Validity of skin blot examination for albumin and nerve growth factor β to detect itching of the skin in Indonesian older adults

An Overview of Growth Factors as the Potential Link between Psoriasis and Metabolic Syndrome

Psoriasis is a chronic, complex, and immunologically mediated systemic disease that not only affects the skin, but also the joints and nails. It may coexist with various other disorders, such as depression, psoriatic arthritis, cardiovascular diseases, diabetes mellitus, and metabolic syndrome. In particular, the potential link between psoriasis and metabolic syndrome is an issue worthy of attention. The dysregulation of growth factors could potentially contribute to the disturbances of keratinocyte proliferation, inflammation, and itch severity. However, the pathophysiology of psoriasis and its comorbidities, such as metabolic syndrome, remains incompletely elucidated. Growth factors and their abnormal metabolism may be a potential link connecting these conditions. Overall, the objective of this review is to analyze the role of growth factor disturbances in both psoriasis and metabolic syndrome.

Basic mechanisms of itch

Pruritus (or itch) is an unpleasant sensation leading to a desire to scratch. In the epidermis, there are selective C or Aδ epidermal nerve endings that are pruriceptors. At their other ends, peripheral neurons form synapses with spinal neurons and interneurons. Many areas in the central nervous system are involved in itch processing. Although itch does not occur solely because of parasitic, allergic, or immunologic diseases, it is usually the consequence of neuroimmune interactions. Histamine is involved in a minority of itchy conditions, and many other mediators play a role: cytokines (eg, IL-4, IL-13, IL-31, IL-33, and thymic stromal lymphopoietin), neurotransmitters (eg, substance P, calcitonin gene-related peptide, vasoactive intestinal peptide, neuropeptide Y, NBNP, endothelin 1, and gastrin-releasing peptide), and neurotrophins (eg, nerve growth factor and brain-derived neurotrophic factor). Moreover, ion channels such as voltage-gated sodium channels, transient receptor potential vanilloid 1, transient receptor ankyrin, and transient receptor potential cation channel subfamily M (melastatin) member 8 play a crucial role. The main markers of nonhistaminergic pruriceptors are PAR-2 and MrgprX2. A notable phenomenon is the sensitization to pruritus, in which regardless of the initial cause of pruritus, there is an increased responsiveness of peripheral and central pruriceptive neurons to their normal or subthreshold afferent input in the context of chronic itch.

Which objective itch-assessment tools are applicable to patients with advanced cognitive impairments? A scoping review

BACKGROUND

Itching is an irritating and uncomfortable sensation that has a profound effect on patients' physical and mental health. It is a major under-recognised problem in older patients who cannot express their pain due to advanced cognitive impairment. Therefore, objective itch-assessment tools that do not rely on patients' reports of itching may be of value for this patient group.

OBJECTIVE

To summarise the characteristics of validated objective itch-assessment tools for patients with advanced cognitive impairment.

METHODS

This scoping review was conducted according to the PRISMA extension for scoping reviews checklist. The PubMed, CINAHL and Cochrane Library databases were searched, via database-specific search strategies, for articles published in English between January 1, 1990 and March 11, 2020. Based on the eligibility criteria, two authors independently screened the articles for inclusion. Thereafter, the lead author performed data extraction and analysis.

RESULTS

Three validated scratch-monitoring using accelerometers and a sound sensor and one validated scratch-mark assessment have been reported. The Actiwatch Plus, ActiTrac® , body-conducted sound sensor and Scoring Atopic Dermatitis index for scratching (SCORAD-scratch) had positive criterion validity outcomes. The Actiwatch Plus, ActiTrac® and body-conducted sound sensor were significantly correlated with scratch behaviour (r = 0.91, p < 0.001; r = 0.71, p = 0.042; r = 0.99, and p-value not shown, respectively). The SCORAD-scratch was significantly correlated with subjective itch-assessment scores (r = 0.78-0.80, p = <0.0001-0.010).

CONCLUSIONS

This scoping review summarises the characteristics of validated objective itch-assessment tools to investigate which of these are applicable to older patients with advanced cognitive impairments. Although there are limitations and further verification is required, the ActiTrac® , Actiwatch Plus and body-conducted sound sensor may be useful for measuring scratch movements and itching.

IMPLICATIONS FOR PRACTICE

Nurses and patients' families may better understand the characteristics and validity of each objective itch-assessment tool and select the optimal tool for patients with advanced cognitive impairment who cannot express their discomfort caused due to itching.

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.