Bacterial invasion into the epidermis of rats with sodium lauryl sulphate-irritated skin increases damage and induces incontinence-associated dermatitis.

Incontinence-associated dermatitis (IAD) is caused by prolonged exposure to urine/liquid stool. It is a common and often painful skin condition in older incontinent adults because of poor prevention. Patients with urinary infections are at risk of developing IAD, and to guide the development of novel prevention strategies, we aimed to develop an animal model of IAD by urine and bacteria. First, contralateral sites on the dorsal skin of Sprague-Dawley rats were compromised by sodium lauryl sulphate (SLS), simulating frequent cleansing with soap/water. Filter discs were then placed inside ring-shaped chambers on foam dressings, inoculated with or without Pseudomonas aeruginosa, covered with agarose gels immersed in cultured filtrated urine, and secured in place with an occlusive dressing for 3 days. Untreated and SLS-compromised sites served as controls. The IAD was developed at bacteria-inoculated sites, characterised by severe IAD-like redness that persisted for up to 3 days post-exposure and higher disruption of the skin barrier function compared with non-inoculated sites. Pathological changes included epidermal thickening, partial skin loss, inflammatory cell infiltration, accumulation of red blood cells, and invasion of bacteria into the epidermis. This novel, clinically relevant IAD rat model can serve for future prevention developments.

Promoting effect of acylated homoserine lactone on the healing of tissue damage in model rats with incontinence-associated dermatitis.

OBJECTIVE: One of the most common complications in patients with incontinence is incontinence-associated dermatitis (IAD). This study was conducted to determine the pathophysiology of the healing process of IAD and to develop an effective therapeutic approach according to its pathophysiology. METHOD: IAD was reproduced on a dorsal rat skin by applying agarose gel containing water and enzymes, and inoculating it with bacteria. Examination of the IAD healing process suggested that the promotion of keratinocyte migration and improvement of basement membrane enhance keratinocyte layer elongations, which contribute to IAD healing. A therapeutic approach using N-(3-oxotetradecanoyl)-L-homoserine lactone, which is one of the acylated homoserine lactones (AHLs) and can promote keratinocyte migration in vitro, was applied on the IAD area in rats. RESULTS: AHL treatment after IAD development resulted in an earlier tipping point for recovery than the vehicle treatment. Histological and immunohistological analyses revealed that the tissue surface was already covered by the epidermis, indicating the results of elongation of the keratinocyte layer from hair follicles. The characteristics of the alignment of basal keratinocytes, the existence of stratum corneum, and the membrane-like distribution of the components of basement membrane were similar to those of a normal epidermis. CONCLUSION: These results suggested that AHL application possibly contributed to earlier IAD healing before progressing to a severe state. Although elongation of the keratinocyte layer was observed in both the AHL and vehicle groups, the possibility that AHL application promotes IAD healing was suggested. The new concept of the enhancement of keratinocyte migration as a therapeutic approach for IAD would change the skin care strategy for IAD in the healthcare setting.

Concurrent validity of biofilm detection by wound blotting on hard-to-heal wounds.

OBJECTIVE: Wound biofilms delay healing of hard-to-heal wounds. Convenient biofilm identification tools for clinical settings are currently not available, hindering biofilm-based wound management. Wound blotting with biofilm staining is a potential tool for biofilm detection, owing to its convenience. Although predictive validity of wound blotting has been established, it is necessary to confirm its concurrent validity. Furthermore, current staining systems employing ruthenium red have some disadvantages for clinical use. This study aimed to evaluate the usability of alcian blue as a substitute for ruthenium red. METHOD: Both in vitro and in vivo clinical samples were used to investigate validity and usability. RESULTS: The in vitro study showed that proteins and extracellular DNA in biofilms did not affect staining ability of ruthenium red and alcian blue in the detection of biofilms. In the in vivo study, using a wound biofilm model with Pseudomonas aeruginosa, the staining sensitivity of ruthenium red was 88.9% and 100% for alcian blue, with correlation coefficients of signal intensities with native polyacrylamide gel electrophoresis (PAGE) of r=0.67 (p=0.035) and r=0.67 (p=0.036) for ruthenium red and alcian blue, respectively. Results from clinical samples were r=0.75 (p=0.001) for ruthenium red and r=0.77 (p<0.001) for alcian blue. The sensitivities of wound blotting staining by ruthenium red and alcian blue were very high and had a good correlation with native PAGE analysis. CONCLUSION: Because the alcian blue procedure is more convenient than the ruthenium red procedure, wound blotting with alcian blue staining would be a promising tool to guide clinicians in delivering biofilm-based wound management.

Does the presence of bacterial urinary infection contribute to the development of incontinence-associated dermatitis? A scoping review.

OBJECTIVE: Incontinence-associated dermatitis (IAD) is an inflammatory skin condition caused by the repeated exposure to urine and faeces. It is not common for urinary incontinence only to cause IAD, however patients with urinary tract infections (UTIs) are also at increased risk for IAD. This scoping review aimed to provide a summary of the relationship between bacterial urinary infections and IAD. METHODS: We conducted a scoping review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. PubMed, CINAHL, Medline, and Web of Science were searched for relevant articles from January 2007 through February 2020. RESULTS: Based on eligibility criteria, 13 research studies and review articles were included. Despite the acknowledged role of bacterial infections can play in IAD and the importance of eradicating infections for the prevention of skin breakdown, there have been limited studies that have investigated how uropathogenic bacteria, in combination with urine, lead to skin damage and IAD. The use of urinary catheters also predisposes to UTIs; however, prevalence/incidence rates of IAD in these patients are not clear, as they were considered as continent of urine in the included studies. CONCLUSION: Further research is needed to elucidate the mechanisms of how bacteria, in combination with urine, lead to IAD.

Assessing absorbent products' effectiveness for the prevention and management of incontinence-associated dermatitis caused by urinary, faecal or double adult incontinence: A systematic review.

OBJECTIVE: Adults who suffer from incontinence are at substantial risk of developing incontinence-associated dermatitis (IAD). In healthcare settings, several interventions have been implemented to prevent or manage IAD, and several absorbent products have been developed for incontinent patients; however, there is no systematic review that has reported on which absorbent products are effective for the prevention or management of incontinence-associated dermatitis. We conducted a systematic review to investigate the effectiveness of absorbent products in the prevention and management of IAD. METHODS: MEDLINE (1946-August 31, 2020), CINAHL (1982-August 31, 2020), and Cochrane Library (August 31, 2020) were searched for relevant articles. RESULTS: Eight studies met the eligibility criteria and were included in this review, including two randomized controlled trials that were designed to evaluate the efficacy of absorbent products on the prevention or management of incontinence-associated dermatitis. Quality of evidence was assessed as low or very low. The findings revealed that some outcomes related to IAD prevention or improvement of IAD can be positively affected by the introduction of a new absorbent product or a difference in the frequency of pad changing, which can control the overhydration of the skin. CONCLUSIONS: The studies included in this review indicated that the problem of control of overhydration of the skin associated with urine and/or faeces can be controlled by absorbent products and these products may be effective for the prevention or management of incontinence-associated dermatitis. Future research with high-quality studies is required.

Combination of urease inhibitor and antiseptic inhibits urea decomposition-induced ammonia production by Proteus mirabilis.

The decomposition of urea into ammonia by urease-producing bacterium shows an elevation in the pH level, which can lead to incontinence-associated dermatitis (IAD). This study aimed to examine the efficacy of a combination of antiseptic and urease inhibitor in inhibiting the decomposition of urea by the urease-producing bacterium Proteus mirabilis. We performed in vitro assays to compare the effects of a combination of antiseptic and urease inhibitor, antiseptic only, urease inhibitor only, and an untreated control with the effects of a urea-containing solution. Cultured P. mirabilis was mixed with urea-containing solution, followed by the addition of antiseptic and/or urease inhibitor. The main outcome used to assess the efficacy of the different treatments was ammonia concentration at 4-hours post-treatment initiation, and multiple comparison analysis was performed using Dunnett's test to compare the results between groups. Ammonia concentrations in samples treated with either antiseptic or urease inhibitor were lower than those in the untreated control, while the combination of antiseptic and urease inhibitor resulted in decreased ammonia concentrations compared with either treatment alone. Therefore, the application of both urease inhibitor and antiseptic is more effective for the inhibition of urea decomposition by urease-producing bacteria. Novel preventive strategies using these reagents may be effective for preventing IAD.

Influence of digestive enzymes on development of incontinence-associated dermatitis: Inner tissue damage and skin barrier impairment caused by lipidolytic enzymes and proteases in rat macerated skin.

One of the most common complications in patients with incontinence is incontinence-associated dermatitis. This study aimed to examine the influences of lipidolytic enzymes and/or proteases on skin barrier and tissue structure on the development of incontinence-associated dermatitis. Two animal experiments, ex vivo and in vivo, were performed using rats to examine the influences of 3 factors (maceration, proteases, and lipidolytic enzymes) alone or in various combinations on the barrier function and histology of the skin. As a result, skin treatments, including both of the skin maceration and proteases application, caused erythrocyte leakage from the blood vessels in the dermis. The erythrocyte leakage was observed in a larger area in the skin treated with proteases and lipidolytic enzymes with maceration than in the skin treated with proteases with maceration, that is, the addition of lipidolytic enzymes to skin maceration with proteases enhanced erythrocyte leakage. Lipidolytic enzymes in macerated skin are factors that accelerate tissue damage via skin barrier impairment, and proteases are the factors that trigger the development of incontinence-associated dermatitis via tissue damage. Advanced nursing care of perineal skin in patients with faecal incontinence is required because of the deleterious influence of lipidolytic enzymes and proteases.

The Association between Tinea Pedis and Feet-Washing Behavior in Patients with Diabetes: A Cross-sectional Study.

OBJECTIVES: To examine the correlations between elements of feet-washing behavior, presence of tinea pedis (TP), and patients' background characteristics in order to identify a concrete intervention method to prevent TP. DESIGN AND PARTICIPANTS: A cross-sectional study of 30 patients with diabetes (16 with TP) who were admitted to or visited the university hospital. MAIN OUTCOME MEASURES: The presence of TP was confirmed by the detection of dermatophytes by direct microscopy. Data on elements of feet-washing behavior, such as scrubbing between the toes, were collected by observing recorded videos of participants normally washing their feet as they do at home. The patients' background characteristics included demographic data; diabetes-related factors; patient knowledge regarding diabetes, foot problems, and TP prevention; purpose for feet washing; and any difficulties in feet washing. MAIN RESULTS: The number of times patients scrubbed between their toes while washing with soap was significantly lower in patients with TP (odds ratio, 0.95; P = .036; with a cutoff value of 35 times) and those who had difficulty in reaching their feet with their hands (B = -14.42, P = .041). CONCLUSIONS: An effective foot-washing protocol should include specific instructions for patients to scrub between their toes at least 35 times in all 8 spaces while washing with soap. Appropriate advice is also needed for individuals who have difficulty reaching their feet with their hands. Education about appropriate foot-washing behavior may potentially prevent TP.

Telogen elongation in the hair cycle of ob/ob mice.

Alopecia impairs the physical and mental health of patients. We have previously shown that 8-week-old ob/ob mice have no reactivity to depilation, which is a stimulus that induces anagen transition in normal mice, while no hair cycle abnormalities have been reported in other studies until mice reach 7 weeks of age. Therefore, we hypothesized that ob/ob mice have abnormalities in hair cycle progression beyond 7 weeks of age. We examined 6- to 24-week-old ob/ob and 6- to 10-week-old normal mice. After acclimation, the dorsal skin was harvested and the hair cycle phase was identified histologically and immunohistochemically. Normal mice showed catagen-telogen and telogen-anagen transitions at 6 and 8-9 weeks old, respectively. In contrast, the anagen-catagen transition was observed in 7-week-old mice and the telogen phase was maintained from 10 to 24 weeks in most ob/ob mice. These results suggests that ob/ob mice are a possible model animal for telogen effluvium.

Lower temperature at the wound edge detected by thermography predicts undermining development in pressure ulcers: a pilot study.

Undermined pressure ulcers (PUs) are troublesome complications that are likely to delay wound healing. Early skin incision and debridement can prevent the deterioration of undermined PUs, thus it is necessary to identify devitalised tissue areas to determine the appropriate timing for such interventions. This retrospective cohort study evaluated whether a lower temperature at the wound edge than the wound bed and periwound skin, detected by thermography, can predict undermining development in PUs 1 week after the assessment. Twenty-two participants with category III, IV, or unstageable PUs who were examined by interdisciplinary PU team and were followed up for at least two consecutive weeks were analysed. We found 9/11 PUs without a lower temperature at the wound edge did not develop undermining development, whereas 8/11 PUs with the lower temperature did develop undermining. The relative risk of undermining development after 1 week in PUs with the lower temperature was 4·00 (95% confidence intervals: 1·08-14·7). The sensitivity, specificity, positive predictive value and negative predictive value were 0·80, 0·75, 0·73 and 0·81, respectively. A thermal imaging assessment focusing on a lower temperature pattern at the wound edge may provide sufficient information to predict undermining development.

Exploring the prevalence of skin tears and skin properties related to skin tears in elderly patients at a long-term medical facility in Japan.

The identification of appropriate skin tear prevention guidelines for the elderly requires clinicians to focus on local risk factors such as structural alterations of the epidermis and dermis related to skin tears. The aim of this cross-sectional study is to explore the prevalence of skin tears and to explore skin properties related to skin tears in elderly Japanese patients at a long-term medical facility. After doing the prevalence study, 18 participants with skin tears and 18 without were recruited and an evaluation of their skin properties using 20-MHz ultrasonography, skin blotting and also Corneometer CM-825, Skin-pH-meterPH905, VapoMeter, Moisture Meter-D and CutometerMPA580 was undertaken. A total of 410 patients were examined, the median age was 87 years and 73·2% were women. The prevalence of skin tears was 3·9%, and 50% of skin tears occurred on the dorsal forearm. The changes in skin properties associated with skin tears included increased low-echogenic pixels (LEP) by 20-MHz ultrasonography, decreased type IV collagen and matrix metalloproteinase-2, and increased tumour necrosis factor-α by skin blotting. In conclusion, this study suggests that increased dermal LEP, including solar elastosis, may represent a risk factor for skin tears; this indicates that skin tear risk factors might not only represent chronological ageing but also photoageing.

Skin blotting: a noninvasive technique for evaluating physiological skin status.

OBJECTIVE: The skin performs important structural and physiological functions, and skin assessment represents an important step in identifying skin problems. Although noninvasive techniques for assessing skin status exist, no such techniques for monitoring its physiological status are available. This study aimed to develop a novel skin-assessment technique known as skin blotting, based on the leakage of secreted proteins from inside the skin following overhydration in mice. The applicability of this technique was further investigated in a clinical setting. DESIGN: Skin blotting involves 2 steps: collecting proteins by attaching a damp nitrocellulose membrane to the surface of the skin, and immunostaining the collected proteins. The authors implanted fluorescein-conjugated dextran (F-DEX)-containing agarose gels into mice and detected the tissue distribution of F-DEX under different blotting conditions. They also analyzed the correlations between inflammatory cytokine secretion and leakage following ultraviolet irradiation in mice and in relation to body mass index in humans. MAIN RESULTS: The F-DEX in mice was distributed in the deeper and shallower layers of skin and leaked through the transfollicular and transepidermal routes, respectively. Ultraviolet irradiation induced tumor necrosis factor secretion in the epidermis in mice, which was detected by skin blotting, whereas follicular tumor necrosis factor was associated with body mass index in obese human subjects. These results support the applicability of skin blotting for skin assessment. CONCLUSIONS: Skin blotting represents a noninvasive technique for assessing skin physiology and has potential as a predictive and diagnostic tool for skin disorders.

Estimation of Wound Area and Severity Level of Skin tear using Deep Learning Methods.

Skin tears occur mainly in older adults, making it difficult to identify the wound area and severity level when making care decision. We propose an algorithm for estimating the wound area and severity level of skin tears using a deep learning method. In this study, U-Net was used to estimate the skin tear area and VGG16 was used to estimate the severity level. The deep learning method shows an Intersection of Union (IoU) of 0.58 and 0.65 in estimating wound areas and purpura areas, and 62.2% accuracy in estimating severity levels. The proposed method outperforms the previous method using a classical machine learning method. This indicates that the proposed deep learning method is promising for image processing for skin tears, even if the skin tears include narrow wound edges and flaps, which are difficult to distinguish from the wound area.Clinical relevance-The proposed method can automatically estimate the area and severity level of skin tears to assist caregivers who are unfamiliar with skin tears.

Japanese clinical practice guidelines for aspiration and pharyngeal residual assessment during eating and swallowing for nursing care.

AIM: This clinical practice guideline aims to provide and recommend methods of assessing aspiration and pharyngeal residue during eating and swallowing and methods of selecting and implementing nursing care for adults to prevent the development of aspiration pneumonia through early and appropriate management of oropharyngeal dysphagia. METHODS: In April 2018, the Japan Academy of Nursing Science established the Supervisory Committee in Nursing Care Development/Standardization Committee to develop clinical practice guidelines for aspiration and pharyngeal residual assessment during eating and swallowing for nursing care. This clinical practice guideline was developed according to the Minds Manual for Guideline Development 2017, with the aim of providing a specific pathway for nurses to determine the policy for selecting management for oropharyngeal dysphagia based on research evidence and multifaceted factors including the balance of benefits and harms and patients' values. RESULTS: Based on the 10 clinical questions related to assessment by physical assessment, the Repetitive Saliva Swallowing Test, Modified Water Swallowing Test, Food Test, cervical auscultation, observation using an ultrasound diagnostic device, and an endoscope, 10 recommendations have been developed. Eight recommendations have been evaluated as the Grading of Recommendations Assessment, Development and Evaluation (GRADE) 2C, and the other two have been evaluated as no GRADE. CONCLUSION: The first reliable clinical practice guideline has been produced from an academic nursing organization that focuses on assessment for nursing care and incorporates the latest findings.

Effects of improved hypoallergenic fabrics in medical wigs in patients with breast cancer with chemotherapy-induced alopecia: a randomised clinical trial.

PURPOSE: Chemotherapy causes changes in appearance in patients with cancer. Therefore, to have a normal life, it is necessary for patients to wear a wig. However, wearing a wig may strain an already sensitive scalp during chemotherapy. This study aimed to assess the effects of a hypoallergenic medical wig in breast cancer patients with chemotherapy-induced alopecia (CIA). METHODS: A randomised, single-blind, controlled study was conducted from January 2015 to July 2017 in Tokyo, Japan. Women with non-metastatic breast cancers were enrolled. Participants were provided a hypoallergenic medical wig or a traditional medical wig. The primary endpoint was incidence of scalp dermatitis, including erythema, rash and erosion. The secondary endpoints were incidence of scalp symptoms, alterations in scalp barrier functions and quality of life (QOL). Patients were followed at the start of the first chemotherapy administration and at 13th week. RESULTS: Fifty-nine women were included in the analysis. At 13th week, the incidence of erythema was 44.8% among patients in the intervention group and 86.7% among patients in the control group, in the intention-to-treat analysis (p<0.01). The incidence of erosion tended to decrease in the intervention group at the 13th week (p=0.09). The incidence of scalp symptoms, alterations in scalp barrier functions and QOL were not significantly different between the groups. CONCLUSIONS: The incidence of dermatitis, including erythema, rash and erosion, decreased when wearing the new hypoallergenic medical wig. The gentle hypoallergenic medical wig is useful in improving erythema in cancer patients with CIA.Trial registration number UMIN000021289.

Diagnostic accuracy of ultrasound examination in detecting aspiration and pharyngeal residue in patients with dysphagia: A systematic review and meta-analysis.

AIM: To estimate diagnostic accuracy of ultrasonography for detecting aspiration and pharyngeal residue in patients with dysphagia. METHODS: A systematic search was conducted in MEDLINE (via PubMed), CINAHL, EMBASE, Ichushi-Web, and Cochrane Library databases to identify articles that showed diagnostic accuracy of ultrasonography for detecting aspiration and residue published in English and Japanese until August 2019. Cross-sectional studies, case-control studies, and cohort studies were included. The diagnostic accuracy results were extracted and the pooled estimated sensitivity and specificity were calculated. The risk of bias of the studies was assessed using the Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies 2. The certainty of the evidence was assessed using the Grades of Recommendation Assessment, Development, and Evaluation methodology. RESULTS: Five studies were included in this review. The pooled estimated sensitivity and specificity for detecting aspiration were 0.82 (95% CI: 0.72-0.89) and 0.87 (95% CI: 0.81-0.92), respectively. One study was included that evaluated ultrasound assessments of pharyngeal residue. The sensitivity and specificity were 0.62 (95% CI: 0.32-0.86) and 0.67 (95% CI: 0.22-0.96), respectively. The certainty of the evidence was low and very low for the diagnostic accuracy of aspiration and pharyngeal residue, respectively. CONCLUSION: Ultrasound is a non-invasive method with good sensitivity and specificity in detecting aspiration as well as reference standards. While risk of bias and small number of studies limited the strength of this systematic review, our results suggested that ultrasound examination was useful as a bedside screening tool for detecting aspiration.

Effects of skin care education for care staff at elderly care facilities on skin conditions of the residents.

Asteatosis is common in elderly people due to a decrease in the moisture content of the epidermal stratum corneum through a loss of skin barrier function caused by aging. Because itching often accompanies asteatosis, this condition may cause a decrease in quality of life. Care staff in elderly care facilities have many opportunities to provide care for residents. In this study, we examined how educational training on skin care changed the thoughts and actions of care staff in these facilities and how these changes impacted the skin conditions of residents. The subjects for the training were all care staff in facilities because these staff work most closely with facility residents. We performed skin care training for the subjects and investigated changes in the skin conditions of the residents before and after the training. The training promoted the understanding of skin care among the care staff and improved the skin symptoms of residents with asteatosis. However, there were no changes in the severity of itchiness based on a verbal rating scale and in interviews of residents. This study showed that skin care training for the care staff in facilities is effective to improve skin conditions of residents. In addition, it was suggested that a full grasp of the residents' skin symptoms based upon an interview on itching alone was difficult, and thus there is a need to observe skin conditions directly.

The relationship between malignant wound status and pain in breast cancer patients.

PURPOSE: Skin metastasis is one of the most frequent metastases in breast cancer patients. Patients with malignant wounds experience numerous symptoms, including serious wound pain. However, the features of pain related to malignant wounds have not been investigated. Nurses can experience a dilemma when treating these patients due to a lack of knowledge of the pain. The aims of this study were to examine the quality and intensity of malignant wound pain and to determine the association between wound status and pain in the patients with malignant wounds. METHODS: Cross-sectional study was conducted. Participants were recruited from a breast centre based in a general hospital. We collected the patients' demographic and wound management data and assessed wound condition. Patients evaluated wound pain intensity and quality over the preceding week using the short-form McGill Pain Questionnaire (SF-MPQ). The association between SF-MPQ results, wound condition, and the time interval for wound care was evaluated using the Spearman's correlation coefficient. The protocol was approved by the Ethical Committee of the each facilities. RESULTS: The median age of the 22 enrolled patients was 61.5 years, and the median time after diagnosis of malignant wound was 15.5 months. Overall, 77.3% of patients complained of pain. Malignant wound pain significantly correlated with the degradation of wound edges, granulation tissue, and the time interval for wound care. CONCLUSION: We consider that it is necessary to provide pain-control care focused on the wound edge and granulation tissue of malignant wounds through the assessment of malignant wound pain and condition.

Topical Administration of Acylated Homoserine Lactone Improves Epithelialization of Cutaneous Wounds in Hyperglycaemic Rats.

Clinicians often experience delayed epithelialization in diabetic patients, for which a high glucose condition is one of the causes. However, the mechanisms underlying delayed wound closure have not been fully elucidated, and effective treatments to enhance epithelialization in patients with hyperglycaemia have not been established. Here we propose a new reagent, acylated homoserine lactone (AHL), to improve the delayed epithelialization due to the disordered formation of a basement membrane of epidermis in hyperglycaemic rats. Acute hyperglycaemia was induced by streptozotocin injection in this experiment. Full thickness wounds were created on the flanks of hyperglycaemic or control rats. Histochemical and immunohistochemical analyses were performed to identify hyperglycaemia-specific abnormalities in epidermal regeneration by comparison between groups. We then examined the effects of AHL on delayed epithelialization in hyperglycaemic rats. Histological analysis showed the significantly shorter epithelializing tissue (P < 0.05), abnormal structure of basement membrane (fragmentation and immaturity), and hypo- and hyperproliferation of basal keratinocytes in hyperglycaemic rats. Treating the wound with AHL resulted in the decreased abnormalities of basement membrane, normal distribution of proliferating epidermal keratinocytes, and significantly promoted epithelialization (P < 0.05) in hyperglycemic rats, suggesting the improving effects of AHL on abnormal epithelialization due to hyperglycemia.

Histopathology of Incontinence-Associated Skin Lesions: Inner Tissue Damage Due to Invasion of Proteolytic Enzymes and Bacteria in Macerated Rat Skin.

A common complication in patients with incontinence is perineal skin lesions, which are recognized as a form of dermatitis. In these patients, perineal skin is exposed to digestive enzymes and intestinal bacterial flora, as well as excessive water. The relative contributions of digestive enzymes and intestinal bacterial flora to skin lesion formation have not been fully shown. This study was conducted to reveal the process of histopathological changes caused by proteases and bacterial inoculation in skin maceration. For skin maceration, agarose gel containing proteases was applied to the dorsal skin of male Sprague-Dawley rats for 4 h, followed by Pseudomonas aeruginosa inoculation for 30 min. Macroscopic changes, histological changes, bacterial distribution, inflammatory response, and keratinocyte proliferation and differentiation were examined. Proteases induced digestion in the prickle cell layer of the epidermis, and slight bleeding in the papillary dermis and around hair follicles in the macerated skin without macroscopic evidence of erosion. Bacterial inoculation of the skin macerated by proteolytic solution resulted in the formation of bacteria-rich clusters comprising numerous microorganisms and inflammatory cells within the papillary dermis, with remarkable tissue damage around the clusters. Tissue damage expanded by day 2. On day 3, the proliferative keratinocyte layer was elongated from the bulge region of the hair follicles. Application of proteases and P. aeruginosa induced skin lesion formation internally without macroscopic erosion of the overhydrated area, suggesting that the histopathology might be different from regular dermatitis. The healing process of this lesion is similar to transepidermal elimination.