Development of an improved method for quantitative analysis of skin blotting: increasing reliability and applicability for skin assessment

Sampling the skin surface chemistry for diagnosis and prognosis

Skin and wound blotting are non‐invasive techniques used to sample the skin and wound surface chemistry, whereby a nitrocellulose membrane is applied to an intact or broken cutaneous surface to detect biomarkers. However, there has been no comprehensive review of the evidence for the techniques used and data obtained to date. The primary aim of this study was to review the utilities of surface blotting for the diagnosis and prognosis of physiological, pre‐disease, and pathological states. The secondary aim was to summarise the procedural steps. A systematic literature search was conducted on 9 July 2021 using Medline, Embase, and Google Scholar databases. Investigators used McMaster's Critical Review Form for Quantitative Studies to assess quality, then performed a narrative synthesis reporting according to Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines. Twenty‐five studies were reviewed. Eighteen studies were of good quality, and seven were of moderate quality. These studies conducted skin and wound blotting on 176 animals and 1546 humans. Studies reported physiological and pathological states for diagnosis and prediction of conditions, including skin tears, wound healing, biofilm detection, and skin barrier function. The four steps for blotting are surface preparation, blot preparation, application and removal of blot, and analysis. This review demonstrates that blotting can determine the skin and wound surface chemistry using a versatile and reproducible technique. However, future research is needed to validate the technique and skin biomarkers identified.

Development of recurrent pressure ulcers, risk factors in older patients: a prospective observational study

Objective:

Prevention of recurrent pressure ulcers (PU) is one of the most important challenges in wound care, furthermore, the risk factors for recurrent PUs are still not fully understood. This study aimed to explore the risk factors for recurrent PU development within two weeks, including biophysical skin properties, pro-inflammatory cytokine (tumour necrosis factor [TNF]-α) levels and bacterial species, in older patients.

Method:

This prospective study was conducted in a long-term care facility with patients whose PU had healed within two months. Biophysical skin properties were evaluated by stratum corneum hydration, pH, sebum content and transepidermal water loss. TNF-α level was measured using skin blotting. Skin bacteria were collected using tape stripping and determined by species-specific gene amplification. These parameters, along with Braden scale and interface pressure, were evaluated every two weeks for a total period of eight weeks. A penalised generalised estimating equation analysis was used to determine the risk factors for recurrent PUs.

Results:

In total, 20 patients were included in this study, with 57 observations. Of these, recurrent PU was seen in eight observations. Elevation of pH (p=0.049; odds ratio [OR] per 1 unit=3.91, 95% confidence interval [CI]:1.01–15.15), presence of Acinetobacter spp. (p=0.039; OR versus culture-negative=6.28, 95%CI:1.10–35.86) and higher interface pressure (p=0.008; OR per 1 mmHg=1.06, 95%CI:1.01–1.10) on the healed PU were significantly related to the development of recurrent PU.

Conclusion:

Higher pH, existence of Acinetobacter spp. and higher interface pressure on the site of the healed PU were associated with the development of recurrent PUs in older patients undergoing conservative treatments.