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Papers by Simon Danby

Annals of Allergy Asthma & Immunology, May 1, 2022

OBJECTIVE To critically appraise the evidence for the role of regular moisturiser application in ... more OBJECTIVE To critically appraise the evidence for the role of regular moisturiser application in early life to prevent atopic dermatitis and food allergy. DATA SOURCES Primary peer reviewed literature. STUDY SELECTIONS Original research articles based on systematic reviews, interventional studies, retrospective studies, case control and cohort studies related to the subject matter. RESULTS There is good evidence to show that epicutaneous sensitisation through a defective skin barrier is important in development of atopic dermatitis (AD) and food allergy (FA). This supports moisturiser use in prevention as some of them have been proven to restore skin barrier with clear benefits in AD, while there is some limited evidence that these products may reduce allergic sensitisation. However, moisturisers have varied effects depending on ingredients and formulation, some of which are paradoxical like increasing TEWL and enhancing penetration of substances in the skin. These effects may be responsible for some of the conflicting outcomes of prevention studies, some of which suggest that moisturisers are not useful in prevention of AD and FA, while others show a positive trend. Interestingly, there is some suggestion that moisturisers may increase the risk for allergy development perhaps through these paradoxical effects. CONCLUSION While moisturiser use is beneficial in the management of AD, current evidence suggests that it may be ineffective in prevention of AD and FA. Further studies are needed to determine the effects of moisturisation on allergic sensitisation and inflammation and to investigate if moisturiser type, frequency, duration, and age of application significantly affect the prevention and development of these allergies.

BioMed Research International, Jul 12, 2018

Skin physiology is dynamically changing over the first years of postnatal life; however, ethnic v... more Skin physiology is dynamically changing over the first years of postnatal life; however, ethnic variations are still unclear. The aim of this study was to characterize infant skin barrier function, epidermal structure, and desquamation-related enzymatic activity as compared to that of adult skin in an East Asian population. The skin properties of 52 infants (3-24 months) and 27 adults (20-40 years) were assessed by noninvasive methods at the dorsal forearm and upper inner arm. Transepidermal water loss and skin surface conductance values were higher and more dispersed for infants compared to adults. Infant skin surface pH was slightly lower than adult on the dorsal forearm. The infant SC and viable epidermis were thinner compared to adults with differences that were site-specific. Although the chymotrypsin-like activity for infant skin was comparable to adult level, the caseinolytic specific activity was significantly higher for the infant cohort. These observations indicate a differently controlled pattern of corneocyte desquamation in infants. In conclusion, structural and functional differences exist between infant and adult skin in the East Asian population pointing to dynamic maturation of the epidermal barrier early in life.

Philosophical Transactions of the Royal Society A, May 15, 2017

Atopic dermatitis (AD) is a common chronic skin disease characterized by recurrent skin inflammat... more Atopic dermatitis (AD) is a common chronic skin disease characterized by recurrent skin inflammation and a weak skin barrier, and is known to be a precursor to other allergic diseases such as asthma. AD affects up to 25% of children worldwide and the incidence continues to rise. There is still uncertainty about the optimal treatment strategy in terms of choice of treatment, potency, duration and frequency. This study aims to develop a computational method to design optimal treatment strategies for the clinically recommended 'proactive therapy' for AD. Proactive therapy aims to prevent recurrent flares once the disease has been brought under initial control. Typically, this is done by using

British Journal of Dermatology, Jul 22, 2016

What's already known about this topic?  From birth the acidification and hydration of the infant... more What's already known about this topic?  From birth the acidification and hydration of the infant stratum corneum to adult levels suggests transitory mechanisms underlying differentiation and desquamation. What does this study add?  Superficial chymotrypsin-like protease activity and natural moisturising factors (NMF) increase from birth to 4 weeks of age and differ to adults.  Impaired barrier function at birth is accompanied by elevated protease activity and reduced NMF, highlighting why certain infants are predisposed to epidermal barrier breakdown and the development of atopic dermatitis.

Journal of Dermatological Treatment, Oct 21, 2019

Atopic dermatitis (AD), also known as atopic eczema, is a chronic inflammatory skin condition ass... more Atopic dermatitis (AD), also known as atopic eczema, is a chronic inflammatory skin condition associated with a significant health-related and socioeconomic burden, and is characterized by intense itch, disruption of the skin barrier, and upregulation of type 2-mediated immune responses. The United Kingdom (UK) has a high prevalence of AD, affecting 11-20% of children and 5-10% of adults. Approximately 2% of all cases of childhood AD in the UK are severe. Despite this, most AD treatments are performed at home, with little contact with healthcare providers or services. Here, we discuss the course of AD, treatment practices, and unmet need in the UK. Although the underlying etiology of the disease is still emerging, AD is currently attributed to skin barrier dysfunction and altered inflammatory responses. Management of AD focuses on avoiding triggers, improving skin hydration, managing exacerbating factors, and reducing inflammation through topical and systemic immunosuppressants. However, there is a significant unmet need to improve the overall management of AD and help patients gain control of their disease through safe and effective treatments. Approaches that target individual inflammatory pathways (e.g. dupilumab, anti-interleukin (IL)-4 receptor a) are emerging and likely to provide further therapeutic opportunities for patient benefit.

British Journal of Dermatology, Aug 23, 2016

Background Preventing relapses of atopic dermatitis (AD) through the regular use of topical produ... more Background 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. Objectives To determine the skin barrier effects of emollients commonly prescribed in the UK. Methods Two cohorts of volunteers with quiescent AD undertook observer-blind forearmcontrolled studies. The first (18 volunteers) treated the volar side of one forearm with 2 fingertip units of Doublebase TM gel twice daily for 4 weeks. The second cohort (19 volunteers) undertook the same regimen using Diprobase® cream. Transepidermal water loss (TEWL), stratum corneum integrity and hydration, skin-surface-pH and redness were determined at the test sites before and after treatment. Results Neither Diprobase® cream nor Doublebase TM gel significantly affected the underlying skin barrier function. Both emollients were associated with significantly increased skinsurface-pH immediately after application (by 0.8±0.19 and 1.0±0.18 units respectively), and no erythema. Diprobase® cream artificially and transiently (6 hours) improved permeability barrier function by 2.9-3.1 g/m 2 /h TEWL and increased skin hydration by 6.0-6.2 units. Doublebase TM gel, containing humectants, was associated with a greater (between 10.1 and 13.0 units during the first 6 hours) and more sustained increase in hydration, lasting more than 12 hours following repeated use. Conclusion Diprobase® cream and Doublebase TM gel are not associated with skin barrier harm and appear to be appropriate for AD treatment. Whilst displaying emollient properties, neither formulation displayed an ability to actively improve sustained skin barrier function.

Journal of Investigative Dermatology, 2018

If citing, it is advised that you check and use the publisher's definitive version for pagination... more If citing, it is advised that you check and use the publisher's definitive version for pagination, volume/issue, and date of publication details. And where the final published version is provided on the Research Portal, if citing you are again advised to check the publisher's website for any subsequent corrections.

Biomedical Optics Express, Jun 30, 2023

Crisaborole 2% ointment is a non-steroidal treatment for mild-moderate atopic dermatitis (AD) and... more Crisaborole 2% ointment is a non-steroidal treatment for mild-moderate atopic dermatitis (AD) and may produce fewer adverse effects than topical corticosteroids (TCS). We used PS-OCT to quantify dermal collagen at baseline and after 29 days of treatment with crisaborole and betamethasone valerate (BMV), in 32 subjects. PS-OCT detected a mean increase 1 × 10-6, 95% CI (6.3, 1.37) × 10-6 in dermal birefringence following TCS use (p < 0.0001, ad-hoc, not powered), whereas a change of -4 × 10-6, 95% CI (-32, 24) × 10-6 was detected for crisaborole (p = 0.77, ad-hoc, not powered). These results could suggest a differential effect on dermal collagen between the two compounds. PS-OCT may thus find an important role in safety assessment of novel AD treatment’ and larger trials are warranted.

British Journal of Dermatology

Recently, there has been some evidence of an increased incidence of food allergy in infants regul... more Recently, there has been some evidence of an increased incidence of food allergy in infants regularly applying some types of emollients. Considering that emollient vehicles can modify the delivery of ‘actives’ into the skin, it is important to examine their effects on epicutaneous sensitization to environmental allergens. The aim was to determine the effects of regular emollient use on cutaneous reactions to house dust mite allergen. An observer-blind within-participant multilateral controlled interventional study in 40 adults with confirmed house dust mite allergy was carried out. Participants underwent 4 weeks of treatment with olive oil, coconut oil and a basic emollient cream (no added moisturizers) applied to three different areas of both forearms with a fourth area left as a no-treatment control (NTC). At the end of treatment, skin barrier integrity was assessed by performing transepidermal water loss (TEWL) measurements in conjunction with tape-stripping. At adjacent location...

Frontiers in Virology

BackgroundWashing hands with soap and lukewarm water for 20 s is a fundamental measure advocated ... more BackgroundWashing hands with soap and lukewarm water for 20 s is a fundamental measure advocated especially within the UK to help control the spread of viral disease. However, these practices can induce irritant contact dermatitis, particularly in healthcare professionals (HCPs). HCPs typically manage their condition by replacing soap or alcohol-based hand sanitizers with cleansers containing mild surfactants and/or emollient ingredients [skin-friendly cleansers (SFCs)] to mitigate skin damage and/or using topical emollients after washing for repair. Despite this widespread practice, there is very limited evidence supporting the efficacy of these interventions in the prevention of viral propagation.MethodologyWithin this study a range of viruses comprising human coronavirus (HCoV), herpes simplex virus (HSV)-1, influenza (IVA), adenovirus (Ad), and murine norovirus (MNV) were tested against multiple hand wash products, including SFCs. In vitro analysis using plaque assays and tissue...

Clinical and Experimental Dermatology

SummaryBackgroundEczema (atopic dermatitis; AD) is a very common itchy skin condition affecting 1... more SummaryBackgroundEczema (atopic dermatitis; AD) is a very common itchy skin condition affecting 1 in 5 children and up to 1 in 10 adults worldwide. The skin of eczema sufferers is prone to redness, irritation and dryness because it does not form an effective barrier, i.e. the ability of the skin to stop irritants, allergens and microorganisms getting into the body. Skin barrier dysfunction is a hallmark of AD. The regular and liberal (600 g/week for an adult) use of emollients is recommended for all patients with eczema), even between episodes of itching and redness, to soften and soothe the skin. In England alone, almost 9 million prescriptions for emollient creams were issued in 2018, at a cost of over £50 million. Despite this widespread use, relatively little is known about how commonly prescribed emollient creams affect the skin's barrier, and thus the role of moisturizers in AD development and progression remains unclear. We set out to compare three different types of emol...

Journal of the American Academy of Dermatology, 2020

Objectives: Neighbourhood-level deprivation is associated with hospitalization related to respira... more Objectives: Neighbourhood-level deprivation is associated with hospitalization related to respiratory infections; however, hospitalizations exclude many who seek care with less severe respiratory illnesses. Another major seasonal contributor to respiratory illness-associated healthcare burdens are influenzalike illness (ILI)erelated emergency department (ED) visits. We investigated associations between area-level social and material deprivation and ILI-related ED use. Study design: This is a retrospective ecological study. Methods: We linked ILI-related ED visit data (2004e2014) for Edmonton, Alberta to a Canadian arealevel material and social deprivation index, categorizing deprivation into quintiles. Using a multivariable Poisson model with log population as the offset, we modelled the relationship between visit rates and material and social deprivation adjusting for week and season, age, sex and the interaction between age and sex. Results: We included 67,585 ILI-related ED visits, representing 1075.5 (95% confidence interval (CI) ¼ 1067.4e1083.6) visits per 100,000 person-years. ILI-related visit rates increased as each of material and social deprivation increased; increases were slightly greater for material deprivation. Comparing the most deprived quintile to the least deprived quintile: for material deprivation, ILI-related ED visit rates were two times higher (rate ratio (RR) ¼ 2.00, 95% CI ¼ 1.96e2.05); and, for social deprivation, one-anda-half times higher (RR ¼ 1.47, 95% CI ¼ 1.44e1.51). Conclusions: Higher area-level material and social deprivation were associated with higher ILI-related ED visit rates. These findings can be used to identify areas that may need additional public health and healthcare resources and to improve targeting of prevention strategies. Understanding differentials in healthcare use such as this may be especially relevant to ensuring equity of outcomes for pandemic preparedness planning.

Journal of the Mechanical Behavior of Biomedical Materials, 2021

This is a repository copy of Effect of seasonal change on the biomechanical and physical properti... more This is a repository copy of Effect of seasonal change on the biomechanical and physical properties of the human skin.

Clinical & Experimental Allergy, 2021

BackgroundObservational studies suggest an increased risk of eczema in children living in hard ve... more BackgroundObservational studies suggest an increased risk of eczema in children living in hard versus soft water areas, and there is, therefore, an interest in knowing whether softening water may prevent eczema. We evaluated the feasibility of a parallel‐group assessor‐blinded pilot randomized controlled trial to test whether installing a domestic ion‐exchange water softener before birth in hard water areas reduces the risk of eczema in infants with a family history of atopy.MethodsPregnant women living in hard water areas (>250 mg/L calcium carbonate) in and around London UK, were randomized 1:1 antenatally to either have an ion‐exchange water softener installed in their home or not (ie to continue to receive usual domestic hard water). Infants were assessed at birth and followed up for 6 months. The main end‐points were around feasibility, the primary end‐point being the proportion of eligible families screened who were willing and able to be randomized. Clinical end‐points wer...

Xerosis affects up to 75% of older people and develops as a result of a skin barrier defect. Emol... more 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.

British Journal of Dermatology, 2015

Dermatology and Therapy, 2021

Dermatology and Therapy, 2020

Introduction: The replenishment of skin lipids depleted in the dry skin state is a desirable ther... more Introduction: The replenishment of skin lipids depleted in the dry skin state is a desirable therapeutic target to restore skin moisturization; however, there is limited evidence demonstrating the success of this approach through the use of topical emollients. The purpose of this study was to provide evidence of the benefits of a cream and equivalent lotion containing skin lipids in a multi-vesicular emulsion for the management of dry skin. The hypothesis was that the test cream and test lotion could sustain skin moisturization for longer than Digital Features To view digital features for this article go to

Biomedical optics express, 2018

Measurement of sub-clinical atopic dermatitis (AD) is important for determining how long therapie... more Measurement of sub-clinical atopic dermatitis (AD) is important for determining how long therapies should be continued after clinical clearance of visible AD lesions. An important biomarker of sub-clinical AD is epidermal hypertrophy, the structural measures of which often make optical coherence tomography (OCT) challenging due to the lack of a clearly delineated dermal-epidermal junction in AD patients. Alternatively, angiographic OCT measurements of vascular depth and morphology may represent a robust biomarker for quantifying the severity of clinical and sub-clinical AD. To investigate this, angiographic data sets were acquired from 32 patients with a range of AD severities. Deeper vascular layers within skin were found to correlate with increasing clinical severity. Furthermore, for AD patients exhibiting no clinical symptoms, the superficial plexus depth was found to be significantly deeper than healthy patients at both the elbow (p = 0.04) and knee (p<0.001), suggesting tha...