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.

Development of a method to identify persistent and blanchable redness by skin blotting in mice.

Persistent and blanchable redness (PBR) is not currently included in category I pressure injury (PI), which is defined as non-blanchable redness (NBR). However, PBR progresses to PI in a clinical setting. Therefore, it should be clinically managed as category I PI, and a method to distinctly identify PBR is needed. This study aimed to examine whether PI-related biomarkers can distinguish PRB from transient redness (TR) and NBR using skin blotting. TR, PBR, and NBR models were established by the different conditions of dorsal skin compression. Redness observation and skin blotting were performed, and the skin tissue samples were subjected to histological and molecular biological analyses. The vascular endothelial growth factor (Vegf) b, heat shock protein (Hsp) 90aa1, tumour necrosis factor, interleukin (Il) 1b, and Il6 messenger ribonucleic acid levels were significantly different between the three models. The VEGF-A, VEGF-B, IL-1ß, and IL-6 protein levels were different between the three models. Although the results of skin blot examinations were inconsistent with those of the expression analysis of tissue, HSP90α and IL-1ß are suggested to be potential markers to distinguish PBR from TR and NBR.

Identification of microRNAs responsive to shear loading in rat skin.

Pressure injuries (PIs) are localised skin injuries that result from pressure with or without shear force. Shear force is more destructive than pressure in clinical settings. Therefore, determining the critical external forces is important for selecting the appropriate care to prevent PIs. To quantitatively distinguish pressure and shear loading with high specificity, we focused on microRNAs (miRs). This study aimed to identify the miRs that are distinguishable between pressure with and without shear loading in rat skin. Microarray analysis identified six candidate miRs from the comparisons among the pressure, shear, and unloaded groups. We analysed the expression levels of the candidate miRs in the process of PI development using real-time reverse transcriptase polymerase chain reaction. In the pressure and shear groups, miR-92b expressions at 6 hours after loading were 2.3 ± 1.3 and 2.9 ± 1.0, respectively, which were significantly higher than those in the control group (P = .014 and .004, respectively). miR-877 expression at 6 hours after loading was significantly increased only in the shear group (2.8 ± 0.9) compared with the control group (P = .016). These results indicate that miR-92b and miR-877 are promising biomarkers to determine for which external force healthcare professionals should intervene.

Risk scoring tool for forearm skin tears in Japanese older adults: A prospective cohort study.

[Aim] Because painful skin tears frequently occur in older patients, the prevention of skin tears is fundamental to improve their quality of life. However, a risk assessment tool for skin tears has not been established yet in Japan. Therefore, we aimed to propose a risk scoring tool for skin tears in Japanese older adult. [Methods] We conducted a prospective cohort study with 6-month follow-up in two long-term care hospitals in Japan. A total of 257 inpatients were recruited. Patient and skin characteristics were collected at baseline, and the occurrence of forearm skin tears were examined during follow-up. To develop a risk scoring tool, we identified risk factors, and converted their coefficients estimated in the multiple logistic regression analysis into simplified scores. The predictive accuracy of the total score was evaluated. [Results] Of 244 participants, 29 developed forearm skin tears during the follow-up period, a cumulative incidence of 13.5%. Senile purpura, pseudoscar, contracture, and dry skin were identified as risk factors for skin tears. Their weighted scores were 6, 4, 5, and 6, respectively. The area under the receiver operating characteristic curve of the total score was 0.806. At a cut-off score of 12, the sensitivity was 0.86, and the specificity was 0.67. [Conclusion] Our forearm skin tear risk scoring tool showed high accuracy, whereas specificity was low. This tool can contribute to prevent forearm skin tears in Japanese older adults.

Prediction of healing in Category I pressure ulcers by skin blotting with plasminogen activator inhibitor 1, interleukin-1α, vascular endothelial growth factor C, and heat shock protein 90α: A pilot study.

The prevention of progression of Category I pressure ulcers (PUs) to Category II or higher is important, as Category II or higher PUs are open wounds and have a higher infection risk. Prognosis prediction of Category I PUs is necessary to provide successful intensive care for PUs with impaired healing. We focused on skin blotting using plasminogen activator inhibitor 1 (PAI1), interleukin-1α (IL-1α), vascular endothelial growth factor C (VEGF-C), and heat shock protein 90α (HSP90α). This pilot study was conducted at long-term-care and general hospitals to examine the applicability of DESIGN-R and thermography; the feasibility of skin blotting technique; the biomarker candidates, PAI1, IL-1α, VEGF-C, and HSP90α; and sample size for prognosis prediction for Category I PUs. Patients aged >65 years underwent skin blotting, scoring for DESIGN-R, and took thermography images of their Category I PU site. Albumin signals were not detected in one out of three participants. PAI1, IL-1α, VEGF-C, and HSP90α were detected in 19 participants, among whom 11 participants could be followed up after one week. There was no difference in DESIGN-R score and skin surface temperature between normal and impaired healing groups, and the sample size was calculated as 16. In conclusion, the feasibility of skin blotting was confirmed. PAI1, IL-1α, VEGF-C, and HSP90α could be biomarker candidates for prognosis prediction for Category I PU and the combination of VEGF-C and HSP90α could be associated with the prognosis of Category I PU. We need to investigate 842 patients in a future study.