Clinical and microbiological properties of Staphylococcus lugdunensis skin infections

Staphylococcus lugdunensis is an emerging pathogen in skin and soft tissue infections that was previously considered a commensal. The aim of this study was to elucidate the characteristics of skin infections by S. lugdunensis and its appropriate management, in a tertiary referral medical center. The clinical files, bacterial cultures and histopathology reports of all S. lugdunensis isolates from skin infections over a period of 8 years (September 2009–September 2017) were reviewed. S. lugdunensis was isolated from 29 patients with skin infections, aged 7–89 years (mean 33.3 years). A state of immune suppression (drug‐induced, malignancy or diabetes) was present in five patients (17%). Folliculitis and cutaneous pustulosis were the most common presentations (16 cases, 55%), followed by secondary infection of hidradenitis suppurativa (five cases, 17%). Other sources of isolation were infected molluscum contagiosum (two cases), folliculitis decalvans (one case), dissecting cellulitis (one case), abscess (one case), cyst (one case), impetigo (one case) and granuloma after trauma (one case). The in vitro antibiotic sensitivity tests showed susceptibility to most tested antibiotics, although a few isolates were resistant to gentamycin, penicillin and oxacillin. In 19 of 20 patients for whom follow ups were available, cutaneous manifestations improved or resolved with proper local and/or oral antibiotic therapy. S. lugdunensis may play a role as a primary or secondary pathogen in various skin infections, most commonly folliculitis and pustulosis. Proper antibiotic therapy may lead to improvement or resolution.     

Procalcitonin as a diagnostic indicator for systemic bacterial infections in patients with Stevens–Johnson syndrome/toxic epidermal necrolysis

Elevated serum procalcitonin (PCT) level has been reported to be a diagnostic index in systemic bacterial infections, but it can also increase in some non‐infectious inflammatory diseases. Stevens–Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) is a rare immune‐mediated cutaneous mucosal reaction which is susceptible to bacterial infections and may have elevated PCT levels. The value of serum PCT has not been assessed in series of SJS/TEN patients. We aimed to investigate the PCT levels in SJS/TEN patients with systemic bacterial infections (systemic infected group), with skin surface bacterial infections (skin surface infected group) and without infections (non‐infected group), to assess whether PCT was a valuable indicator for systemic bacterial infections in SJS/TEN patients. The PCT and C‐reactive protein (CRP) levels of 42 inpatients with SJS/TEN were retrospectively analysis. The receiver–operator curve (ROC) was used to determine the diagnostic efficacy of PCT for systemic bacterial infections in SJS/TEN patients. The results demonstrated that PCT levels in the systemic infected group were significantly higher than those in the other two groups (P < 0.05). There was no significant difference in CRP between the three groups. The cut‐off PCT level of 0.65 ng/mL calculated by ROC had optimal diagnostic efficacy, with sensitivity and specificity of 84.6% and 89.7%, respectively. PCT and severity‐of‐illness score for toxic epidermal necrolysis were positively correlated (P < 0.05). In conclusion, PCT is a valuable index and superior to CRP in detecting systemic bacterial infections in SJS/TEN patients. The level of PCT can partially reflect the severity of the disease.     

Distribution of skin temperature in Mexican children

Background: Infrared thermography can be a valuable diagnostic tool in the evaluation and management of several pathologies; however, the temperature pattern of the healthy body should be known in order to perform a more precise clinical evaluation. Methods: A total of 25 healthy children (10 female and 15 male) were examined with a thermographic camera. Eighty‐four temperature points of the body were recorded, saved in a database, and analyzed. Results: The measurements showed that the forehead, neck, and the cervical area have the highest average temperatures of the whole body, and that the temperature distribution between boys and girls is very similar. The difference in skin temperature along the y‐axis of the body varied up to 5.1 °C; however, the average difference in skin temperature along the x‐axis of the body was 0.7 °C. These temperature variations observed in children are lower than the ones reported for adults, which could be due to a greater variation of body fat distribution in adults. Conclusion: This study shows that thermography could be a good tool for disease diagnosis in children as there is a lower skin temperature variation among children than among adults.     

Age‐related changes in skin mechanical properties: a quantitative evaluation of 120 female subjects

Background/purpose: The most commonly used method to determine the mechanical ability of skin is the creep test using suction chamber devices. Until now, there is no scientific consensus upon which skin deformation parameters and which body sites are particularly suitable to describe age‐related changes in human skin mechanics. The aim of this study was to find those mechanical skin parameters best representing influence of aging at five different body sites. Methods: A total of 120 healthy women aged 18–65, divided into four similar age groups, were included in this study. The biomechanical properties of the skin were measured using the Cutometer^® MPA 580 on five body sites: cheek, neck, cleavage, volar forearm and back of the hand. In order to analyze parameters referred to 1 mm skin thickness, we also used 20 MHz sonography (DUB 20). Results: A high average correlation with age was found for the parameters U_a/U_f, U_r/U_e, U_r, U_r/U_f and U_a. Only low correlation with age was found for the parameters U_v/U_e, U_f‐U_a, U_f5/U_f, U_d/U_f and U_a5. The localizations cheek, forearm and neck showed the highest correlation with age, while cleavage showed only low correlation. Conclusion: According to the results of our study, we recommend the parameter ratio of elastic recovery to distensibility (U_r/U_f) as well as the gross elasticity (U_a/U_f) for evaluation of aging effects on the mechanical properties of skin. Their high correlation with age makes them particularly applicable to represent the influence of aging onto skin mechanical properties. Most suitable localizations to evaluate skin aging are cheek, forearm and neck.     

Relationships between skin properties and environmental parameters

Background/purpose: Many authors have written about skin physiological parameters and their changes according to different environmental conditions. Nevertheless, the literature puts in evidence disagreement among different studies due to the great variability in these parameters and due to the difficulty in comparing the results obtained under different working conditions. Hence, the aim of this work is to attempt to clarify the relationship between some skin properties, such as transepidermal water loss (TEWL), skin hydration and mean skin temperature (T_sk), and the environmental parameters of ambient temperature (T_a) and relative humidity (RH), with the help of a climatic chamber to make the environment reliable. This work must be considered as the preliminary step of a wider project dealing with textile engineering: the results will be used in identifying criteria for textile design with the aim of producing more comfortable clothing. Methods: Experiments were carried out in a climatic chamber with independently controlled T_a and RH. All the combinations between three levels of T_a (20°C, 25°C and 30°C) and four levels of RH (25%, 45%, 65% and 85%) were used on a panel of six young female subjects. The assessments made were: skin surface hydration using an electrical capacitance method, TEWL using a Tewameter and T_sk using a set of thermistors. Results: The results showed a significant correlation between TEWL and T_a, while the RH had a weaker effect on TEWL in the temperature range under investigation. Also, T_sk showed a higher correlation with T_a compared with RH. Finally, skin surface hydration was found to be strongly affected by both environmental parameters. Conclusions: The analysis of experimental data resulted in the elaboration of some easy empirical models useful to evaluate the changes in TEWL, skin hydration and T_sk in different climatic conditions. These relationships must be considered to be valid only in a restricted range of T_a (20–30°C) and RH (25–85%) for young female subjects (25–35 years old).     

Use of procalcitonin,C‐reactive protein and white blood cell count to distinguish between lower limb erysipelas and deep vein thrombosis in the emergency department: A prospective observational study

Early differentiation of erysipelas from deep vein thrombosis (DVT) based solely on clinical signs and symptoms is challenging. There is a lack of data regarding the usefulness of the inflammatory biomarkers procalcitonin (PCT), C‐reactive protein (CRP) and white blood cell (WBC) count in the diagnosis of localized cutaneous infections. Herein, we investigated the diagnostic value of inflammatory markers in a prospective at‐risk patient population. This is an observational quality control study including consecutive patients presenting with a final diagnosis of either erysipelas or DVT. The association of PCT (μg/L) and CRP (mg/L) levels and WBC counts (g/L) with the primary outcome was assessed using logistic regression models with area under the receiver–operator curve. Forty‐eight patients (erysipelas, n = 31; DVT, n = 17) were included. Compared with patients with DVT, those with erysipelas had significantly higher PCT concentrations. No significant differences in CRP concentrations and WBC counts were found between the two groups. At a PCT threshold of 0.1 μg/L or more, specificity and positive predictive values (PPV) for erysipelas were 82.4% and 85.7%, respectively, and increased to 100% and 100% at a threshold of more than 0.25 μg/L. Levels of PCT also correlated with the severity of erysipelas, with a stepwise increase according to systemic inflammatory response syndrome criteria. We found a high discriminatory value of PCT for differentiation between erysipelas and DVT, in contrast to other commonly used inflammatory biomarkers. Whether the use of PCT levels for early differentiation of erysipelas from DVT reduces unnecessary antibiotic exposure needs to be assessed in an interventional trial.     

Impact of defensins-containing body cream on skin composition

Background and Aims

Defensins are peptides capable of reactivating latent LGR6 stem cells in the basal layer. When applied topically, these peptides can reduce signs of skin aging and increase dermal thickness. This study investigates the effects of a topical defensin formulation on extremity skin composition.

Methods

An open label, single arm clinical trial was conducted on participants with dry, photoaged, or dull skin. A defensin-containing hand and body cream was applied twice daily for 6 weeks to the hands, forearms, elbows, and knees. Photographs and objective measurements of skin hydration, viscoelasticity (VE), retraction time (RT), thickness, density/transepidermal water loss (TEWL), as well as self-evaluation of skin quality and characteristics were obtained pre- and post- intervention.

Results

After the study period, RT decreased by 56% across all body sites (p < 0.001) and VE improved at the elbow (125%, p = 0.009) and knee (110%, p < 0.001). Skin density also increased in all 4 body sites (40%, p < 0.001), while skin thickness increased at the elbow (29%, p = 0.03) and knee (17%, p = 0.04). Skin hydration increased at the elbow, knee, and forearm by 99%, 28%, and 16%, respectively (p < 0.05), while TEWL improved at the elbow only (−39%, p = 0.02). Patients' self-evaluations showed improvements in overall skin quality and in the domains of dryness, ashiness, wrinkling, pigmentation, redness, roughness, and discomfort (p < 0.05).

Conclusions

Following 6-week use of a defensin-containing cream, subjects reported significant improvement across many subjective skin domains. Similarly, objective measurements demonstrated significant improvement in skin architecture at select sites.     

Serum interleukin-6, procalcitonin and C-reactive protein levels in subjects with active Behçet''s disease

Background Erythrocyte sedimentation rate (ESR), C‐reactive protein (CRP) and cytokines, including serum interleukin (IL)‐6, IL‐8 and IL‐10, and tumour necrosis factor‐alpha (TNF‐α) have been proposed as disease activity markers in Behçet's disease (BD), although studies have shown conflicting results for IL‐6. Serum procalcitonin (PCT) levels in active BD have not yet been investigated. Objective The aim of the present study was to determine the reliability of serum IL‐6 and PCT levels as well as CRP as biological markers for activity of BD. Methods Serum PCT, IL‐6 and CRP protein levels were measured in patients with active BD (n = 15) and in healthy control subjects (n = 15). IL‐6 and PCT levels were measured in serum by chemiluminescent assay. In addition, a nephelometric method was used to analyse CRP concentrations in serum. Results Serum CRP and IL‐6 values were significantly higher in the subjects with active disease than in the healthy controls (P < 0.05), but there was no significant difference in the levels of PCT in the two groups. Conclusion The results of our study suggest that serum CRP and IL‐6 levels are elevated in patients with active BD, but that serum PCT values are not elevated in these patients.     

EFFICACY AND TOLERABILITY OF CEFDITOREN PIVOXIL IN UNCOMPLICATED SKIN AND SKIN STRUCTURE INFECTIONS IN INDIAN PATIENTS

Background:

Uncomplicated skin and skin structure infections (uSSSI) are commonly encountered community-acquired infections and are typically confined to the superficial layers of the skin. Hence, they seldom lead to the destruction of skin structures.

Aims:

To evaluate the efficacy and tolerability of cefditoren pivoxil in uSSSI in Indian patients.

Methods:

One hundred and seventy-eight patients diagnosed with uncomplicated SSSI were enrolled in this randomized, comparative, multicentric study. Patients received either cefditoren pivoxil or cefdinir for ten days. Efficacy was assessed both clinically and microbiologically. Safety evaluation consisted of reporting of type, frequency, severity, and causal relationship of adverse events.

Results:

One hundred and fifty-one patients completed the study. Clinical and bacteriological efficacy of cefditoren pivoxil was comparable to that of cefdinir in the treatment of uSSSI. One hundred and five patients were eligible for per protocol (PP) analysis of bacteriological outcome and clinical efficacy. Clinical cure or improvement was achieved in 98.00% patients treated with cefditoren pivoxil and 98.18% patients treated with cefdinir. In the modified Intent to Treat (mITT) patient population, clinical cure or improvement was recorded in 97.33% patients treated with cefditoren pivoxil and 96.20% patients treated with cefdinir. Microbiological eradication (or presumed eradication) was recorded in 88.00% patients treated with cefditoren pivoxil and 94.55% patients treated with cefdinir. The above differences in the outcome rates between the two drugs were not statistically significant. Six adverse events (AEs) (two in cefditoren group and four in cefdinir group) were reported in this study.

Conclusion:

Cefditoren pivoxil 200 mg b.i.d. was effective and well tolerated in the treatment of uSSSI.     

Skin microbiota: Friend or foe in pediatric skin health and skin disease

The human integument and gastrointestinal tract host unique microbial ecosystems. Within the last decade, research has focused on understanding the contributions of the microbiota to human health and disease. The majority of skin microbiome studies involve adults. This review focuses on key studies conducted within the pediatric population and provides a framework for future skin microbiome work in this ever‐expanding field. This article begins by exploring the skin microbiome at birth and reviews the impact of delivery mode on infant skin colonization. How skin microbial colonization evolves from infancy to adulthood and normal development impacts the abundance of skin commensals such as Streptococcus, Staphylococcus, and Cutibacterium is also highlighted. Finally, several skin microbiome research studies in common pediatric skin conditions are reviewed, including body odor, atopic dermatitis (AD), and acne. The bacteria involved in metabolizing sweat, the impact on body odor, and how this process evolves from childhood to adulthood is outlined. In AD, different bacteria genera that predominate in children and adults and the impact of current AD therapies on skin microbiota are explored. Finally, in acne, the understanding of how Cutibacterium acnes contributes to acne pathogenesis and how acne therapies impact the skin microbial communities is reviewed.     

Soybean-fragmented proteoglycans against skin aging

Objective: The majority of age-dependent skin changes happen in the dermis layer inducing changes in skin collagen and in the proteoglycans. The main aim of this work is to study the efficacy of a Proteum serum, containing soybean-fragmented proteoglycans, against skin aging. Materials and methods: In vitro tests were performed to evaluate the Proteum serum ability on activating the production of collagen and proteoglycans. An in vivo long-term study was performed to determine the efficacy of the Proteum serum when applied on skin. Protection of healthy skin against detergent-induced dermatitis and the antioxidant properties of the applied Proteum serum were also studied. Results and discussion: The in vitro tests demonstrated that the Proteum serum was able to elevate the production of molecules which are essential for supporting the dermal extracellular matrix organization. These results were correlated by the in vivo measurements where a clear trend on improving the measured skin parameters due to the Proteum serum application was found. Conclusions: A beneficial effect of the Proteum serum was demonstrated with an improvement in the skin roughness and a reinforcement of the skin barrier function. Moreover, a significant protector effect on human stratum corneum against lipids peroxides (LPO) was demonstrated.     

The physiological and phenotypic determinants of human tanning measured as change in skin colour following a single dose of ultraviolet B radiation

Please cite this paper as: The physiological and phenotypic determinants of human tanning measured as change in skin colour following a single dose of ultraviolet B radiation. Experimental Dermatology 2010; 19 : 667–673. Abstract: Experimental study of the in vivo kinetics of tanning in human skin has been limited by the difficulties in measuring changes in melanin pigmentation independent of the ultraviolet‐induced changes in erythema. The present study attempted to experimentally circumvent this issue. We have studied erythemal and tanning responses following a single exposure to a range of doses of ultraviolet B irradiation on the buttock and the lower back in 98 subjects. Erythema was assessed using reflectance techniques at 24 h and tanning measured as the L* spectrophotometric score at 7 days following noradrenaline iontophoresis. We show that dose (P < 0.0001), body site (P < 0.0001), skin colour (P < 0.0001), ancestry (P = 0.0074), phototype (P = 0.0019) and sex (P = 0.04) are all independent predictors of erythema. Quantitative estimates of the effects of these variables are reported, but the effects of ancestry and phototype do not appear solely explainable in terms of L* score. Dose (P < 0.0001), body site (P < 0.0001) and skin colour (P = 0.0365) or, as an alternative to skin colour, skin type (P = 0.0193) predict tanning, with those with lighter skin tanning slightly more to a defined UVB dose. If erythema is factored into the regression, then only dose and body site remain significant predictors of tanning: therefore neither phototype nor pigmentary factors, such as baseline skin colour, or eye or hair colour, predict change in skin colour to a unit erythemal response.     

Substantial skin disorders in psychiatric illness coincide with diabetes and addiction

Background Dermatological diseases in psychiatric patients are common; however, epidemiological data on this subject are scarce and to our knowledge integral studies of dermatological disease in psychiatric inpatients are not available yet. Aim The aim of this study was to describe the incidence of dermatological problems in psychiatric inpatients. Method This study evaluates the consultations for new dermatological problems by inpatients of a general psychiatric hospital of over 700 beds during a 6‐month period. Results A total of 255 patients consulted their physician because of a new dermatological problem. Diagnoses (n = 360) included skin infections (32%), accidents (7%), decubitus ulcers (7%), complications of medical treatment (3%), auto mutilation (1%) and neoplasms of the skin (1%). Patients with skin infections were likely to have diabetes [odds ratio (OR) = 3.6; 95% confidence interval (CI): 1.56–8.40]. Patients with decubitus ulcers were likely to have an addiction problem (OR = 6.4; 95% CI: 1.46–28.00). Dermatitis was associated with affective disorder (OR = 2.5; 95% CI: 1.12–5.43) but not with psychosis (OR = 0.5; 95% CI: 0.23–0.90). Only a poor correlation existed between the length of hospital stay and skin problems. Conclusions Dermatological problems are common in hospitalized psychiatric patients. Patients with diabetes mellitus are at high risk for skin infections. There are significant relationships between the psychiatric and the dermatological diagnoses. The length of the admission to a psychiatric hospital does not seem to play a major role in skin diseases.     

Treatment and prevention of community-associated methicillin-resistant Staphylococcus aureus skin and soft tissue infections

ABSTRACT:   Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged as a pathogen in the community with a range of clinical manifestations. Although skin and soft tissue infections (SSTIs) are the most common presentation, invasive and more virulent disease has been observed. Colonization and infection with CA-MRSA can occur in individuals with no prior healthcare exposures but also in distinct groups whose common characteristic appears to be close person-to-person contact. Outbreaks with CA-MRSA have occurred in day care centers, athletic teams, and prisons, and transmission has been documented among family members and within the hospital. Treatment of SSTIs involves incision and drainage, oral or parenteral antibiotic therapy, or topical therapy. Healthcare practitioners in outpatient and inpatient settings need to be familiar with prevention and treatment strategies for CA-MRSA.     

Does climate change affect the incidence of skin and allergic diseases in Germany?

Background: Skin diseases have great socio‐economic importance in Germany due to their high and in some cases still‐increasing prevalence. Little attention has yet been paid to the influence of the change in climate on these diseases. Objective: Clarify the evidence of the effects of climate change on the prevalence of skin diseases and allergies in Germany. Methods: First, a theoretical model of the possible mechanisms and influence factors of climate and weather was created for different disease groups (skin malignancies, allergies, skin infections). Then, a systematic online and manual literature search was made for model‐derived key words.The relevant publications were selected and evaluated according to a priori criteria. Results: From a total of n = 31,221 hits, n = 320 publications remained for evaluation.Changes in the following parameters can be regarded as essential climatologic factors influencing the prevalence of skin and allergic diseases: temperature, UV radiation, precipitation/humidity, cloudiness, and general weather conditions.There were only a few original articles addressed to this topic. Most of them address recurring phenomena (especially levels of airborne pollen), UV radiation or ozone (and the ozone hole). Quantitative statements, prognosis models and climate scenarios have not yet been published for Germany with respect to skin diseases. Conclusion: Only few scientific articles on the relationship between climate changes and the prevalence of skin diseases have been published. They do not allow a reliable statement on future developments. The outlook for changes in prevalence requires further clarification using published climate models.     

Effect of exposure of human skin to a dry environment

Background/aims: Changes in the skin conditions after exposure to low humidity have been generally experienced in everyday life, but there have been few reports to approach it—especially in healthy skin. We have examined the effect of low humidity on healthy human skin by using noninvasive measurement devices. Methods: Skin conditions on the ventral forearm and the cheek before and after 3 or 6 h exposure to low humidity were evaluated by measuring skin surface conductance, skin surface capacitance and transepidermal water loss. Skin surface replicas were also taken before and after exposure and analysed for roughness parameters—Ra (arithmetic mean roughness value), Rz (10-point height), Sm (mean value of the profile element) and VC1 (anisotropy of skin furrows). Results: There was a significant decrease of water content of stratum corneum at both test sites from the time points 0 h to 3 h and 6 h (P < 0.01) and transepidermal water loss from the time point 0 h to 6 h (P < 0.05). Regarding the roughness parameters, a significant increase of Rz in the directions of 45°/225° and 90°/270° to the body axis and Sm in the directions of 0°/180° (P < 0.05) on the forearm and VC1 (P < 0.05) on the cheek. The parameter Rz also showed a tendency to increase in the directions of 45°/225° (P = 0.06) on the cheek. A specific pattern of the changes to be related to the Langer's lines in the surface morphology was observed. The changes of skin surface pattern in our experiment lead us to consider that exposure to low humidity even in such a short period would be related to inducing aggravation of skin texture and the formation of fine wrinkles. Conclusion: A short exposure of skin to a low-humidity environment induced changes in the moisture contents in the stratum corneum and skin surface pattern, which lead us to assume that a dry environment in our daily life would make fine wrinkles related to lack of water in the stratum corneum.     

Cold plasma is well‐tolerated and does not disturb skin barrier or reduce skin moisture

Background: Cold plasma, a new treatment principle in dermatology based on ionic discharge delivering reactive molecular species and UV‐light, exhibits strong antimicrobial efficacy in vitro and in vivo. Before implementing plasma as new medical treatment tool, its safety must be proven, as well as assessing skin tolerance and patient acceptance. Patients and Methods: We investigated the plasma effects of three different plasma sources (pulsed, non‐pulsed atmospheric pressure plasma jet (APPJ) and a dielectric barrier discharge (DBD)) on the transepidermal water loss (TEWL) and skin moisture after treating the fingertips of four healthy male volunteers. Results: TEWL values were reduced by pulsed APPJ and DBD by about 20% but increased after non‐pulsed APPJ by 5–20%. TEWL values normalized 30 min after all forms of plasma treatment. Skin moisture was increased immediately and 30 min after treatment with pulsed APPJ but was not affected by non‐pulsed APPJ and DBD. Conclusions: All plasma treatments were well‐tolerated and did not damage the skin barrier nor cause skin dryness. Cold plasma fulfils basic recommendations for safe use on human skin and as future option may serve as the first physical skin antiseptic.     

Fractional CO2 laser resurfacing of photoaged facial and non-facial skin: Histologic and clinical results and side effects

Abstract

Background: CO₂ fractional ablation offers the potential for facial and non-facial skin resurfacing with minimal downtime and rapid recovery. Objectives: The purpose of this study was (i) to document the average depths and density of adnexal structures in non-lasered facial and non-facial body skin; (ii) to determine injury in ex vivo human thigh skin with varying fractional laser modes; and (iii) to evaluate the clinical safety and efficacy of treatments. Methods: Histologies were obtained from non-lasered facial and non-facial skin from 121 patients and from 14 samples of excised lasered thigh skin. Seventy-one patients were evaluated after varying energy (mJ) and density settings by superficial ablation, deeper penetration, and combined treatment. Results: Skin thickness and adnexal density in non-lasered skin exhibited variable ranges: epidermis (47–105 μm); papillary dermis (61–105 μm); reticular dermis (983–1986 μm); hair follicles (2–14/ HPF); sebaceous glands (2–23/HPF); sweat glands (2–7/HPF). Histological studies of samples from human thigh skin demonstrated that increased fluencies in the superficial, deep and combined mode resulted in predictable deeper levels of ablations and thermal injury. An increase in density settings results in total ablation of the epidermis. Clinical improvement of rhytids and pigmentations in facial and non-facial skin was proportional to increasing energy and density settings. Patient assessments and clinical gradings by the Wilcoxon's test of outcomes correlated with more aggressive settings. Conclusions: Prior knowledge of normal skin depths and adnexal densities, as well as ex vivo skin laser-injury profiles at varying fluencies and densities, improve the safety and efficiency of fractional CO₂ for photorejuvenation of facial and non-facial skin.     

In vivo skin measurements with a novel probe head for simultaneous skin impedance and near‐infrared spectroscopy

Background/purpose: Near‐infrared (NIR) spectroscopy and skin impedance (IMP) measurements are useful techniques for objective diagnostics of various skin diseases. Here, we present a combined probe head for simultaneous, time‐saving NIR spectroscopy and skin impedance measurements. The probe also ensures that both measurements are performed under equal conditions and at the same skin location. Methods: Finite element method simulations were performed for evaluation of the impedance. In vivo skin measurements were performed and combined NIR and impedance spectra were analysed by means of multivariate methods with respect to body location, age and gender. The classification rate was determined by a planar discriminant analysis. Reproducibility was investigated by calculation of scatter values and statistical significance between overlapping groups was assessed by the calculation of intra‐model distances, q. Results: The novel probe yielded rapid reproducible results and was easy to manage. Significant differences between skin locations and to a lesser extent age groups and gender were demonstrated. Conclusion: With the novel probe, statistically significant differences between overlapping classes in score plots can be confirmed by calculating intra‐model distances. The influence of molecular differences in the skin at different body locations is larger than the influence of gender or age and therefore relevant reference measurements are discussed.