Kirsty Brown

Effect of olive and sunflower seed oil on the adult skin barrier: implications for neonatal skin care.

Natural oils are advocated and used throughout the world as part of neonatal skin care, but there is an absence of evidence to support this practice. The goal of the current study was to ascertain the effect of olive oil and sunflower seed oil on the biophysical properties of the skin. Nineteen adult volunteers with and without a history of atopic dermatitis were recruited into two randomized forearm‐controlled mechanistic studies. The first cohort applied six drops of olive oil to one forearm twice daily for 5 weeks. The second cohort applied six drops of olive oil to one forearm and six drops of sunflower seed oil to the other twice daily for 4 weeks. The effect of the treatments was evaluated by determining stratum corneum integrity and cohesion, intercorneocyte cohesion, moisturization, skin‐surface pH, and erythema. Topical application of olive oil for 4 weeks caused a significant reduction in stratum corneum integrity and induced mild erythema in volunteers with and without a history of atopic dermatitis. Sunflower seed oil preserved stratum corneum integrity, did not cause erythema, and improved hydration in the same volunteers. In contrast to sunflower seed oil, topical treatment with olive oil significantly damages the skin barrier, and therefore has the potential to promote the development of, and exacerbate existing, atopic dermatitis. The use of olive oil for the treatment of dry skin and infant massage should therefore be discouraged. These findings challenge the unfounded belief that all natural oils are beneficial for the skin and highlight the need for further research.

The effect of tacrolimus compared with betamethasone valerate on the skin barrier in volunteers with quiescent atopic dermatitis.

Atopic dermatitis (AD) is an inflammatory skin disease arising as a result of immune system and skin barrier defects. Topical corticosteroids are safe and effective treatments for AD, when used in short courses. Prolonged use is associated with skin barrier damage. Topical calcineurin inhibitors are alternative immune‐modulating treatments for AD purported to have no negative effects on the skin barrier.

The Effect of an Emollient Containing Urea, Ceramide NP, and Lactate on Skin Barrier Structure and Function in Older People with Dry Skin.

Xerosis affects up to 75% of older people and develops as a result of a skin barrier defect. Emollients are widely used to treat xerosis; however, there is limited understanding of the differences between them and their effects on the skin barrier in older people. This study aimed to compare the effect of a commercially available emollient containing 5% urea, ceramide NP and lactate (test emollient) to an alternative emollient without these additives (control emollient) on the properties of the skin barrier in older people. Two cohorts of 21 volunteers aged >60 years with dry skin were recruited. The first applied the test emollient to one forearm and no treatment to the other for 28 days. The second compared the test emollient to the control emollient observing the same parameters. Effects on the skin barrier were determined by measuring skin barrier function, hydration, skin surface pH and by analysing Fourier transform infrared spectra before and after treatment. A third cohort of 6 young adults was recruited to investigate the effect of a single treatment with the test emollient on the molecular structure of the skin barrier at greater depths by employing the tape-stripping technique. The test emollient hydrated the skin to a significantly greater extent and for a longer period of time compared to the control emollient, an effect associated with a significant elevation of carboxylate groups (a marker of natural moisturizing factor content) within the stratum corneum. Furthermore, the test emollient imparted additional benefits to the structure and function of the skin barrier not exhibited by the control emollient. In conclusion, the test emollient addressed the pathological features of xerotic aged skin, supporting its use as first-line therapy for xerotic skin conditions in this population.

A functional mechanistic study of the effect of emollients on the structure and function of the skin barrier.

Preventing relapses of atopic dermatitis (AD) through the regular use of topical products to repair the skin barrier defect is an emerging concept. It is still unclear if some commonly used emollients exert a positive effect on the skin barrier.

Development of stratum corneum chymotrypsin-like protease activity and natural moisturizing factors from birth to 4 weeks of age compared with adults

From birth, the functional properties of the neonatal epidermal barrier mature whereby the stratum corneum (SC) hydrates and the skin surface acidifies. The identification of a thinner infant SC compared with adults suggests underdeveloped mechanisms underlying differentiation and desquamation.

Comparing the Effect of a Twice-weekly Tacrolimus and Betamethasone Valerate Dose on the Subclinical Epidermal Barrier Defect in Atopic Dermatitis

The proactive use of topical anti-inflammatory (TAI) therapy to address subclinical inflammation is an effective, contemporary clinical strategy for the management of atopic dermatitis (AD). The interaction of a proactive TAI dose with the subclinical epidermal barrier defect in AD is yet to be determined. A randomised, observer-blind, functional mechanistic study in 17 subjects with quiescent AD was performed to compare the effect of a twice-weekly dose of betamethasone valerate (0.1%) cream (BMVc), against tacrolimus (0.1%) ointment (TACo) on the biophysical and biological properties of the epidermal barrier. Application of BMVc preserved epidermal barrier function and stratum corneum (SC) integrity, but significantly elevated skin-surface pH with concomitant loss of SC cohesion. By contrast, TACo improved SC integrity, exerted an overall hydrating action, and significantly reduced caseinolytic and trypsin-like protease activity. The differential effects reported support the proactive use of TACo to promote reparation of the subclinical barrier defect in AD.

Vitamin D and antimicrobial peptide levels in patients with atopic dermatitis and atopic dermatitis complicated by eczema herpeticum: A pilot study

In this study, Vitamin D supplementation results in improved clinical severity of atopic dermatitis and increased skin surface LL-37 levels, analyzed by a novel, non-invasive method. Vitamin D supplementation could be a therapeutic option in AD.