Effect of scratching and friction on human skin in vivo.

OBJECTIVE: To investigate effect of scratching and friction on human skin function and functional differences between scratching and friction. METHOD: Forty healthy volunteers were enrolled. Scratching and friction behavior was modeled by scalpel and sandpaper simulation to forearm for 80 times, respectively. Noninvasive bioengineering devices were used to measure basic skin physiological parameters and exfoliated stratum corneum collected and protein quantified. Parameters were recorded at baseline (BL) and after every 20 times interventions (20, 40, 60, and 80 times). RESULTS: Compared to BL, transepidermal water loss (TEWL) value increased significantly at both scratched and friction sites (P < .001) with a significant higher value for friction (P < .001). There was no significant difference in stratum corneum hydration (SCH) value postscratching (P > .05), while it decreased first and then increased significantly at friction site (P < .001). Roughness values (contract (CONT), variety (VAR), and scaliness (SEsc)) were raised significantly at both sites (P < .001). Net change in CONT and SEsc values of friction was higher than scratched sites (P > .05). There was no significant difference in blood flow after both scratching and friction (P > .05). Quantity of keratinocyte protein from friction sites was statistically higher than scratching after 80 times interventions (P < .05). CONCLUSION: Both noninvasive detections and protein quantification indicated more damage from friction, which may have significance for behavior guidance of patients with pruritus and implication for further investigation.

Decreased expression of IL-27 in moderate-to-severe psoriasis and its anti-inflammation role in imiquimod-induced psoriasis-like mouse model.

BACKGROUND: Psoriasis is a high-incident T-cell-mediated autoimmune disease mainly affecting the skin. Interleukin (IL)-27 is a novel member of the IL-6/IL-12 cytokine family, which plays a versatile role in the differentiation and function of distinct T cell subsets. Previous studies uncovered that IL-27 promoted the onset of psoriasis through enhancing the differentiation of T helper (Th) 1 cells. However, the role of IL-27 in other psoriasis-related Th lineages, especially Th17 cells, remains elusive. OBJECTS: The study aimed to investigate the role of IL-27 in the progression of psoriasis and its underlying mechanisms, particularly its influence on Th1 and Th17. METHODS: IL-27 and IL-27 receptor α (IL-27Rα) expressions in normal and lesional skin were determined by immunohistochemistry and western blot analysis. Serum levels of IL-27 and IL-10 were measured by ELISA. Expression levels of IL-27 and IL-27 receptor (IL-27R) mRNA in the skin tissue and peripheral blood mononuclear cells (PBMC) were assessed by quantitative polymerase chain reaction (PCR) analysis. To explore the function of IL-27 in vivo, we used imiquimod (IMQ)-induced psoriasis mouse model. We treated mice with IL-27 or its antagonist, evaluated disease severity and detected the cytokine secretion from splenic CD4+ T cells by flow cytometric analysis and the expression levels of IL-17 and IFN-γ in serum and skin lesion. RESULTS: The expression levels of IL-27 and IL-27Rα were significantly reduced in the moderate-to-severe psoriatic lesions, along with a consistent decrease in serum IL-27 levels, compared with those of healthy control subjects. Moreover, subcutaneous administration of IL-27 recombinant protein lessened severity of IMQ-induced psoriasis-like cutaneous lesions, whereas IL-27p28 antagonist exaggerated the disease severity. Further analysis revealed that IL-27 significantly repressed IL-17 secretion from CD4+ T lymphocytes. Also administration of IL-27 decreased IL-17A level while IL-27p28 antagonist increased IL-17A level in serum and psoriasis-like lesion in the IMQ-treated mice. CONCLUSION: Our results suggest that IL-27 might predominantly play a protective role in the pathogenesis of psoriasis through abrogating Th17 differentiation. The potential therapeutic benefit of harnessing IL-27 in treating psoriasis awaits future investigation.

Acquired reactive perforating collagenosis: A report of a typical case.

BACKGROUND: Reactive perforating collagenosis (RPC) is a rare form of transepithelial elimination, in which altered collagen is extruded through the epidermis. There are 2 types of RPC, acquired RPC (ARPC) and inherited RPC, while the latter is extremely rare. Here we report on 1 case of ARPC. METHODS: A 73-year-old female was presented with strongly itchy papules over her back and lower limbs for 3 months. She denied the history of oozing or vesiculation. A cutaneous examination showed diffusely distributed multiple well-defined keratotic papules, 4 to 10 mm in diameter, on the bilateral lower limbs and back as well as a few papules on her chest and forearm. Scratching scars were over the resolved lesions while Koebner phenomenon was negative. The patient had a history of type 2 diabetes for 15 years. Laboratory examinations showed elevated blood glucose level. Skin lesion biopsy showed a well-circumscribed area of necrosis filled with a keratotic plug. Parakeratotic cells and lymphocytic infiltration could be seen in the necrosed area. In dermis, sparse fiber bundles were seen perforating the epidermis. These degenerated fiber bundles were notarized as collagen fiber by elastic fiber stain, suggesting a diagnosis of RPC. RESULTS: Then a diagnosis of ARPC was made according to the onset age and the history of diabetes mellitus. She was treated with topical application of corticosteroids twice a day and oral antihistamine once a day along with compound glycyrrhizin tablets 3 times a day. And the blood glucose was controlled in a satisfying range. Two months later, a significant improvement was seen in this patient. CONCLUSION: Since there is no efficient therapy to RPC, moreover, ARPC is considered to be associated with some systemic diseases, the management of the coexisting disease is quite crucial. The patient in this case received a substantial improvement due to the control of blood glucose and application of compound glycyrrhizin tablets.