Conventional sunscreen application does not lead to sufficient body coverage.

OBJECTIVE: This study aimed to assess sunscreen application habits and relative body coverage after single whole body application. METHODS: Fifty-two healthy volunteers were asked to use the test product once, following their usual sunscreen application routine. Standardized UV photographs, which were evaluated by Image Analysis, were conducted before and immediately after product application to evaluate relative body coverage. In addition to these procedures, the volunteers completed an online self-assessment questionnaire to assess sunscreen usage habits. RESULTS: After product application, the front side showed significantly less non-covered skin (4.35%) than the backside (17.27%) (P = 0.0000). Females showed overall significantly less non-covered skin (8.98%) than males (13.16%) (P = 0.0381). On the backside, females showed significantly less non-covered skin (13.57%) (P = 0.0045) than males (21.94%), while on the front side, this difference between females (4.14%) and males (4.53%) was not significant. CONCLUSION: In most cases, the usual sunscreen application routine does not provide complete body coverage even though an extra light sunscreen with good absorption properties was used. On average, 11% of the body surface was not covered by sunscreen at all. Therefore, appropriate consumer education is required to improve sunscreen application and to warrant effective sun protection.

Novel TRPM8 agonist cooling compound against chronic itch: results from a randomized, double-blind, controlled, pilot study in dry skin.

BACKGROUND: Patients suffering from chronic pruritus (CP) due to dry skin with are often applying emollients containing menthol. However, topical menthol may be irritating and of weak potency in severe pruritus. Two TRPM8 agonists, (1R,2S,5R)-N-(2-(2-pyridinyl)ethyl)-2-ispropyl-5-methylcyclohexancarboxamide and menthoxypropanediol, combined as cooling compound (CC) have shown stronger activation of TRPM8 than menthol. OBJECTIVES: Objective of this study was to evaluate the efficacy and safety of CC in alleviating pruritus in patients with dry itchy skin. METHODS: In this vehicle-controlled, double-blind, randomized (1 : 1) study, 70 dry skin patients with pruritus intensity measured by Numerical Rating Scale (NRS) ≥3, were treated twice daily over 4 weeks, either with a lotion containing CC or with its vehicle. RESULTS: At treatment end, pruritus, assessed by a global score, improved significantly more in the CC than in the vehicle group (79.2% vs. 47.1%; P < 0.05; primary endpoint). Also assessed by verbal rating scale (VRS) and percentual improvement, pruritus decreased significantly more in the CC group (P = 0.007/P = 0.015) compared to vehicle arm after treatment. Up to 84% of CC-treated patients reported a significant, sometimes too strong, long-lasting cooling effect. The health-related quality of life improved significantly more in the CC group (P = 0.023). Skin roughness, dryness and hydration improved significantly in both groups without significant differences in-between them. There were no severe adverse events reported. CONCLUSIONS: Treatment of dry and pruritic skin with a lotion containing the TRPM8 agonist combination ameliorates severe pruritus and represents a possible novel treatment for the burdensome symptom. The most suitable treatment concentration needs still to be identified. ClinicalTrials.gov: NCT00669708.

Effective treatment for sensitive skin: 4-t-butylcyclohexanol and licochalcone A.

BACKGROUND: More than 50% of adults report to suffer from sensitive skin. This common condition is characterized by subjective sensations such as prickling, burning, skin tightness or pruritus, and is often accompanied by objective symptoms like inflammation and erythema. OBJECTIVE: The objective of this study was to develop an active ingredient concept for the treatment of sensitive skin. We tested compounds regarding their potential to (i) decrease the release of proinflammatory mediators, which among others induce erythema and (ii) counteract the hyperresponsiveness of nerve fibres and, thus, exert effects on cutaneous neurosensory dysfunction. METHODS: 4-t-butylcyclohexanol, licochalcone A and acetyl dipeptide-1 cetyl ester were analysed in vitro regarding their potential to (i) decrease the release of PGE2 and activation of NFκB and to (ii) inhibit TRPV1 activation or the release of neuronal CGRP. To assess subjective and objective symptoms of skin sensitivity in vivo, two controlled, single-blind, randomized studies were conducted with 4-t-butylcyclohexanol and the combination with licochalcone A. RESULTS: In vitro, 4-t-butylcyclohexanol significantly reduced TRPV1 activation, while acetyl dipeptide-1 cetyl ester had no effect on receptor activation. Licochalcone A significantly decreased NFκB signalling and PGE2 secretion, at lower concentrations than acetyl dipeptide-1 cetyl ester. A formulation containing 4-t-butylcyclohexanol showed a significant immediate anti-stinging/anti-burning effect in vivo, and a cream base containing a combination of 4-t-butylcyclohexanol and a licochalcone A-rich licorice extract reduced shaving-induced erythema. CONCLUSION: In vitro and in vivo data indicate that the combination of the TRPV1 antagonist 4-t-butylcyclohexanol and the potent anti-inflammatory licochalcone A provide an effective active ingredient concept for the treatment of sensitive skin, as the topical application resulted in an immediate relief from symptoms such as erythema and stinging.

A randomized, investigator-blinded efficacy assessment study of stand-alone emollient use in mild to moderately severe atopic dermatitis flares.

BACKGROUND: Whereas emollients are integral to the long-term management of atopic dermatitis (AD), the evidence for their efficacy in disease flares is limited. OBJECTIVE: We aimed to investigate the stand-alone efficacy of an emollient formulation with regard to improvement of the clinical symptoms, skin barrier function and reduction of pathogenic bacterial colonization in acute stage of AD. MATERIALS AND METHODS: Twenty AD volunteers aged 12-65 years with symmetric, mild to moderately severe inflammatory lesions on the forearms/arms were recruited for the study. At inclusion, the forearms/arms of each volunteer were randomized to receive for 1 week either an o/w formulation containing licochalcone A (Glycyrrhiza Inflata root extract), decanediol, menthoxypropanediol and ω-6-fatty acids (emollient arm) or 1% hydrocortisone (HC arm); after 1 week, the application of the emollient and HC were discontinued and the volunteers applied a w/o emollient containing licochalcone A and ω-6-fatty acids on both arms for further 3 weeks. The outcomes included reduction of the clinical and itch severity, decrease in S.aureus colonization, improvement of the barrier function, skin hydration and skin tolerability assessed after 1 week (D7) and after 4 weeks (D28) respectively. RESULTS: In both arms, there was a significant decrease in the severity score, itch intensity, erythema and TEWL on D7 and D28 compared to baseline. In addition, emollient use resulted in pronounced decrease in S.aureus colonization and significant increase of skin hydration on D7. The comparison of the outcomes, based on percentage change from baseline, showed no significant differences between the emollient and HC arm at any time point. CONCLUSIONS: The results of the study indicate that the 1-week stand-alone application of an emollient, tailored to target inflammation, pruritus, compromised barrier function and pathogenic bacterial colonization may offer benefit for the improvement of mild to moderately severe localized flares of AD.

A double-blind, randomized, vehicle-controlled efficacy assessment study of a skin care formulation for improvement of mild to moderately severe acne.

BACKGROUND: Inflammation, increased sebum production and P. acnes colonization are key factors in acne pathogenesis. Cosmetic formulations based on a combination of active compounds with in vitro proven anti-inflammatory, sebum regulating and P. acnes reducing properties may therefore contribute to improve the clinical signs and associated burden of disease. OBJECTIVE: To provide in vivo proof-of-concept, we performed a 9-week, double-blind, randomized, vehicle-controlled study to assess the stand-alone efficacy of a skin care formulation containing licochalcone A, l-carnitine and 1,2-decanediol in volunteers with mild to moderately severe acne (10-25 inflammatory lesions) involving the face. MATERIALS AND METHODS: After enrolment followed by a 1-week standardization of the cleansing procedure, 60 volunteers aged 14-40 years (40 women and 20 men, mean age 22.4 years) were randomized into two groups of 30 volunteers each, to apply either the active formulation or the vehicle twice daily on the face for 8 weeks. Reduction in the lesion count, P. acnes and sebum levels, stratum corneum hydration, Dermatology Life Quality Index (DLQI) and skin tolerability, assessed after 4 and 8 weeks were defined as outcomes. RESULTS: Compared to baseline, the active formulation group showed at the end of the study a reduction in the mean total lesions count and papular lesions, significant reduction in the pustules (P < 0.05) and sebum levels (P < 0.01), marked reduction in P. acnes and improvement of DLQI. No significant changes in the respective parameters were found in the vehicle group. At the end of the study, greater reduction in the total lesion count, papules and pustules, P. acnes colonization, sebum production and more pronounced improvement of life quality in the active formulation group compared to the vehicle were found. CONCLUSIONS: Our results provide evidence for improved outcomes in result of the application of the active formulation compared to the vehicle from both physician's and patient's perspective.

Abnormal differentiation of epidermis in transgenic mice constitutively expressing cyclooxygenase-2 in skin.

In prostanoid biosynthesis, the first two steps are catalyzed by cyclooxygenases (COX). In mice and humans, deregulated expression of COX-2, but not of COX-1, is characteristic of epithelial tumors, including squamous cell carcinomas of skin. To explore the function of COX-2 in epidermis, a keratin 5 promoter was used to direct COX-2 expression to the basal cells of interfollicular epidermis and the pilosebaceous appendage of transgenic mouse skin. COX-2 overexpression in the expected locations, resulting in increased prostaglandin levels in epidermis and plasma, correlated with a pronounced skin phenotype. Heterozygous transgenic mice exhibited a reduced hair follicle density. Moreover, postnatally hair follicle morphogenesis and thinning of interfollicular dorsal epidermis were delayed. Adult transgenics showed a body-site-dependent sparse coat of greasy hair, the latter caused by sebaceous gland hyperplasia and increased epicutaneous sebum levels. In tail skin, hyperplasia of scale epidermis reflecting an increased number of viable and cornified cell layers was observed. Hyperplasia was a result of a disturbed program of epidermal differentiation rather than an increased proliferation rate, as reflected by the strong suppression of keratin 10, involucrin, and loricrin expression in suprabasal cells. Further pathological signs were loss of cell polarity, mainly of basal keratinocytes, epidermal invaginations into the dermis, and formation of horn perls. Invaginating hyperplastic lobes were surrounded by CD31-positive vessels. These results demonstrate a causal relationship between transgenic COX-2 expression in basal keratinocytes and epidermal hyperplasia as well as dysplastic features at discrete body sites.

Localization of prostaglandin-H synthase-1 and -2 in mouse skin: implications for cutaneous function.

Prostaglandin-H synthase (PGHS)-1 and -2 expression in mouse skin and in keratinocytes in culture was determined using immunohistochemistry and Western blot analysis. In normal skin PGHS-1 immunoreactivity was found in individual keratinocytes present in the interfollicular epidermis and the upper part of the hair follicle. PGHS-2 immunostaining was detected in very few individual basal cells of the interfollicular epidermis and of the hair follicle. Upon induction by TPA of an inflammatory epidermal hyperplasia (regenerative hyperplasia) the number of PGHS-2-expressing keratinocytes scattered throughout the basal but not the suprabasal compartment of the interfollicular epidermis was found to be increased while PGHS-1 expression remained unchanged. PGHS-2 immunoreactivity in paraffin sections from TPA-treated skin showed a nuclear in some and a perinuclear and cytoplasmic localization in other keratinocytes. This different distribution may correlate with the proliferative state, since immunofluorescence analysis of mouse keratinocytes in culture demonstrated a predominant perinuclear and cytoplasmic PGHS-2 localization in cycling keratinocytes but a prevalent staining of the nucleus and the nuclear membrane in noncycling cells. Stimulation of proliferation of murine primary keratinocytes by serum resulted in an increased PGHS-2 expression, whereas induction of terminal differentiation by Ca2+ caused a down-regulation of PGHS-2 protein. Only minor changes in PGHS-1 expression were seen. Our data suggest that expression of PGHS-2 in mouse skin epidermis is related to epithelial regeneration.