the right leg that developed after a penetrating plant injury. The patient was initially treated with amoxicillin-clavulanic acid, cloxacillin and clindamycin without improvement. P. agglomerans was isolated from both exudate and skin biopsy cultures. Healing of the lesions was achieved after the spontaneous release of a retained plant fragment and treatment with cotrimoxazole. Identification of P. agglomerans in persistent exudative lesions should alert the clinician regarding a possible previous plant injury and retained vegetal fragments. Conventional antibiotic treatment and the extraction of retained foreign bodies usually lead to complete resolution

Diagnostic usefulness of immunohistochemical evaluation of CD1a antigen and polyclonal antiLeishmania antibodies in cutaneous Leishmaniasis

Background. Different immunohistochemical markers to detect amastigotes in cutaneous Leishmaniasis have been proposed with variable diagnostic usefulness. Objectives. To evaluate the diagnostic usefulness of immunohistochemical amastigotes identification by specific polyclonal anti-Leishmania antibodies and CD1a expression (clone EP3622) in a series of PCR confirmed cutaneous Leishmaniasis. Materials and methods. Thirty-three skin samples corresponding to PCR confirmed cutaneous Leishmaniasis were included in the study. All samples were stained with Hematoxylin-eosin and Giemsa. Moreover, immunohistochemical studies with anti-CD1a and anti-Leishmania antibodies were performed. The patients clinical features and the observed histopathological features were also recorded. Results. From the selected 33 biopsies, Leishmania spp. amastigotes were detected in 48.4% of cases with conventional Hematoxylin-eosin stain and in 57.5% of cases by Giemsa staining. In 31/33 cases, anti-CD1a allowed us to identify parasitic structures, and in 33/33 cases amastigotes were detected with anti-Leishmania antibodies. Concordance between both techniques, antiCD1a and anti-Leishmania, was 94% [CI 95%: (79,8%- 99,3%)]; p value <0.05. The sensitivity of anti-CD1a in comparison with the PCR was 94%, with a positive predictive value of 100%. Two cases of low parasitic index were negative for CD1a immunostaining. In cases with high parasitic index, anti-CD1a stained amastigotes in superficial and deep dermis. Only a few cases were originally diagnosed with the available histological techniques, needing PCR for Leishmania spp. identification. Conclusions. Anti-CD1a antibody seems to be a useful technique to identify amastigotes when PCR and anti-Leishmania antibodies are not available. The sensitivity to detect amastigotes is increased when the CD1a immunostaining is added to the classical Haematoxylin – eosin and Giemsa staining

Persistent cutaneous abdominal ulcerations secondary to diffuse dermal angiomatosis: an underestimated sign for severe atherosclerosis: A case report.

BACKGROUND: Diffuse dermal angiomatosis (DDA) is a rare, acquired, reactive vascular proliferation, clinically characterized by livedoid erythematous-violaceous plaques, which frequently evolve to ulceration and necrosis. Histopathologically, it is manifested by a diffuse proliferation of endothelial cells within the full thickness of the dermis. DDA has been mainly associated with severe peripheral atherosclerosis. METHODS: We report a 63-year-old woman who presented with multiple erythematous-violaceous plaques with central deep skin ulcers on thighs, lower abdomen, and perianal area, associated with intermittent claudication, low-grade fever, and weight loss. Initially, the clinical picture along with positive cultures for Klebsiella pneumoniae suggested a multifocal ecthyma gangrenosum; nevertheless, a skin biopsy showed a diffuse dermal proliferation of endothelial cells interstitially arranged between collagen bundles. A computed tomography scan revealed severe aortic atheromatosis with complete luminal occlusion of the infrarenal aorta and common iliac arteries. RESULTS: The diagnosis of DDA secondary to severe atherosclerosis was established. The patient underwent a left axillofemoral bypass surgery with a rapidly healing of the ulcers in the next weeks./nCONCLUSIONS: DDA should be considered in the differential diagnosis of livedoid ischemic lesions. Recognition of DDA as a cutaneous sign of severe peripheral vascular disease is important for both dermatologists and internists. Recognition of risk factors and their management with an early intervention to correct tissue ischemia can be curative

Expression of epidermal CAMP changes in parallel with permeability barrier status

Two critical defensive functions of the outer epidermis, the permeability barrier and antimicrobial defense, share certain structural and biochemical features. Moreover, three antimicrobial peptides (AMPs), i.e., mouse β-defensin 3 (mBD3), mouse cathelicidin antimicrobial peptide (mCAMP), and the neuroendocrine peptide, catestatin (Cst), all localize to the outer epidermis, and both mBD3 and mCAMP are secreted from the epidermal lamellar bodies with other organelle contents that subserve the permeability barrier. These three AMPs are upregulated in response to acute permeability barrier disruption, whereas conversely, mCAMP−/− mice (unable to combat Gram-positive pathogens) also display abnormal barrier homeostasis. To determine further whether these two functions are co-regulated, we investigated changes in immunostaining for these three AMPs in skin samples in which the permeability barrier function in mice had been either compromised or enhanced. Compromised or enhanced barrier function correlated with reduced or enhanced immunohistochemical expression of mCAMP, respectively, but conversely with Cst expression, likely due to the role of this AMP as an endogenous inhibitor of cathelicidin expression. mBD3 expression correlated with experimental barrier perturbations, but poorly with developmental changes in barrier function. These studies show that changes in cathelicidin and Cst expression parallel changes in permeability barrier status, with a less clear relationship with mBD3 expression.OAIID:oai:osos.snu.ac.kr:snu2011-01/102/2008000790/8SEQ:8PERF_CD:SNU2011-01EVAL_ITEM_CD:102USER_ID:2008000790ADJUST_YN:YEMP_ID:A079501DEPT_CD:801CITE_RATE:6.314FILENAME:camp and barrier status jid.pdfDEPT_NM:의학과SCOPUS_YN:YCONFIRM:

Epidemiological characteristics and factors associated with repeat sexually transmitted infections in Barcelona, Spain over a decade

In the last few years, the frequency of sexually transmitted infections (STI) has increased, as has the number of people with multiple infections. The aim of our study was to describe the epidemiological characteristics of persons with repeated bacterial STI and to determine the risk factors for these episodes in persons living in Barcelona during the period 2007-2018. We studied all cases of bacterial STI included in the STI registry of Barcelona. Repeated STI were defined as a diagnosis of gonorrhea, syphilis, or lymphogranuloma venereum (LGV) after a first episode of one of these infections. Analysis was stratified by sex and place of birth. The factors associated with time to reinfection were determined by Kaplan-Meier estimates, while the factors associated with risk of infection were determined by a Cox proportional hazards model. Of 9927 persons with a diagnosis of bacterial STI, 1690 (17.0%) had at least two episodes of STI during the study period. On multivariate analysis, repeat STI were independently associated with male sex assigned at birth (HR: 3.45; 95%CI 2.22-5.36), age less than 34 years (HR: 1.22; 95%CI 1.10-1.35); gay, bisexual, and other men who have sex with men, and transgender o transsexual woman (GBSMS/Trans) (HR: 4.03; 95%CI 3.24-5.03), having gonorrhea as first diagnosis (HR:1.49, 95%CI 1.34-1.66) or LGV (HR:1.75; 95%CI 1.47-2.08) and coinfection with HIV (HR:1.98; 95%CI 1.78-2.21). Sexual health programs should be strengthened to prevent STI and reinfection in key populations

Paradoxical benefits of psychological stress in inflammatory dermatoses models are glucocorticoid mediated.

Acute psychological stress (PS) mobilizes metabolic responses that are of immediate benefit to the host, but the current medical paradigm holds that PS exacerbates systemic and cutaneous inflammatory disorders. Although the adverse consequences of PS are usually attributed to neuroimmune mechanisms, PS also stimulates an increase in endogenous glucocorticoids (GCs) that compromises permeability barrier homeostasis, stratum corneum cohesion, wound healing, and epidermal innate immunity in normal skin. Yet, if such PS-induced increases in GC were uniformly harmful, natural selection should have eliminated this component of the stress response. Hence, we hypothesized here instead that stress-induced elevations in endogenous GC could benefit, rather than aggravate, cutaneous function and reduce inflammation in three immunologically diverse mouse models of inflammatory diseases. Indeed, superimposed exogenous (motion-restricted) stress reduced, rather than aggravated inflammation and improved epidermal function in all three models, even normalizing serum IgE levels in the atopic dermatitis model. Elevations in endogenous GC accounted for these apparent benefits, because coadministration of mifepristone prevented stress-induced disease amelioration. Thus, exogenous stress can benefit rather than aggravate cutaneous inflammatory dermatoses through the anti-inflammatory activity of increased endogenous GC