Chemometric approach for investigating the skin surface lipids (SSLs) composition: influence of geographical localization

Skin surface lipids (SSLs), arising from both sebaceous glands and skin removal, form a complex lipid mixture composed of free fatty acids and neutral lipids. They are present in the hydrolipidic film and have a close relationship with the stratum corneum lipids. Thus, SSLs participate in the barrier function. One can expect a physiological adaptation of the SSLs composition according to geographical localization or skin pigmentation. In this study, SSLs obtained from three groups of volunteers (light and dark skin, living in France and dark skin, living in Ivory Coast) have been investigated. High-temperature gas chromatography/mass spectrometry has been used to study SSLs composition. The variability in the SSLs chromatographic profiles has been investigated, using chemometric methods which allowed us to highlight the sapienic acid (C16: 1Δ6) as discriminant according to geographical localization. This result is of a great interest regarding sapienic acid properties. However, no significant variation has been detected following skin pigmentation. In parallel, SSLs Raman spectra were collected in order to determine the organization and the conformational order of lipids. The spectral data treatment revealed discriminant variation in the υ C-C stretching region revealing changes in the conformational order of the SSLs following geographical localization.     

Tips and tricks in the dermoscopy of pigment lesions

ABSTRACT: Dermoscopy is a useful, widely used tool for examining pigmented lesions, especially helpful in cases of an uncertain nature. Nevertheless, doctors may experience diagnostic difficulties while using this method. An example of this may be found in the examination of subcorneal hematoma, dark nevi with black lamella or lesions of acral volar skin. In such cases, a few diagnostic tricks have proven to be helpful in achieving diagnostic accuracy. This paper reviews various methods of performing dermoscopy, suggesting a number of simple, yet helpful tests. These include the adhesive tape test, the skin scraping test and the ink furrow test. The adhesive tape test is helpful in differentiating between dark melanocytic nevi and melanoma. Hematoma may be more easily differentiated with the use of the socalled skin scraping test. The confirmation of benign and melanocytic lesions of acral volar skin, on the other hand, is more accurate when using the ink furrow test. These methods have been discussed here based upon a series of literary reviews, the authors own experience and, also, iconography. The present article describes novel methods used in dermoscopy, helping to bring about a faster, more accurate diagnostics of those lesions which have proven to be more difficult to recognize. Helpful tricks, such as have been known to professional literature, as well as the authors own experience (for instance, applying urea cream to hyperkeratotic lesions or using photographs of skin lesions taken with the aid of a mobile phone camera - all prior to surgery) will surely be considered beneficial to the practitioner, be it dermatologist or any other physician.     

Contrast enhanced phototrichogram (CE-PTG): an improved non-invasive technique for measurement of scalp hair dynamics in androgenetic alopecia--validation study with histology after transverse sectioning of scalp biopsies

Global changes of scalp hair represent the cumulative end result of discrete changes of individual hair follicle structure and/or function. Monitoring of such changes requires an accurate non-invasive method. The phototrichogram (PTG) appears to be an appropriate choice to do so. However, a known weakness of the method is the lack of detection of less pigmented or thinning hair. Balding scalp of male subjects with androgenetic alopecia (AGA) was analysed with our previously published PTG method and with contrast enhanced (CE-)PTG followed by biopsy and transverse section examination with the light microscope. As compared with PTG, the CE-PTG method significantly improved detection not only of thin but also of thick hair. Equal numbers of thick (diameter > 40 mm) hair were detected with CE-PTG and with histology. CE-PTG was also able to detect the severely miniaturised hair fiber (down to 8 mm diameter) and was comparable to scalp biopsy analysis. The latter could identify hair fibres, which did not reach the scalp surface, a measure that is considered as not clinically significant. All growth stages - anagen, catagen and telogen - as well as the empty follicle stage could clearly be observed with CE-PTG. Staging of the more severely affected hair follicles was not always possible neither with CE-PTG nor histology - even with serial sectioning. The finding of such technological advantages makes the CE-PTG a first choice method for detailed analysis of hair cycling in androgenetic alopecia - a scalp disorder characterised by extreme hair follicle miniaturisation, decreased hair pigmentation and hair thinning.     

Comparative analysis of colorimetric staining in skin using open‐source software

Colorimetric staining techniques such as immunohistochemistry (IHC), immunofluorescence (IF) and histochemistry (HC) provide useful information regarding the localization and relative amount of a molecule/substance in skin. We have developed a novel, straightforward method to assess colorimetric staining by combining features from two open‐source software programs. As a proof of principle, we demonstrate the utility of this approach by analysing changes in skin melanin deposition during the radiation‐induced tanning response of Yucatan mini‐pigs. This method includes a visualization step to validate the accuracy of colour selection before quantitation to ensure accuracy. The data show that this method is robust and will provide a means to obtain accurate comparative analyses of staining in IHC/IF/HC samples.     

Optoacoustic imaging and potential applications of raster-scan optoacoustic mesoscopy in dermatology

Optoacoustic imaging (OAI) is a hybrid imaging modality that integrates the benefits of optical contrast and ultrasound detection. Raster-scan optoacoustic mesoscopy (RSOM) is an emerging OAI method that provides information about several dermatological conditions’ structural, functional, and molecular features. We searched PubMed and Google Scholar databases through September 2021 for contributions relevant to OAI in the English language. This review contains 32 studies and other relevant literature. Several studies indicate that RSOM is helpful in inflammatory skin conditions such as psoriasis and eczema, especially as it allows more accurate quantification of inflammation-related alterations such as changes to the dermal vasculature. In psoriasis, RSOM can provide objective early diagnosis and monitoring of disease activity and treatment efficacy. Multispectral RSOM, a method in which skin is lightened at more than a single wavelength, is beneficial in diagnosing and monitoring hypoxia-associated conditions, such as systemic sclerosis and chronic wounds. OAI techniques can visualize the pathologicvascularization of skin cancers and quantify their oxygenation status which helps differentiate them from normal skin. Also, they can measure the depth of malignant melanoma and detect the metastatic spread of melanoma cells to sentinel lymph nodes. As demonstrated in this contribution, there is a large spectrum of potential applications of OAI imaging, especially RSOM, in diagnosing, treating, and managing skin diseases.     

Wound measurement by computer-aided design (CAD): a practical approach for software utility

The measurement of the size of a wound is important in order to monitor its progress. An ideal method should be accurate, reproducible, sensitive, flexible, standardized, and informative. ¹ Various methods for wound measurement have been described. ^{2 - 4} A direct method for the measurement of ulcers using a computer has been proposed. ⁵ We use computer-aided design (CAD) software to overcome some of the shortcomings, such as assessability, utility, cost, and sterilization, of the direct method ⁵ debated in Wysocki. ¹      

Strategies for assessing the degree of photodamage to skin: a systematic review of the literature

As our understanding of the role of ultraviolet (UV) radiation exposure in causing skin cancer continues to be enhanced, it is important that clinicians and researchers are familiar with the various methods for assessing photodamage to skin. This paper provides a systematic review of the published literature on invasive and noninvasive methods used to quantify lifetime UV exposure ('photoageing'). Clinical examination, histopathology, immunohistochemistry, skin surface topography and ultrasound, in addition to newer technologies such as reflectance confocal microscopy, optical coherence tomography and multiphoton tomography, are reviewed. It is concluded that histopathological solar elastosis alone should not be viewed as a 'gold standard' diagnostic test and that there is no single method available to give accurate quantification of the degenerative changes associated with photodamage. Although additional research into sensitivity and specificity is still needed, skin surface topography currently has the most support in the literature as a valid and reliable noninvasive tool for the assessment of photoageing.     

Method of assessing involved facial areas: rule of fours

BACKGROUND: Disease extent or affected area is probably the most easily and most frequently measured index of patient disability in dermatological disorders such as psoriasis. However, no standard method is available for assessing involved facial areas. OBJECTIVES: To devise a method for assessing involved facial areas and to examine its validity and reliability. METHODS: In study 1, the facial areas of 26 healthy adults were analysed and a new method for assessing facial areas was devised. In study 2, the validity and reliability of the devised method were investigated by 10 dermatologists using 30 photographs of patients with facial psoriasis. RESULTS: In study 1, facial regions were defined to have percentage areas that were multiples of 4% of the total facial area (which we refer to as the rule of fours), i.e. forehead 24%, one cheek 20%, perioral area 8%, one aspect of an ear 4%, one periorbital area 4%, and nose 4%. In study 2, a comparison of values obtained using the rule of fours with those obtained using an image analysis system showed excellent intrarater and inter-rater reliability when using the rule of fours. CONCLUSIONS: The rule of fours is useful for assessing involved facial areas. The application of this rule was found to provide an accurate and reliable method as compared with image analysis.     

Gegenwärtiger Stand der operativen und endovaskulären Varizenchirurgie

The classical varicose vein operation represents the "gold standard" in the operative approach to this condition. The results of the standard procedure are very good especially with regard to complications. The recurrence rate is estimated between 6% and 60%, but the true rate is unknown, since there is no generally accepted definition of recurrent varicosities. Endovascular procedures for the elimination of the superficial venous system - radiofrequency obliteration and laser therapy - have established themselves as alternative, minimal invasive procedures. Good results up to 2 years post operatively have been documented; for radiofrequency obliteration, very good results 5 years after surgery are available. Less well-known procedures are available, such as the CHIVA method, which represents a totally different pathophysiological concept. Data on the efficacy of this method are limited, making an evaluation difficult. The spectrum of operative treatment methods of the superficial venous system and its side branches has increased tremendously because of new technical developments. The surgeon must inform the patient about the pros and cons of each procedure and the anticipated results, as well as making an accurate decision as to which methods are best suited for the patient.     

Comparison of Nested PCR and RFLP for Identification and Classification of Malassezia Yeasts from Healthy Human Skin

Background

Malassezia yeasts are normal flora of the skin found in 75~98% of healthy subjects. The accurate identification of the Malassezia species is important for determining the pathogenesis of the Malassezia yeasts with regard to various skin diseases such as Malassezia folliculitis, seborrheic dermatitis, and atopic dermatitis.

Objective

This research was conducted to determine a more accurate and rapid molecular test for the identification and classification of Malassezia yeasts.

Methods

We compared the accuracy and efficacy of restriction fragment length polymorphism (RFLP) and the nested polymerase chain reaction (PCR) for the identification of Malassezia yeasts.

Results

Although both methods demonstrated rapid and reliable results with regard to identification, the nested PCR method was faster. However, 7 different Malassezia species (1.2%) were identified by the nested PCR compared to the RFLP method.

Conclusion

Our results show that RFLP method was relatively more accurate and reliable for the detection of various Malassezia species compared to the nested PCR. But, in the aspect of simplicity and time saving, the latter method has its own advantages. In addition, the 26S rDNA, which was targeted in this study, contains highly conserved base sequences and enough sequence variation for inter-species identification of Malassezia yeasts.     

Fluorimetric and microbiological assays of erythromycin concentrations in plasma and vaginal washings.

Using a microbiological and a fluorimetric assay to determine penetration of erythromycin into vaginal fluids, concentrations were measured in plasma from nine men one hour after a single oral dose of erythromycin stearate 2 g and in vaginal washings and plasma samples taken simultaneously from 11 women two hours after the last dose of a 10-day course of erythromycin stearate (250 mg four times daily). Both assay methods gave accurate and reproducible results in plasma but only the fluorimetric method was capable of measuring concentrations of erythromycin in vaginal washings. The latter method had many advantages in estimating drug concentrations in body fluids such as vaginal washings and the results from it may provide an index of tissue penetration and of patient compliance in adhering to drug regimens.     

Cutaneous vasculitis in rheumatologic disease: Current concepts of skin and systemic manifestations

Cutaneous vasculitis may be limited to the skin, a manifestation of systemic vasculitis, or a sign of an important underlying disease state. A thorough and systematic approach is required for accurate diagnosis and evaluation of such patients to enable appropriate management of the vasculitis and any associated condition. Occasionally, cutaneous vasculitis is a manifestation or presenting sign of connective tissue disease, such as systemic lupus erythematosus, Sjögren syndrome, or another condition. Such patients are at risk for poor outcomes related to systemic manifestations of vasculitis, as well as increased severity of the underlying disease. Recognition of this important subset of patients with skin vasculitis enables appropriate workup and successful management.     

Histologic mimickers of mycosis fungoides: a review

Mycosis fungoides (MF) is a rare type of non-Hodgkin's lymphoma affecting the skin. Because MF develops slowly over several years and may have a variety of clinical presentations, including itchy patches, plaques or tumors that may be confused with common benign conditions such as eczema and psoriasis, the disease presents a diagnostic challenge. The average time to diagnosis varies but is frequently as long as 3 to 6 years. Skin biopsies frequently reveal non-specific features of several dermatoses; thus, histologic evaluation of the disease is also challenging. Importantly, various significant and/or benign conditions may mimic MF histologically and result in a misdiagnosis of MF. Here we review the reported histologic mimickers of MF and discuss both similar and differentiating features of each, in order to aid in more accurate interpretation of diagnostically challenging skin biopsies. Clinicopathologic correlation is ultimately essential to make accurate diagnosis of MF and its histologic mimickers.     

Glove imprint templating: A versatile tool in skin graft surgery and more

Measurement of the shape and size of skin lesions is an important component of skin excision and repair, especially in full‐thickness skin grafting. Current templating methods can be time‐consuming and may lead to inaccurate sizing of both full‐thickness and split‐thickness skin grafts. A novel, accurate, and time‐efficient method has been employed for 10 years in a dermatology clinic, in addition demonstrating utility in additional applications. A surgical glove is used to gain an imprint of a marked surgical incision site, to transcribe to the donor site for graft harvest. Further, the size of lesions in difficult‐to‐see areas of the body can be shown to patients. This method has been found to be clinically useful in reducing procedure times and providing accurate graft templates, as well as improving patients' satisfaction by helping them to understand the procedure. This method is also advantageous in obtaining informed consent by helping to clearly demonstrate the size of simple elliptical excisions.     

UV/VIS absorbance allows rapid,accurate, and reproducible mass determination of corneocytes removed by tape stripping

The accurate determination of the mass of the horny layer removed by tape stripping is a decisive prerequisite for the application of this technique in penetration studies. A novel method using optical spectroscopy to determine the amount of stratum corneum (SC) is presented. We could show that the absorbance measured in the visible spectral range accurately reflects the mass of the SC fixed on individual tapes. Furthermore, absorbance measurement allows determination of the absolute mass of corneocyte aggregates on the removed tape strips. Topically applied substances do not disturb the spectroscopic measurements in contrast to the conventionally employed weight determination. Identical results were obtained when performing spectroscopic horny layer quantification independently in two separate institutions. Taken together, this new method is rapid, sensitive, reproducible, and accurate. We anticipate a wide application in penetration studies as well as in dermatopharmacokinetics.     

A practical method for the estimation of vitiligo surface area: a comparison between the point counting and digital planimetry techniques

The accurate measurement of vitiligo surface area is fundamental to the evaluation of treatment efficacy. Digital photography, planimetry and clinical evaluation by the clinician have been used for assessment. Although digital photography with computerized planimetry is a reliable and accurate method, it is labour intensive and expensive. The aim of this study was to evaluate the accuracy and reliability of the point counting method and to compare it with digital planimetry techniques for the estimation of vitiligo surface area. Surface areas of 31 vitiligo lesions of five volunteers were estimated using the point counting and digital planimetry methods. Three independent observers evaluated the outlined areas twice using the point counting technique with an interval of 2 weeks. The same lesions were also measured by one observer applying digital planimetry. The estimation results of three observers were compared using inter and intra-observer correlation analysis test. There was significant inter- and intra-observer agreement for all measurements. There was also significant coincidence between each observer's estimation of the point counting and digital planimetry method. No significant differences on the results of surface area obtained using the two methods were found (p > 0.05). The point counting method may be used as a direct and reliable technique to measure the vitiligo surface area.     

CADASIL-an unusual manifestation with prominent cutaneous involvement

Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leucencephalopathy (CADASIL) is a rare vascular disorder affecting mainly the central nervous system with transient ischaemic attacks, strokes, psychiatric symptoms and dementia. It is a progressive familial disease owing to mutations in the Notch3 gene. Clinically apparent skin involvement is usually absent. Electron microscopy of seemingly uninvolved skin reveals characteristic granular deposits in the basal lamina of vessels and adnexals. We report on a case of CADASIL with generalized haemorrhagic macules and patches. Typical neurological symptoms as well as classical findings in histopathology and electron microscopy confirmed the diagnosis. Immunofluorescence showed an increased number of vessels with walls markedly thickened by deposits of fibrin, complement and immunoglobulins. This method could serve as an additional method for accurate diagnosis of CADASIL.     

Schwannoma Presenting as a Scalp Mass: A Case Report with Magnetic Resonance Imaging Findings

A schwannoma can develop anywhere along the course of nerves. However, a schwannoma presenting as a scalp nodule is rare. Here, we present a rare case of schwannoma on the scalp with a review of magnetic resonance imaging (MRI) findings, which was initially misdiagnosed as an epidermal cyst or vascular malformation despite various radiologic examinations. Recognition of characteristic MRI features of schwannomas, such as low signal margin, target, entering-and-exiting-nerve, and fascicular signs, may result in an accurate diagnosis and proper management of tumors. In this report, we summarized differential characteristics of a schwannoma with an epidermal cyst and a lipoma.     

Phakomatous Choristoma in a 10‐Week‐Old Boy: A Case Report and Review of the Literature

Phakomatous choristoma (PC) is a rare benign congenital lesion of lenticular anlage. It presents in young patients as a firm subcutaneous mass in the medial eyelid or orbit and may raise clinical concern for neoplasms such as rhabdomyosarcoma, but its histopathology is distinct, consisting of dense collagenous stroma and eosinophilic cuboidal epithelial cells forming nests, tubules, cords, or pseudoglands. We present a case of PC in a 10‐week‐old boy to illustrate the unique clinical, histopathologic, and immunophenotypic features of this condition and to reaffirm that familiarity with this rare entity aids accurate diagnosis.