Prevalence of atopic dermatitis in Leicester: a study of methodology and examination of possible ethnic variation

Preconceptional and perinatal exposure to traffic-related air pollution and eczema in preschool children

BACKGROUND

Evidence linking prenatal exposure to outdoor air pollution with eczema in early childhood is scare, and the role of components of air pollution and exposure timing remains unclear.

OBJECTIVES

We investigated the association between exposure to air pollution during preconceptional and perinatal period and the risk of eczema in preschool children.

METHODS

We conducted a prospective cohort study of 2598 children aged 3-6 years in Changsha, China. The prevalence of eczema was assessed by a standardized health questionnaire administered by the parents. Individual exposures to nitrogen dioxide (NO₂), sulfur dioxide (SO₂) and particulate matter with an aerodynamic diameter≤10μm (PM₁₀) during the 4th-6th and 1st-3rd month before pregnancy, entire pregnancy, and three trimesters were estimated by an inverse distance weighted (IDW) method based on concentrations measured at monitoring stations. Association between childhood eczema and exposure to air pollution was examined by logistic regression models in terms of odds ratio (OR) and 95% confidence interval (CI) for an interquartile range (IQR) increase in exposure.

RESULTS

Life-time prevalence of eczema in preschool children in Changsha was 28.6%. Childhood eczema was associated with traffic-related air pollutant NO₂ during 3 months before pregnancy and entire pregnancy with adjusted ORs=1.19 (95% CI: 1.04-1.37) and 1.21 (95% CI: 1.03-1.42) respectively. The highest risk of eczema was observed for the 1st trimester exposure to NO₂ [OR=1.26 (95% CI: 1.09-1.46)]. However, no association was detected for SO₂ and PM₁₀ exposure during any window. High-level exposure to NO₂ during the whole time period significantly increased the effect of NO₂ in all windows on eczema risk as compared with low-level exposure. Sensitivity analysis indicated that the association between both preconceptional and perinatal exposure to NO₂ and childhood eczema was consistent and robust, and this association was modified by some personal, parental hereditary and indoor environmental factors.

CONCLUSION

Our findings support the hypothesis that early childhood eczema is associated with exposure to traffic-related air pollutant during both preconceptional and perinatal period, especially at a high level of exposure.

Ethnic and socio-economic differences in the prevalence of wheeze, severe wheeze, asthma, eczema and medication usage at 4 years of age: Findings from the Born in Bradford birth cohort

BACKGROUND

Asthma, wheeze and eczema are common in early childhood and cause considerable morbidity. Generally rates of these conditions are higher in high income compared to low income countries. Rates in developed nations are generally higher than in less developed countries. After migration to Western countries, differences in risks of developing these conditions may between migrant and non-migrant may diminish.

METHODS

A convenience sample of 1648 children of White British, Pakistani or Other ethnicity aged between 4 and 5 years were recruited from the main Born in Bradford cohort. Children's parents or guardians were asked to report on a range of potential risk factors and their associations with wheeze, asthma and eczema. Relationships between ethnicity and disease outcomes were examined using logistic regression after adjustment for other relevant risk factors and confounders.

RESULTS

Ethnic differences in doctor diagnosed asthma were evident, with children of other ethnic Origin being less likely and children of Pakistani origin more likely to have a diagnosis than White British or other origin children, although after adjustment for other risk factors this difference only remained significant for the Other Ethnic group. Ethnic differences were not observed in other outcomes including wheeze in the past 12 months, severe wheeze and taking medications for breathing problems.

CONCLUSIONS

In UK born children, traditional risk factors such as gender, family history, socio-economic status and child's medical history may be stronger risk factors than ethnicity or familial migration patterns.

Scoping systematic review of treatments for eczema

Background

Eczema is a very common chronic inflammatory skin condition.

Objectives

To update the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) systematic review of treatments for atopic eczema, published in 2000, and to inform health-care professionals, commissioners and patients about key treatment developments and research gaps.

Data sources

Electronic databases including MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Skin Group Specialised Register, Latin American and Caribbean Health Sciences Literature (LILACS), Allied and Complementary Medicine Database (AMED) and Cumulative Index to Nursing and Allied Health Literature (CINAHL) were searched from the end of 2000 to 31 August 2013. Retrieved articles were used to identify further randomised controlled trials (RCTs).

Review methods

Studies were filtered according to inclusion criteria and agreed by consensus in cases of uncertainty. Abstracts were excluded and non-English-language papers were screened by international colleagues and data were extracted. Only RCTs of treatments for eczema were included, as other forms of evidence are associated with higher risks of bias. Inclusion criteria for studies included availability of data relevant to the therapeutic management of eczema; mention of randomisation; comparison of two or more treatments; and prospective data collection. Participants of all ages were included. Eczema diagnosis was determined by a clinician or according to published diagnostic criteria. The risk of bias was assessed using the Cochrane Collaboration risk-of-bias tool. We used a standardised approach to summarising the data and the assessment of risk of bias and we made a clear distinction between what the studies found and our own interpretation of study findings.

Results

Of 7198 references screened, 287 new trials were identified spanning 92 treatments. Trial reporting was generally poor (randomisation method: 2% high, 36% low, 62% unclear risk of bias; allocation concealment: 3% high, 15% low, 82% unclear risk of bias; blinding of the intervention: 15% high, 28% low, 57% unclear risk of bias). Only 22 (8%) trials were considered to be at low risk of bias for all three criteria. There was reasonable evidence of benefit for the topical medications tacrolimus, pimecrolimus and various corticosteroids (with tacrolimus superior to pimecrolimus and corticosteroids) for both treatment and flare prevention; oral ciclosporin; oral azathioprine; narrow band ultraviolet B (UVB) light; Atopiclair™ and education. There was reasonable evidence to suggest no clinically useful benefit for twice-daily compared with once-daily topical corticosteroids; corticosteroids containing antibiotics for non-infected eczema; probiotics; evening primrose and borage oil; ion-exchange water softeners; protease inhibitor SRD441 (Serentis Ltd); furfuryl palmitate in emollient; cipamfylline cream; andMycobacterium vaccaevaccine. Additional research evidence is needed for emollients, bath additives, antibacterials, specialist clothing and complementary and alternative therapies. There was no RCT evidence for topical corticosteroid dilution, impregnated bandages, soap avoidance, bathing frequency or allergy testing.

Limitations

The large scope of the review coupled with the heterogeneity of outcomes precluded formal meta-analyses. Our conclusions are still limited by a profusion of small, poorly reported studies.

Conclusions

Although the evidence base of RCTs has increased considerably since the last NIHR HTA systematic review, the field is still severely hampered by poor design and reporting problems including failure to register trials and declare primary outcomes, small sample size, short follow-up duration and poor reporting of risk of bias. Key areas for further research identified by the review include the optimum use of emollients, bathing frequency, wash products, allergy testing and antiseptic treatments. Perhaps the greatest benefit identified is the use of twice weekly anti-inflammatory treatment to maintain disease remission. More studies need to be conducted in a primary care setting where most people with eczema are seen in the UK. Future studies need to use the same core set of outcomes that capture patient symptoms, clinical signs, quality of life and the chronic nature of the disease.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

WITHDRAWN: Chinese herbal medicine for atopic eczema

This review has been withdrawn as it has been updated by way of a new protocol and then a review, as the scope of the review has substantially expanded. The citation for the new updated review is as follows: Gu S, Yang AWH, Xue CCL, Li CG, Pang C, Zhang W, Williams HC. Chinese herbal medicine for atopic eczema. Cochrane Database of Systematic Reviews 2013, Issue 9. Art. No.: CD008642. DOI: 10.1002/14651858.CD008642.pub2.

The editorial group responsible for this previously published document have withdrawn it from publication.

Ethnicity and stratum corneum ceramides

BACKGROUND

The barrier function of the skin is dependent on an optimal composition of the stratum corneum lipids, exemplified by the altered lipid profile in patients with atopic eczema (AE). Differences in the global prevalence of AE point to the environment as an important factor in AE. Studies on filaggrin point to a genetic aspect in AE. The influence of environment and genes needs to be explored.

OBJECTIVES

To investigate possible differences in stratum corneum lipids between different healthy ethnicities living in the same environment.

METHODS

Healthy participants without any major skin diseases were enrolled in the study. Twenty-five participants of Asian origin (Asians), 18 of African origin (Africans) and 28 of Danish origin (white-skinned), all students at universities in the Copenhagen area of Denmark, had the ceramide profile of their stratum corneum examined using the cyanoacrylate method and analysed using high-performance thin layer chromatography.

RESULTS

For the ceramide/cholesterol ratio we found statistically significant differences between groups, with Asians having the highest ratio (P < 0·001 as compared with both white-skinned individuals and Africans), white-skinned individuals having intermediate values, and Africans having the lowest values. No statistically significant differences were found between any of the ceramide subgroups.

CONCLUSIONS

We found different ceramide/cholesterol ratios in comparable groups of different ethnicity, pointing to unknown genetic differences.

Size Effects of Polystyrene Nanoparticles on Atopic Dermatitis-like Skin Lesions in NC/NGA Mice

Nano-sized particles are diffusing in the environment with the development of nanotechnology. Polystyrene (PS) nanoparticles are modified industrial products and pharmaceutical agents, however, adverse effects of PS nanoparticles remain to be elucidated. In the present study, we investigated the effects of PS nanoparticles with different sizes on the atopic dermatitis (AD)-like skin lesions in NC/Nga mice assumed to show the skin barrier defect/dysfunction in the presence or absence of mite allergen. Male NC/Nga mice were injected intradermally with three different-sized PS nanoparticles (25, 50, or 100 nm) and/or mite allergen into their right ears. We evaluated clinical scores, ear thickening, histological findings and the local protein expression of inflammatory molecules in the ear and Ig production in serum. PS nanoparticles aggravated AD-like skin lesions related to mite allergen, which was paralleled by the local protein levels of interleukin-4, CCL2/monocyte chemotactic protein-1, CCL3/macrophage inflammatory protein-1 alpha, and CCL4/macrophage inflammatory protein-1 beta. In contrast, PS nanoparticles decreased interferon-γ expression. Furthermore, exposure to PS nanoparticles induced ear swelling and CC-chemokine expression in the absence of allergen. These effects were greater with the smaller PS nanoparticles than with the larger ones regarding overall trend. These results suggest that exposure to PS nanoparticles under skin barrier defect/dysfunction can exacerbate AD-like skin lesions related to mite allergen in a size-dependent manner. The enhancing effects may be accounted for by T helper 2-biased immune responses. Furthermore, PS nanoparticles can evoke skin inflammation via the overexpression of CC-chemokines even in the absence of allergen in atopic subjects.

Epidermal barrier dysfunction in atopic dermatitis. J Invest Dermatol. 2009;129:1892-1908. [PMID: 19494826 DOI: 10.1038/jid.2009.133]

Atopic dermatitis (AD) is a multifactorial, heterogenous disease that arises as a result of the interaction between both environmental and genetic factors. Changes in at least three groups of genes encoding structural proteins, epidermal proteases, and protease inhibitors predispose to a defective epidermal barrier and increase the risk of developing AD. Loss-of-function mutations found within the FLG gene encoding the structural protein, filaggrin, represent the most significant genetic factor predisposing to AD identified to date. Enhanced protease activity and decreased synthesis of the lipid lamellae lead to exacerbated breakdown of the epidermal barrier. Environmental factors, including the use of soap and detergents, exacerbate epidermal barrier breakdown, attributed to the elevation of stratum corneum pH. A sustained increase in pH enhances the activity of degradatory proteases and decreases the activity of the lipid synthesis enzymes. The strong association between both genetic barrier defects and environmental insults to the barrier with AD suggests that epidermal barrier dysfunction is a primary event in the development of this disease. Our understanding of gene-environment interactions should lead to a better use of some topical products, avoidance of others, and the increased use and development of products that can repair the skin barrier.

Titanium Dioxide Nanoparticles Aggravate Atopic Dermatitis-Like Skin Lesions in NC/Nga Mice

Titanium dioxide (TiO2) nanoparticles are produced abundantly and used ubiquitously in various cosmetic products. However, it remains to be determined whether transdermal exposure to TiO2 nanoparticles affects atopic dermatitis (AD), which has been increasing in developed countries. We investigated the effects of different sized TiO2 nanoparticles on AD-like skin lesions induced to mite allergen in NC/Nga mice assumed to show skin barrier dysfunction/defect. Male mice were injected intradermally with TiO2 nanoparticles of three sizes (15, 50, or 100 nm) and/or mite allergen into their right ears. We evaluated clinical scores, ear thickening, histological findings and the protein expression of T helper (Th) 1 and Th2 cytokines in the ear, and the levels of Ig and histamine in serum. TiO2 nanoparticles aggravated AD-like skin lesions related to mite allergen in NC/ Nga mice. The enhancing effects are paralleled by the overproduction of IL-4 in the skin, the levels of total IgE and histamine in serum regarding the overall trend. In contrast, TiO2 nanoparticles decreased the local expression of IFN-γ in the presence of allergen. Additionally, TiO2 nanoparticles alone significantly increased histamine levels in serum and IL-13 expression in the ear. However, different effects related to the size differences of TiO2 nanoparticles were not observed. In conclusion, exposure to TiO2 nanoparticles under skin barrier dysfunction/defect can exacerbate AD symptoms through Th2-biased immune responses. Furthermore, TiO2 nanoparticles can play a significant role in the initiation and/or progression of skin diseases following the barrier dysfunction/defect by histamine release even in the absence of allergen.

Role of foods in irregular aggravation of skin lesions in children with atopic dermatitis

Atopic dermatitis is a common inflammatory skin disease that especially affects children and adolescents. Many environmental factors have been recognized as relevant in aggravating skin lesions of the disease. However, it remains to be determined whether foods play a role in worsening of skin lesions in children with atopic dermatitis. In the present study, we investigated whether foods play a role in irregular aggravation of skin lesions in children with the disease. The study population consisted of 69 patients aged 3-15 years with atopic dermatitis. They were hospitalized and open challenge tests were performed with suspected foods. Photographs of representative skin lesion sites were taken at baseline and before and after the challenge. We determined challenge-positive foods by evaluating the comparable before/after challenge photographs. One to three (average, 1.9) challenge-positive foods were confirmed in 52 (75%) of the 69 patients examined. Predominant offending foods were chocolate, cheese and yogurt. Specific immunoglobulin E values to offending foods were mostly negative. We asked patients to exclude challenge-positive foods from their diets. They were then discharged and followed up for 3 months at our outpatient clinic. Exclusion of the offending foods for 3 months brought about a remarkable improvement in the disease. These results suggest that foods play an important role in irregular aggravation of skin lesions in children with atopic dermatitis.

Interventions to reduce Staphylococcus aureus in the management of atopic eczema

BACKGROUND

Staphylococcus aureus can cause secondary infection in atopic eczema, and it may promote inflammation in eczema that does not look infected. Many antimicrobial products exist for eczema, but it is unclear if they work or if they promote bacterial resistance.

OBJECTIVES

To assess the effects of interventions to reduce Staphylococcus aureus for treating infected or uninfected atopic eczema.

SEARCH STRATEGY

We searched the Cochrane Skin Group Specialised Register (March 2008), the Cochrane Central Register of Controlled Trials (Cochrane Library Issue 1, 2008), MEDLINE (OVID) (from 2002 to March 2008), EMBASE (OVID) (from 2002 to March 2008), Ongoing trials registers (March 2008). References from trials and reviews were searched, pharmaceutical companies were contacted for unpublished trials. There were no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of people with atopic eczema who have been treated with a product intended to reduce S. aureus on the skin.

DATA COLLECTION AND ANALYSIS

Two people independently performed the study selection, data abstraction and quality assessment.

MAIN RESULTS

We included 21 studies (1018 participants) covering 7 treatment categories. Most studies were poorly reported and study differences limited pooling of results. Adverse effects were especially poorly reported, and only one study reported the emergence of resistant bacterial strains following oral antibiotics. Oral antibiotics were not associated with benefit in non-infected (2 trials, 66 participants) or infected eczema (1 trial, 33 participants). We did not find any benefit for antibacterial soaps (1 trial, 50 participants), or antibacterial bath additives (2 trials, 41 participants), or topical antibiotics/antiseptics (4 studies, 95 participants). Adding antibiotics to topical corticosteroids reduced numbers of Staphylococcus aureus in 4 trials (302 participants), but there was no evidence of any clinical benefit in 9 trials involving 677 participants: betamethasone plus neomycin vs clobetasol (MD 1.2; 95% CI 0.25, 2.15), prednicarbate plus antimicrobial vs prednicarbate (RR 0.64; 95% CI 0.25, 1.68), or betamethasone valerate plus gentamicin vs betamethasone (RR 0.31; 95% CI 0.07, 1.35). One trial (30 participants) showed no significant improvement in eczema for those using silver textiles (RR 2.67; 95% CI 0.98, 7.22), despite using 10 times the amount of topical steroids.

AUTHORS' CONCLUSIONS

We failed to find clear evidence of benefit for antimicrobial interventions for people with atopic eczema, despite their widespread use. This does not necessarily mean they do not work because the studies were small and poorly reported. Further large studies with long-term outcomes and clearly defined participants are urgently required.

Topical pimecrolimus for eczema

BACKGROUND

Pimecrolimus was developed as an alternative to topical corticosteroids for treating eczema (atopic dermatitis) but its efficacy and safety compared with existing treatments remains unclear.

OBJECTIVES

To assess the effects of topical pimecrolimus for treating eczema.

SEARCH STRATEGY

We searched the Cochrane Skin Group Specialised Register (to October 2006), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2006), MEDLINE (from 2003 to October 2006), and EMBASE (from 2005 to October 2006). We also contacted researchers and manufacturers in the field.

SELECTION CRITERIA

Randomised controlled trials of 1.0% topical pimecrolimus used twice daily compared against other topical comparators for treating eczema.

DATA COLLECTION AND ANALYSIS

Two authors independently examined each retrieved study for eligibility and extracted data for efficacy, tolerability and safety. A random-effects model was used to estimate the pooled risk ratios (RRs) and 95% confidence intervals (95% CIs).

MAIN RESULTS

We included 31 trials (8019 participants) in the analysis. In short-term (</= 6 weeks) trials, pimecrolimus cream was significantly more effective and well-tolerated than vehicle (cream base, but not containing pimecrolimus). In long-term trials (>/=6 months), pimecrolimus was significantly better than vehicle in preventing flares (9 trials, 3091 participants, RR 1.47, 95% CI 1.32 to 1.64 at six months) and in improving quality of life. Pimecrolimus was significantly less effective than two topical corticosteroids, i.e. 0.1% triamcinolone acetonide for investigators' global assessment (1 trial, 658 participants, RR 0.75, 95% CI 0.67 to 0.83) and 0.1% betamethasone valerate for participants' global assessment (1 trial, 87 participants, RR 0.61, 95% CI 0.45 to 0.81) at three weeks. Pimecrolimus was also associated with significantly more overall withdrawals and skin burning. None of the trials reported on key adverse effects such as thinning of skin. Pimecrolimus was significantly less effective than 0.1% tacrolimus for investigators' global assessment at six weeks (RR 0.58, 95% CI 0.46 to 0.74) and led to more withdrawals due to lack of efficacy (RR 2.37, 95% CI 1.10 to 5.08) based on two trials involving 639 participants, but there was no significant difference in proportions of participants experiencing any adverse events.

AUTHORS' CONCLUSIONS

Topical pimecrolimus is less effective than moderate and potent corticosteroids and 0.1% tacrolimus. The therapeutic role of topical pimecrolimus is uncertain due to the absence of key comparisons with mild corticosteroids.

Psychological and educational interventions for atopic eczema in children

BACKGROUND

Psychological and educational interventions have been used as an adjunct to conventional therapy for children with atopic eczema to enhance the effectiveness of topical therapy. There have been no relevant systematic reviews applicable to children.

OBJECTIVES

To assess the effectiveness of psychological and educational interventions in changing outcomes for children with atopic eczema.

SEARCH STRATEGY

We searched the Cochrane Skin Group Specialised Register (to September 2004), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 2, 2005), MEDLINE (from 1966-2005), EMBASE (from 1980 to week 3, 2005 ), PsycINFO (from 1872 to week 1, 2005). On-line: National Research Register, Meta-register of Controlled Trials, ZETOC alerts, SIGLE (August 2005).

SELECTION CRITERIA

RCTs of psychological or educational interventions, or both, used to manage children with atopic eczema.

DATA COLLECTION AND ANALYSIS

Two authors independently applied eligibility criteria, assessed trial quality and extracted data. A lack of comparable data prevented data synthesis.

MAIN RESULTS

Five RCTs met the inclusion criteria. Some included studies required clearer reporting of trial procedures. Rigorous established outcome measures were not always used. Interventions described in all 5 RCTs were adjuncts to conventional therapy. Four focused on intervention directed towards the parents; data synthesis was not possible. Psychological interventions remain virtually unevaluated by studies of robust design; the only included study examined the effect of relaxation techniques (hypnotherapy and biofeedback) on severity. Three educational studies identified significant improvements in disease severity between intervention groups. A recent German trial evaluated long term outcomes and found significant improvements in both disease severity (3 months to 7 years, p=0.0002, 8 to 12 years, p=0.003, 13 to 18 years, p=0.0001) and parental quality of life (3 months to 7 years, p=0.0001, 8 to 12 years p=0.002), for children with atopic eczema. One study found video-based education more effective in improving severity than direct education and the control (discussion) (p<0.001). The single psychological study found relaxation techniques improved clinical severity as compared to the control at 20 weeks (t=2.13) but this was of borderline significance (p=0.042).

AUTHORS' CONCLUSIONS

A lack of rigorously designed trials (excluding one recent German study) provides only limited evidence of the effectiveness of educational and psychological interventions in helping to manage the condition of children with atopic eczema. Evidence from included studies and also adult studies indicates that different service delivery models (multi-professional eczema school and nurse-led clinics) require further and comparative evaluation to examine their cost-effectiveness and suitability for different health systems.

The treatment of severe atopic dermatitis in childhood with narrowband ultraviolet B phototherapy

BACKGROUND

There is a lack of data regarding the use of narrowband ultraviolet B (NB-UVB) phototherapy in children with atopic dermatitis (AD). Many centres use this mode of treatment for children with AD; however, there have only been two previous studies observing the effect of NB-UVB in children with AD.

AIM

We undertook a retrospective review of children with severe eczema who had undergone NB-UVB consecutively in our department between 1999 and 2005.

METHODS

All children with AD who had undergone NB-UVB consecutively in our department between 1999 and 2005 were identified from the phototherapy database. Their clinical notes were reviewed for information on age, sex, skin type, minimal erythema dose (MED), adjuvant therapy, previous therapy, adverse effects, number of exposures, cumulative dose, response to treatment and length of remission.

RESULTS

In total, 50 children (83%) completed more than 10 exposures of NB-UVB. Complete clearance or minimal residual activity was achieved in 20 children (40%). A good improvement was achieved in a further 10 children (23%), and a moderate improvement in 13 (26%). Children with MEDs > 390 mJ/cm2 were more likely to clear, and this was found to be statistically significant (P = 0.02). Overall, the treatment was well tolerated and the median length of remission was 3 months.

CONCLUSION

NB-UVB is an effective treatment for children with severe AD. Children with MEDs > 390 mJ/cm2 are more likely to clear. Further studies are needed to evaluate the efficacy of NB-UVB and long-term safety in treating children with severe AD.

Self reported skin morbidity and ethnicity: a population-based study in a Western community

Background

Recent studies have shown ethnic differences concerning cardio-vascular disease, diabetes and mental health. Little is known about ethnic differences in skin morbidity. The purpose of this study was to describe possible ethnic differences in self-reported skin morbidity in a Western urban community.

Methods

The design was cross sectional. 40 888 adults in Oslo, Norway, received a postal questionnaire providing information on socio-demographic factors and self-reported health, including items on skin complaints.

Results

18770 individuals answered the questionnaire. In the sample 84% were from Norway. The largest immigrant group was from Western countries (5%) and the Indian Subcontinent (3%). Itch was the most prevalent reported skin symptom (7%), and was significantly more reported by men from East Asia (18%) and Middle East/North Africa (13%). The same observations were seen for reported dry and sore skin. Hair loss was a dominating complaint for men from the Indian Subcontinent and the Middle East/North Africa (23% and 25%) and for women from the same ethnic groups. Women from Sub-Saharan Africa reported significantly more pimples than in the other groups (17%).

Conclusion

The study showed that there were significant differences in self-reported skin complaints among ethnic groups. Issues concerning the cultural value of some skin symptoms should be examined further.

Does visible atopic dermatitis affect quality of life more in women than in men?

BACKGROUND

Studies have suggested that women overreport symptoms in nondermatologic disease. Gender-dependent differences in patients' perception of dermatologic disease are poorly described. The description of possible gender differences in morbidity in a skin disease with comparable prevalence in men and women may therefore provide relevant data.

OBJECTIVE

The goal of this study was to examine gender-dependent differences in the self-reported morbidity of patients with atopic dermatitis (AD).

METHODS

Questionnaires from members of the Atopisk Eksem Forening (Danish Association of Atopic Eczema) aged > or = 15 years were analyzed. Data were gathered regarding age, sex, disease duration and severity, and localization of AD, including the results of the Dermatology Life Quality Index (DLQI), a quality-of-life questionnaire designed for use in adults (ie, patients aged > or = 15 years).

RESULTS

Questionnaires from 112 patients were analyzed. The final study population comprised 88 females and 24 males; mean age was 35.3 years (range, 15-77 years). For women, a significant positive correlation was found between DLQI score and disease severity (P < 0.001) and also between DLQI score and visible regions affected by disease (P = 0.001); these correlations were not observed in men. For the total number of body regions affected, a significant correlation with severity was found for women (P = 0.001) but not for men. No significant differences between men and women were noted for age, disease duration, overall disease severity, or quality of life as assessed using the DLQI.

CONCLUSION

Self-reported morbidity is highly consistent among women with AD, but not so among men. Normally visible areas of AD appear to affect women significantly more than men.

A comparison between criteria for diagnosing atopic eczema in infants

BACKGROUND

Epidemiological studies have shown different estimates of the frequency of atopic eczema (AE) in children. This may be explained by several factors including variations in the definition of AE, study design, age of study group, and the possibility of a changed perception of atopic diseases. The role of IgE sensitization in AE is a matter of debate.

OBJECTIVES

To determine the prevalence and cumulative incidence of AE in a group of unselected infants followed prospectively from birth to 18 months of age using different diagnostic criteria; to evaluate the agreement between criteria; and to describe the association between atopic heredity and postnatal sensitization, respectively, and the development of AE according to the different diagnostic criteria.

METHODS

During a 1-year period a consecutive series of 1095 newborns and their parents were approached at the maternity ward at the Odense University Hospital, Denmark and a cohort of 562 newborns was established. Infants were examined and followed prospectively from birth and at 3, 6, 9, 12 and 18 months of age. AE was diagnosed using four different criteria, the Hanifin and Rajka criteria, the Schultz-Larsen criteria, the Danish Allergy Research Centre (DARC) criteria developed for this study and doctor-diagnosed visible eczema with typical morphology and atopic distribution. Additionally, the U.K. diagnostic criteria based on a questionnaire were used at 1 year of age. Agreement between the four criteria was analysed at each time point and over time, and agreement between the four criteria and the U.K. questionnaire criteria was analysed.

RESULTS

The cumulative 1-year prevalence of AE using the Hanifin and Rajka criteria was 9.8% (95% confidence interval, CI 7-13%), for the Schultz-Larsen criteria it was 7.5% (95% CI 5-10%), for the DARC criteria 8.2% (95% CI 6-11%), for visible eczema 12.2% (95% CI 9-16%) and for the U.K. criteria 7.5% (95% CI 5-10%). The pairwise agreement between criteria showed good agreement, with rates varying between 93% and 97% and kappa scores between 0.6 and 0.8. Agreement analysis of diagnoses between the four criteria demonstrated that cumulative incidences showed better agreement than point prevalence values.

CONCLUSIONS

Agreement between different criteria for diagnosing AE was acceptable, but the mild cases constituted a diagnostic problem, although they were in the minority. Repeated examinations gave better agreement between diagnostic criteria than just one examination. Atopic heredity was less predictive for AE than sensitization to common food and inhalant allergens in early childhood.

Chinese herbal medicine for atopic eczema

BACKGROUND

Traditional Chinese herbal mixtures have been used to treat atopic eczema for many years. Their efficacy has attracted public attention and recently some clinical trials have been undertaken.

OBJECTIVES

To assess the effects of Chinese herbal mixtures in the treatment of atopic eczema.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) ( January 2004), the Cochrane Skin Group Specialised Register (January 2004), MEDLINE (1966 to January 2004), EMBASE (1980 to January 2004), CINHL (1980 to January 2004) and a number of complementary medicine databases. In addition, the cited references of all trials identified and key review articles were searched. Pharmaceutical companies involved in oral traditional Chinese herbs and experts in the field were contacted.

SELECTION CRITERIA

Randomised controlled trials of Chinese herbal mixtures used in the treatment of atopic eczema.

DATA COLLECTION AND ANALYSIS

Two reviewers independently applied eligibility criteria, assessed the quality of the trials and extracted data. Any discrepancies were discussed to achieve consensus.

MAIN RESULTS

Four randomised controlled trials, with eight weeks for each phase, met the inclusion criteria. The trials randomised 159 participants aged from 1 to 60 years. The withdrawal rates ranged from 7.5% to 22.5% and no trial used intention to treat analysis. Three trials were randomised placebo controlled, two-phase cross-over designs assessing the same Chinese herbal mixture, Zemaphyte. In two of these three trials the reduction in erythema and surface damage was greater on Zemaphyte than on placebo, and participants slept better and itched less and expressed a preference for Zemaphyte. The fourth trial was an open-label design comparing Zemaphyte in herbal form with Zemaphyte as a freeze dried preparation. There was a reduction in erythema and surface damage with both formulations, but no comparison between the two formulations was reported. Some adverse effects were reported in all four trials, but none were regarded as serious.

REVIEWERS' CONCLUSIONS

Chinese herbal mixtures may be effective in the treatment of atopic eczema. However, only four small poorly reported RCTs of the same product, Zemaphyte, were found and the results were heterogeneous. Further well-designed, larger scale trials are required, but Zemaphyte is no longer being manufactured.

Natural history of atopic dermatitis and its relationship to serum total immunoglobulin E in a population-based birth cohort study

We investigated the natural history of atopic dermatitis (AD) in a population-based birth cohort and assessed whether children at risk of visible eczema at 5 years of age can be identified from total immunoglobulin E (IgE) levels measured at 8, 12 and 18 months. AD data collected included a whole body examination for visible eczema at 49 months (4 years) and 61 months (5 years) of age and parent completed questionnaire data throughout their early lives. Children were divided into four groups based on their natural history of early AD: persistent (AD at 1, 6, 18, 30 and 42 months, n = 34), intermittent early onset (before 18 months of age, n = 495), intermittent late onset (18-42 months of age, n = 273) and unaffected (n = 429). Visible eczema at 5 years of age was present in 12.2% (117/957) (95% confidence interval [CI] 10.1-14.3%) of the children. Levels of total IgE at 8, 12 and 18 months of age were associated with early onset of AD, but not with AD of later onset. For all four natural history groups, the geometric mean total IgE at 12 months was higher in those who subsequently had visible eczema than those who did not. However, the degree of overlap was such that total IgE at 12 months of age was a poor predictor of eczema at age five. A cutoff point of 78 kU/l had the highest positive predictive value for visible eczema at 5 years of age of 28.6%, with a sensitivity of 12% and specificity of 95%.

Effect of indoor environmental factors on development of atopic symptoms in children followed up to 4 years of age

The increased prevalence of atopic diseases reported in many Western countries is thought to be caused by changes in living conditions. For a long time attention was focused on indoor environmental factors and early feeding patterns, but during recent years other factors have received more attention. An unselected, Swedish, population-based cohort of 904 children were followed from the age of 3 months to 4 years. Questionnaires were sent to the mothers of the children when they were 3 months, 18 months and 4 years of age. A blood sample was taken from a subgroup of the children when they were 4 years old which was analysed for IgE specific antibodies to food and inhalant allergens. The prevalences of asthma, allergic eye-nose reactions, eczema, and food reactions at 4 years of age and a positive blood test were analysed as outcome factors. Features of housing and early feeding patterns were found to have limited effect on the development of allergies in the children. Presence of older siblings resulted in a decreased tendency to produce IgE antibodies. Early exposure to furry animals seemed to prevent the development of asthma. Children who were frequently infected up to 18 months of age showed an increased prevalence of allergic symptoms at 4 years of age. Children of mothers with a higher prevalence of complaints about indoor factors, or who had increased general symptoms or skin or mucous membrane symptoms ran a greater risk of developing various allergic symptoms. However, these children did not have higher levels of IgE antibodies. The reported allergic symptoms in the children may be due to non-immunological reactions, although it is also possible that the mothers may have over-reported such symptoms.

A prospective study of the prevalence and incidence of atopic dermatitis in children aged 0-42 months

BACKGROUND

There is strong evidence that the incidence and prevalence of atopic diseases is increasing. However, estimates of the prevalence of atopic dermatitis (AD) have varied greatly in the U.K. and most parts of the developed world.

OBJECTIVES

The aim of the study was to estimate the prevalence and incidence of AD between the ages of 0 and 42 months in children born in the 1990s in a defined population in the U.K.

DESIGN

We used data from the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC), a large population-based study in the U.K. that enrolled all pregnant mothers who were resident in Avon and had their delivery date falling between 1 April 1991 and 31 December 1992. Since then ALSPAC has collected a wide range of data from the newborns and their parents. Data reported here were collected at 6, 18, 30 and 42 months using parental reports in a postal questionnaire. Of the 14 009 children originally enrolled 8530 provided information on AD in each of the four follow-up questionnaires. We defined AD as a report of rash in at least two of the four questionnaires. Incidence risk was defined as the percentage of new cases of AD between follow-up questionnaires, out of the total number of children whose parents had not reported that they had AD by the time of the previous follow-up.

RESULTS

Period prevalence of 21.0%, 25.6%, 23.2% and 19.9% were observed at ages 0-6, 6-18, 18-30 and 30-42 months, respectively. The corresponding incidence risks were 21.0%, 11.2% and 3.8%, at 0-6, 6-18 and 18-30 months, respectively. There were no gender differences in either the incidence or prevalence of the disease.

CONCLUSIONS

Results from this large, prospective study are consistent with recent reports of increased incidence and prevalence of AD. Health planners can use our estimates of incidence and prevalence to project the number of children likely to suffer from AD during infancy and early childhood, and thus to determine the human and financial resources required.

Protein oxidative damage in the stratum corneum: Evidence for a link between environmental oxidants and the changing prevalence and nature of atopic dermatitis in Japan

BACKGROUND

The incidence of atopic dermatitis (AD) has increased in Japan, along with the number of patients with severe and treatment-resistant AD in urban and industrial areas. We hypothesize that these changes could be due to increased reactive oxygen species (ROS) generated from environmental pollution and solar radiation.

OBJECTIVES

To demonstrate whether direct oxidative protein damage of the stratum corneum of the biopsied skin from AD patients is increased when compared with controls.

PATIENTS AND METHODS

Carbonyl moieties in skin biopsies from 75 patients with AD were assessed using both spectrophotometric and immunohistochemical detection of the formation of dinitrophenylhydrazone (DNP) from dinitrophenylhydrazine (DNPH). These were compared with diseased and normal controls. Lipid peroxidation was also assessed by staining with antibody to 4-hydroxy-2-nonenal (4-HNE), an aldehyde product of oxidized omega-6-fatty acids. In addition, the activity of superoxide dismutase (SOD), an effective scavenger of ROS, was assessed and compared with controls.

RESULTS

The level of protein carbonyl moieties in patients' skin was elevated and correlated directly with the severity of the disease. In contrast, DNP formation was not significantly increased in diseased controls, when compared with healthy volunteers, and no statistical significance was found between the two control groups. SOD activity was increased except for those with extra-severe disease. Positive staining with anti-DNP antibody and anti-4-HNE antibody were found in the most superficial layers of the stratum corneum.

CONCLUSIONS

This study has found an association between AD severity and markers of ROS-associated damage, adding weight to the hypothesis that environmentally generated ROS may induce oxidative protein damage in the stratum corneum, leading to the disruption of barrier function and exacerbation of AD.

The epidemiology of atopic dermatitis

Atopic dermatitis is the most common chronic inflammatory skin disease and is a major cause of morbidity and suffering. This review examines its differing prevalence worldwide, its aetiology, and genetics.

The descriptive epidemiology of house dust mite-specific and total immunoglobin E in England using a nationally representative sample

BACKGROUND

Previous studies have shown that IgE levels vary according to factors such as age, gender and smoking but most studies have been small and none have been based on a nationally representative sample.

OBJECTIVES

To investigate the influence of epidemiological factors on serum total IgE and house dust mite-specific IgE levels.

METHODS

An interviewer-led questionnaire was carried out and blood samples taken from 24 952 people aged 11 and over as part of the 1995 and 1996 Health Surveys for England. Serum total IgE and house dust mite-specific IgE were measured.

RESULTS

Both total and house dust mite-specific IgE were more frequently raised in men and in younger age groups. After adjusting for age and sex, raised total IgE was more common in current smokers and non-white ethnic groups and was not related to social class. The higher levels in non-white ethnic groups was not explained by smoking, urban living or being born outside the UK. Whilst total IgE levels declined in older age groups in non-smokers, among smokers they increased across successive age groups from 50 years onwards. In contrast, following adjustment for age and sex, raised house dust mite IgE was more common in non-manual workers and in some non-white ethnic groups but was not related to smoking.

CONCLUSIONS

This large nationwide study provides further confirmation of differing epidemiological patterns for total serum IgE and allergen-specific sensitization. Indicative ranges for 'usual' values for a wide range of ages among men and women in England are given.

Ethnic variations in self-perceived sensitive skin: epidemiological survey

To examine possible ethnic variations in perception of sensitive skin, an epidemiological survey was performed in the San Francisco area. Approximately 800 telephone interviews were conducted with women from four different ethnic groups (Afro-Americans, Asians, Euro-Americans, Hispanics; approximately 200 women per group). In addition to sensitive facial skin assessments, age and other general skin condition data were collected. 52% of the subjects identified themselves as having sensitive facial skin. There was no statistical difference between the ethnic groups in terms of sensitive skin prevalence. Nevertheless, some differences were noted between ethnic subgroups of sensitive skin. Euro-Americans were characterized by a higher skin reactivity to wind and tended to be less reactive to cosmetics. Afro-Americans presented diminished skin reactivity to most environmental factors and a lower frequency of recurring facial redness. Asians appeared to have greater skin reactivity to spicy food, to sudden changes in temperature and to wind, and tended to suffer from itching more frequently. Hispanics presented a lower incidence of skin reactivity to alcohol. The differences in skin sensitivity between ethnic groups concerned mostly factors of skin reactivity and, to a lesser extent, its symptomatology. But, taken together, we note the similarities in comparing how women of varying ethnic backgrounds perceive the sensitive skin condition.

Atopic eczema and the home environment

BACKGROUND

There is strong evidence to suggest that the prevalence of atopic eczema is increasing in developed countries. Environmental factors have been implicated in the disease.

OBJECTIVES

This descriptive case-control study sheds light on the possible association between atopic eczema in school children and various home environmental factors, and generates hypotheses for further studies.

METHODS

The study uses data on reported atopic eczema symptoms collected via a cross-sectional parental postal survey (n = 1350) in Nottingham, U.K. Estimates of the risk of reported eczema associated with various home environmental factors were calculated by means of odds ratios (OR), along with population attributable risk percentages.

RESULTS

The study showed statistically significant associations between atopic eczema symptoms and dampness in the home [OR 1.40; 95% confidence interval (CI) 1.00-1.97], the use of a radiator to heat the child's bedroom (OR 1.50; 95% CI 1.05-2.16) and the use of synthetic pillows (OR 1.51; 95% CI 1.01-2.28). Frequent vacuuming in the home was associated with a decreased prevalence of atopic eczema (OR 0.74; 95% CI 0.58-0.94). The associations with dampness in the home, synthetic pillows and frequency of vacuuming were not altered significantly after adjustment for age, sex and socio-economic status. Population attributable risk percentages for the use of a radiator and synthetic pillows indicate that although the relative risk estimates for these factors may be small, the population impact of these factors is considerable (26% and 28%, respectively), owing to the high prevalence of exposure to these factors among this group of school children.

CONCLUSIONS

Further research is needed to confirm these associations and additional research is needed to see whether they might be causative. Practical public health advice about the importance of controlling the home environment may then be targeted at families with atopic eczema.

Environmental associations with eczema in early life

BACKGROUND

Although atopic eczema (AE) is a common disease, little is known about its causes.

OBJECTIVES

To investigate the role of dietary and environmental factors associated with the development of AE by the age of 2 years.

METHODS

A cohort of children was recruited before birth from a consecutive series of newly pregnant mothers presenting for antenatal care at three general practices in Ashford, Kent, U.K. Data up to the age of 2 years were available for 624 (97%) of the original cohort. AE was defined using components of the U.K. diagnostic criteria for AE, maternal report of doctor-diagnosed eczema and maternally reported eczema. Exposures of interest were family history of allergic disease, dietary and breastfeeding patterns, family size and exposure to indoor domestic allergens.

RESULTS

The cumulative prevalence of AE using the U.K. diagnostic criteria was 14% (95% confidence interval, CI 11-17%). The prevalence of maternally reported doctor-diagnosed eczema was much higher (31%, 95% CI 27-35%) and almost half (45%) the mothers reported that their child had ever had eczema (95% CI 41-49%). The relationship between parental atopy, parental history of allergic disease and the child's eczema was consistently stronger for the mothers than the fathers. There was a marked increase in the prevalence of eczema with increasing maternal education and in less crowded homes, associations that remained significant after controlling for other factors.

CONCLUSIONS

The associations with environmental factors are consistent with the hypothesis that more crowded houses, increased family size and birth order, which may possibly increase early exposure to infections, may offer protection from subsequent development of eczema.

Epidemiology of atopic dermatitis

Although research into atopic dermatitis (AD) has been dominated by the study of cells and chemical mechanisms over the last 40 years, the last 7 years has witnessed a respectable growth within the field of AD epidemiology. Significant advances include valid disease definitions that can be used in epidemiological studies, global prevalence studies, and studies which quantify the morbidity and economic cost of the disease. These have all helped to argue the case for more research into AD. Epidemiological studies demonstrating that AD is commoner in wealthier families, linkage with small family size, increased prevalence in migrant groups, and the increasing prevalence of the disease all argue strongly towards an important role for the environment in determining disease expression. Future research gaps include evaluation of gene-environment interactions, better studies of the natural history of AD, and better clinical trials that answer questions that are important to physicians and their patients.

The epidemiology and experience of atopic eczema during childhood: a discussion paper on the implications of current knowledge for health care, public health policy and research

Atopic eczema is a chronic skin condition affecting between 5% and 20% of children aged up to 11 years at one time or other. Research suggests that prevalence is increasing and various environmental factors have been implicated in the aetiology. While often seen to be a minor problem, research suggests that it can cause considerable disruption to the lives of children and their carers and involves significant cost for the family and health care systems. The current consensus is that the majority of cases of atopic eczema are most appropriately managed within primary care. However, management of the condition is problematic because diagnosis is often difficult. Consultations tend to focus on the physical aspects of the problems neglecting the psychosocial, while treatment remains mainly palliative and can be as diverse as the condition itself. More appropriate and effective primary care management and support for children with atopic eczema and their carers will only be developed if health professionals become more aware of the social context of the disease and the impact on the lives of those affected. Public health responses focusing on primary prevention are also needed. This paper reviews a diverse literature on the epidemiology of the condition, the way in which it affects the lives of children and their carers and the factors that shape their help seeking decisions. The aim is to contribute to a more substantial knowledge base for public health and primary care developments and to point to areas for future research

The role of twin studies in the genetics of skin diseases

With advances in molecular biology and statistical techniques, gene discovery is moving at a fast pace. Most skin diseases have a complex mode of inheritance and the twin design is the ideal model to dissect the genetic architecture. Use of the twin pairings in a variety of ways for associations and linkage studies can enhance gene discovery. This review covers the advantages and limitations of the twin method.

The natural history of childhood eczema: observations from the British 1958 birth cohort study

The National Child Development Study (NCDS) is a birth cohort study whose longitudinal design makes it suitable for examining the natural history of common diseases in childhood such as atopic eczema. We have analysed the age of onset and clearance rates for examined and/or reported eczema in 6877 children born during the period 3-9 March 1958 for whom linked data were available at birth and at the ages of 7, 11, 16 and 23 years. Of the 870 cases with examined or reported eczema by the age of 16 years, 66% had age of onset by the age of 7 years. Of the 571 children with reported or examined eczema by the age of 7 years, the proportion of children who were clear in terms of examined eczema or reported eczema in the last year at ages 11 and 16 years was 65% and 74%, respectively. These 'apparent' or short-term clearance rates fell to 53% and 65%, respectively, after allowance for subsequent recurrences in adolescence and early adulthood. Age of onset of community-ascertained cases of atopic eczema may be later than that reported in hospital-based studies. The long-term prognosis of childhood eczema may be worse than some previous studies have suggested, especially when subsequent recurrences are taken into account.

Epidemiology of allergic diseases

The escalation of allergic diseases (hay fever, asthma, atopic eczema) over recent decades has been linked to an increase in environmental pollutants. The prevalence of hay fever is associated with genetic predisposition, and some reports show an association with urban areas, socioeconomic status, and combined high allergen and automobile exhaust exposure. In asthma, there is also some evidence for geographical variations in prevalence; exercise challenge tests prove positive more often in urban areas than in rural areas. Although genetic predisposition is the strongest single risk factor for atopic eczema, air pollutants may aggravate the condition by acting as unspecific irritants and immunomodulators, leading to increased immunoglobulin E expression. In a study of 678 pre-school children, the influence of maternal smoking habits on individual measures of atopy revealed a positive association between smoking during pregnancy/lactation, and a positive history of atopic eczema. An East-West German comparative study examining different types and levels of air pollution, i.e. sulphurous (industrial; East) and oxidising (urban; West), showed that the prevalence of atopic eczema was greatest in East Germany. When various direct and indirect parameters of air pollution exposure were measured, the greatest association with atopic eczema was found with NOx exposure (indoor use of gas without a cooker hood), and close proximity to roads with heavy traffic. The increased prevalence of atopic eczema cannot be explained by changes in study methodology over time, or conventional risk factors alone; environmental risk factors may be an important contributing factor.

Atopic dermatitis: an update

This review focuses on recent literature regarding the following clinical features of atopic dermatitis (AD); diagnostic criteria, epidemiology and genetics, provocative factors, predictors of disease development and markers of disease severity, therapy, and prognosis. For example, the frequency of AD appears to be increasing, perhaps in response to provocative factors such as food allergens and house dust mites. Determination of reliable markers for disease development may identify susceptible newborns and facilitate avoidance of relevant triggers. Immunomodulating therapy holds promise in the treatment of refractory AD, and new investigation has led to refinements in conventional modalities such as antihistamines and phototherapy.