Filaggrin haploinsufficiency is highly penetrant and is associated with increased severity of eczema: further delineation of the skin phenotype in a prospective epidemiological study of 792 school children

Background Null mutations within the filaggrin gene (FLG) cause ichthyosis vulgaris and are associated with atopic eczema. However, the dermatological features of filaggrin haploinsufficiency have not been clearly defined. Objectives This study investigated the genotype–phenotype association between detailed skin phenotype and FLG genotype data in a population‐based cohort of children. Methods Children (n = 792) aged 7–9 years were examined by a dermatologist. Features of ichthyosis vulgaris, atopic eczema and xerosis were recorded and eczema severity graded using the Three Item Severity score. Each child was genotyped for the six most prevalent FLG null mutations (R501X, 2282del4, R2447X, S3247X, 3702delG, 3673delC). Fisher’s exact test was used to compare genotype frequencies in phenotype groups; logistic regression analysis was used to estimate odds ratios and penetrance of the FLG null genotype and a permutation test performed to investigate eczema severity in different genotype groups. Results Ten children in this cohort had ichthyosis vulgaris, of whom five had mild–moderate eczema. The penetrance of FLG null mutations with respect to flexural eczema was 55·6% in individuals with two mutations, 16·3% in individuals with one mutation and 14·2% in wild‐type individuals. Summating skin features known to be associated with FLG null mutations (ichthyosis, keratosis pilaris, palmar hyperlinearity and flexural eczema) showed a penetrance of 100% in children with two FLG mutations, 87·8% in children with one FLG mutation and 46·5% in wild‐type individuals (P < 0·0001, Fisher exact test). FLG null mutations were associated with more severe eczema (P = 0·0042) but the mean difference was only 1–2 points in severity score. Three distinct patterns of palmar hyperlinearity were observed and these are reported for the first time. Conclusions Filaggrin haploinsufficiency appears to be highly penetrant when all relevant skin features are included in the analysis. FLG null mutations are associated with more severe eczema, but the effect size is small in a population setting.     

Filaggrin loss-of-function mutations are associated with early-onset eczema, eczema severity and transepidermal water loss at 3 months of age

Background Filaggrin loss‐of‐function (FLG) mutations are associated with eczema and skin barrier impairment, but it is unclear whether skin barrier impairment precedes phenotypic eczema in FLG mutation carriers. Objectives To study the association between FLG mutations, skin barrier impairment and clinical eczema at 3 months of age. Methods A total of 88 infants were examined for eczema. Disease severity was determined by the SCORAD eczema severity score. Transepidermal water loss (TEWL) was measured on unaffected forearm skin. Venous blood samples were screened for the four most common FLG mutations found in the U.K. white population (R501X, 2282del4, R2447X and S3247X). Median SCORAD and TEWL measurements in children with and without eczema and FLG mutations were compared. Results Thirty‐three per cent (29/88) of children had clinical eczema. Median SCORAD was 10·6 (range 3·5–31·0). TEWL (g m^?2 h^?1) was higher in children with eczema compared with unaffected infants (median TEWL 14·24 vs. 11·24, P < 0·001). Higher TEWL was associated with more severe disease (r = 0·59, P < 0·001, median TEWL, SCORAD < 15, 13·1 vs. 29·6, SCORAD ≥ 15, P = 0·029). Clinically dry skin was associated with higher TEWL, even in the absence of eczema (median TEWL 17·55 vs. 11·08, P = 0·008). Seventeen per cent (15/88) of children carried at least one FLG mutation. FLG mutation carriers were significantly more likely to have clinically dry skin, even in the absence of eczema [odds ratio (OR) 8·50, 95% confidence interval (CI) 1·09–66·58, P = 0·042]. FLG mutation carriers were also more likely to have eczema by 3 months of age (OR 4·26, 95% CI 1·34–13·57, P = 0·014). FLG mutations were significantly associated with higher median TEWL (all children, FLG‘yes’ 21·59 vs. FLG‘no’ 11·24, P < 0·001), even without clinical eczema (FLG‘yes’ 15·99 vs. FLG‘no’ 10·82, P = 0·01). Conclusions By the age of 3 months, FLG mutations are associated with an eczema phenotype, dry skin and TEWL. The observation that TEWL is elevated in unaffected FLG mutation carriers suggests that skin barrier impairment precedes clinical eczema.     

Emollients and topical glucocorticoids in adolescents with eczema

Eczema, also called atopic eczema, is a common skin disease among children. When you have eczema you usually have dry skin often with itchy rashes. The disease affects about 10‐30 % of all children worldwide. In Sweden, 20% of all children have had or have eczema before the age of 5 years. The disease is less common with age and affects 2‐10 % of all adults. Eczema should be treated with emollients (moisturisers) for the dry skin and cortisone cream on the itchy rash. The knowledge about adolescents with eczema is sparse. This study from Sweden, aimed to find out how adolescents with eczema treat themselves with emollient and cortisone cream, if boys and girls treat themselves differently, if the severity of eczema affects treatment behavior and how much cortisone cream they had dispensed from the pharmacy during the last year. The author used data from 16‐year‐old adolescents who answered questions about eczema and its treatment and who attended a clinical examination. The main finding shows that almost all adolescents used emollients, but only half used cortisone cream, and there were no differences between how boys and girls treated themselves. Symptoms of more severe eczema did not increase the likelihood of using cortisone. Only one out of four with moderate to very severe eczema had a potent cortisone cream dispensed from the pharmacy the preceding year. The authors therefore concluded that many adolescents with eczema are undertreated or completely untreated.     

Eczema among adults: prevalence, risk factors and relation to airway diseases. Results from a large-scale population survey in Sweden

Background In contrast to asthma and rhinitis, few studies among adults investigating the prevalence and risk factors of eczema have been published. Objectives To investigate the prevalence and risk factors of eczema among adults in West Sweden. A further aim was to study the associations between asthma, rhinitis and eczema. Methods A questionnaire on respiratory health was mailed in 2008 to 30 000 randomly selected subjects in West Sweden aged 16–75 years; 62% responded. The questionnaire included questions about eczema, respiratory symptoms and diseases and their possible determinants. A subgroup of 669 subjects underwent skin prick testing against common airborne allergens. Results ‘Eczema ever’ was reported by 40·7% and ‘current eczema’ by 11·5%. Both conditions were significantly more common among women. The prevalence decreased with increasing age. The coexistence of both asthma and rhinitis with eczema was common. The main risk factors were family history of allergy and asthma. The dominant environmental risk factor was occupational exposure to gas, dust or fumes. Smoking increased the risk. Eczema was associated with urbanization, while growing up on a farm was associated with a decreased risk. Added one by one to the multivariate model, asthma, allergic rhinitis and any positive skin prick test were associated with eczema. Conclusions Eczema among adults is a common disease with more women than men having and having had eczema. Eczema is associated with other atopic diseases and with airway symptoms. Hereditary factors and exposure to gas, dust and fumes are associated with eczema.     

Filaggrin null mutations increase the risk and persistence of hand eczema in subjects with atopic dermatitis: results from a general population study

Summary Background Hand eczema is prevalent in the general population. It remains unclear whether or not filaggrin gene (FLG) null mutations increase the overall risk of hand eczema or only increase the risk of hand eczema in subjects with atopic dermatitis. Objectives To investigate the association between FLG null mutations and hand eczema. Methods A random sample of 3335 adults from the general population in Denmark was patch tested, FLG genotyped for R501X and 2282del4 null mutations and questioned about hand eczema. Results Participants with combined presence of atopic dermatitis and FLG null mutation status had a significantly higher prevalence of hand eczema, an earlier onset of hand eczema and a higher persistence of hand eczema compared with subjects with normal FLG status and absence of atopic dermatitis. Logistic regression analyses revealed positive associations between hand eczema within the past 12 months and FLG null mutation status in participants with a history of atopic dermatitis [odds ratio (OR) 2·98; 95% confidence interval (CI) 1·27–7·01], but not in subjects without atopic dermatitis (OR 0·82; 95% CI 0·41–1·67). Conclusions FLG null mutations were significantly associated with hand eczema (< 12 months) in subjects with atopic dermatitis. Combined atopic dermatitis and filaggrin null mutation status was strongly associated with early onset of hand eczema and hand eczema persistence.     

Wide spectrum of filaggrin-null mutations in atopic dermatitis highlights differences between Singaporean Chinese and European populations

Background  Null mutations in the filaggrin gene (FLG) cause ichthyosis vulgaris (IV) and predispose to atopic dermatitis (AD). Cohort studies in Europe and Japan have reported an FLG mutation carrier frequency of between 14% and 56%, but the prevalent European FLG mutations are rare or absent in Chinese patients with IV and AD. Objectives  To investigate further the spectrum of FLG‐null mutations in Chinese patients and to compare it with that in other populations. Methods  We conducted comprehensive FLG genetic analysis in a discovery cohort of 92 Singaporean Chinese individuals with IV and/or moderate‐to‐severe AD. All detected FLG mutations were then screened in a cohort of 425 patients with AD and 440 normal controls. Results  In total, 22 FLG‐null mutations, of which 14 are novel, were identified in this study; the combined null FLG genotype of 17 mutations detected in cases and controls showed strong association with AD [Fisher’s exact test; P = 5·3 × 10^?9; odds ratio (OR) 3·3], palmar hyperlinearity (Fisher’s exact test; P = 9·0 × 10^?15; OR 5·8), keratosis pilaris (Fisher’s exact test; P = 0·001; OR 4·7) and with increased severity of AD (permutation test; P = 0·0063). Conclusions  This study emphasizes the wider genetic landscape of FLG‐null mutations in Asia that is slowly emerging.     

Clinical features of atopic dermatitis at two years of age: a prospective, population-based case-control study

While atopic dermatitis (AD) usually presents early in life, few prospective studies focus on young children with AD. The objective of this study was to characterize, phenotypically and prospectively, young children with AD. From a community birth cohort of 2,256 children, consecutive children with AD (n = 221) were followed to 2 years of age, when they were re-examined and screened for atopic sensitization (skin-prick test to foods; Phadiatop). Ninety-nine controls were also examined. AD debuted during the first year in 88% of cases. At the 2-year examination, when the children had already undergone topical treatment, 157/221 (71%) had ongoing eczema ranging among mild (45%), moderate (53%) and severe (2%). Airway problems indicating asthma had occurred in 9% of cases and 6% of controls (not significant), and allergic rhinoconjunctivitis in 5% and 0%, respectively (p<0.05). The skin-prick test to common food allergens was positive in 27% of cases and Phadiatop was positive in 15%. In 67% both tests were negative. Eczema severity did not differ between sensitized and non-sensitized children. Positive Phadiatop was more common in boys than in girls with ongoing AD (22% vs 3%, p<0.01), and more boys than girls had ongoing AD (82% vs 59%, p<0.001); otherwise, no differences attributable to gender were found.     

Impact of atopic dermatitis and loss‐of‐function mutations in the filaggrin gene on the development of occupational irritant contact dermatitis

Background Atopic dermatitis (AD) and loss‐of‐function mutations in the filaggrin gene (FLG) are both associated with chronic irritant contact dermatitis (ICD). As FLG mutations also are a major risk factor for AD, it is not clear whether FLG mutations are an independent risk factor for ICD or whether the risk is mediated by AD. Objectives To investigate the relative contribution and interaction of FLG mutations and AD in German patients with occupational ICD and controls (vocational school apprentices). Methods A total of 634 patients and 393 controls were genotyped for R501X, 2282del4, R2447X and S3247X. Current or past flexural eczema was used as an indicator of AD. Results FLG mutations were found in 15·9% of the patients with ICD and 8·3% of the controls, with a crude odds ratio (OR) of 2·09 [95% confidence interval (CI) 1·33–3·28] for the combined genotype. The adjusted OR for FLG mutations, corrected for AD, was 1·62 (95% CI 1·01–2·58). Subjects with AD were at approximately three times higher risk of developing ICD than controls (OR 2·89; 95% CI 2·09–3·99). There was no evidence of an interaction between these two risk factors. Conclusions Our results indicate that both FLG mutations and AD increase the risk of ICD. Individuals with concurrent FLG mutations and AD are at the highest risk of developing ICD.     

Filaggrin mutations are associated with recurrent skin infection in Singaporean Chinese patients with atopic dermatitis

Background Loss‐of‐function (null) mutations within the filaggrin (FLG) gene are a strong risk factor for atopic dermatitis (AD). We hypothesized that the absence or reduction of the filaggrin protein could compromise skin barrier and increase patients’ susceptibility to recurrent skin infection. Objectives To investigate the association between FLG‐null mutations and the risk of recurrent skin infection among a series of patients with AD in Singapore. Methods This study included 228 Singaporean Chinese patients with AD with at least 1 year of follow‐up at the time of recruitment between January 2008 and December 2009 at the National Skin Centre in Singapore. Each patient had their medical records reviewed for history of skin infection in the preceding year and was genotyped for 22 FLG‐null mutations. Results Compared with those without the FLG‐null mutations, patients with AD who had FLG mutation(s) had approximately a seven times increased risk of more than four episodes of skin infection requiring antibiotics in the past year (odds ratio 6·74; 95% confidence interval 2·29–19·79). This risk was much greater in those with mild or moderate disease, and was present in both users and nonusers of oral steroids. Conclusion This study highlights a novel association between FLG‐null mutations and an increased susceptibility to recurrent bacterial skin infection among patients with AD.     

Filaggrin polymorphism P478S, IgE level, and atopic phenotypes

Background Whether environmental exposures may modulate the effect of the skin barrier gene on atopic dermatitis (AD) remains to be elucidated. Objectives To determine whether filaggrin (FLG) variants can serve as a predictor for atopic disorders in Chinese individuals and if allergen exposures may modify the effect of FLG variants on AD by total IgE levels. Methods In total, 116 children aged 2–5 years with AD and 212 control subjects were analysed for the FLG variants using DNA sequencing. Multiple logistic regression models were performed to estimate the association among FLG polymorphisms and atopic phenotypes. Serum total IgE level, standing for the degree of allergen exposures, was later stratified to determine the effects of FLG polymorphisms on AD. Results A significant difference in genotype frequency was found among AD cases and controls in FLG P478S polymorphism. FLG P478S GG genotype significantly increased the risk of AD [odds ratio (OR) 4·60, 95% confidence interval (CI) 1·88–11·24]. In addition, among subjects with AD, GG genotypes also significantly increased the risk of developing asthma (OR 4·68, 95% CI 1·37–16·03). Further, a similar result was obtained for allergic rhinitis (OR 3·23, 95% CI 1·01–10·30). Interestingly, the P478S GG genotype was significantly related to AD (OR 5·67, 95% CI 1·93–16·60) in children with IgE level ≥ 100 kU L^?1. However, the association was not evident when IgE level was < 100 kU L^?1. Conclusions Our results suggest that the FLG P478S polymorphism may confer susceptibility to the development of AD among Chinese individuals and may be modified by IgE levels.     

Correlation between serum 25‐hydroxyvitamin D levels and severity of atopic dermatitis in children

Background Vitamin D deficiency could be associated with the prevalence of atopic dermatitis (AD). Objectives We carried out a study to see whether deficient/insufficient levels of vitamin D correlate with the severity of atopic skin disease. Methods Using the SCORAD index, we evaluated the severity of disease in 37 children (17 girls and 20 boys) aged between 8 months and 12 years with AD, consecutively enrolled in the study. Serum levels of 25‐hydroxyvitamin D [25(OH)D] were determined by a chemiluminescent method. Specific IgE (sIgE) to Staphylococcus aureus enterotoxins and sIgE to Malassezia furfur were assayed by the ImmunoCAP system. anova and the Pearson correlation test were used for statistical evaluation. Results We found severe, moderate and mild AD in nine (24%), 13 (35%) and 15 (41%) children, respectively. Mean ± SD serum levels of 25(OH)D were significantly higher (P < 0·05) in patients with mild disease (36·9 ± 15·7 ng mL^?1) compared with those with moderate (27·5 ± 8·3 ng mL^?1) or severe AD (20·5 ± 5·9 ng mL^?1). The prevalence of patients with sIgE to microbial antigens increased in relation to vitamin D deficiency and AD severity. Conclusions These data suggest that vitamin D deficiency may be related to the severity of AD and advocate the need for studies evaluating the use of vitamin D as a potential treatment in patients with this disease.     

Individuals with filaggrin‐related eczema and asthma have increased long‐term medication and hospital admission costs

Eczema and asthma are common chronic diseases. Eczema affects 15‐20% of schoolchildren and 2‐10% of adults while asthma affects 16‐18% of the UK population. Almost three‐quarters of children with early onset eczema, a severe and persistent form of eczema, will develop asthma in later life. The filaggrin gene helps produce a protein that creates a protective barrier on the skin against the entry of outside substances that trigger allergies. About 1 in 10 people carry a change in the filaggrin gene and this results in the production of defective protein that can no longer help maintain this skin barrier. This UK study aimed to find whether filaggrin mutations were associated with increased prescribing of medication for eczema and asthma and /or an increased number of asthma exacerbations (i.e. worsening) and whether this translated into different healthcare costs. The study shows that children with eczema and asthma carrying this gene change have substantially increased needs for both eczema and asthma medication through most of their childhood. Children with asthma carrying the gene change were also more prone to suffer asthma attacks over a nine‐year period, enhancing both hospital and human costs of the disease. It follows that a simple ‘spit’ gene test, that can be done anytime in life, including at birth or early childhood, could help predict long‐term healthcare costs and the long‐term risk of more severe disease for individuals with common chronic conditions such as eczema and asthma. Children and adults with filaggrin gene mutations may benefit from targeted treatment regimes, such as daily use of emollients from birth, which could lead to cost savings for healthcare systems and improvements in disease control and quality‐of‐life.     

What’s new in atopic eczema? An analysis of systematic reviews published in 2008 and 2009

This review summarizes clinically important findings from nine systematic reviews of the causes, treatment and prevention of atopic eczema (AE) published between August 2008 and August 2009. Two systematic reviews concluded that there is a strong and consistent association between filaggrin (FLG) mutations and development of eczema. The associations between FLG mutations and atopic sensitization, rhinitis and asthma are weaker than between FLG mutations and eczema, especially if those who also have eczema are excluded. The relationship between transforming growth factor levels in breast milk and eczema development is still unclear. A further systematic review found no strong evidence of a protective effect of exclusive breastfeeding for at least 3 months against eczema, even in those with a positive family history of atopy. Based on a systematic review and meta-analysis of six randomized controlled trials, supplementation with omega-3 and omega-6 oils is unlikely to play an important role in the primary prevention of eczema or allergic diseases in general. There is little evidence to support dietary restrictions of certain foods in unselected children with AE. There is also little evidence to suggest a clinically useful benefit from using probiotics in patients with established eczema. A systematic review of topical pimecrolimus and tacrolimus added little additional information to previous reviews, and did not provide any new data on long-term safety. Both of these drugs work in AE, and may reduce flares and usage of topical corticosteroids; however, there is still uncertainty about how they compare with topical corticosteroids.     

Genotype–phenotype associations in filaggrin loss‐of‐function mutation carriers

Background. Loss‐of‐function mutations in the filaggrin gene (FLG) have been reported to be associated with specific phenotypic characteristics such as hyperlinearity and keratosis pilaris. Objectives. To study phenotypic features in patients with occupational irritant contact eczema of the hands in relation to FLG loss‐of‐function mutations. Materials and methods. In a prospective cohort study, genotype was determined for 459 study subjects for four FLG null alleles, and investigated for selected history, clinical and laboratory features. Results. Overall, 68 patients showed a mutation in the FLG alleles R501X, R2447X, S3247X, and/or 2282del4. Flexural eczema, xerosis cutis, pityriasis alba, dirty neck, pulpitis sicca, hyperlinear palms, keratosis pilaris and family history of eczema were positively associated with FLG mutations (p < 0.05). Although we observed a statistically significant correlation with higher serum IgE in FLG mutation carriers, allergic rhinoconjunctivitis and allergic asthma were not over‐represented in this group. Conclusion. This study shows further genotype–phenotype correlations in patients with occupational irritant contact eczema and FLG mutation carrier status. These features may help to identify those with FLG mutations on a specific phenotype basis.     

Ichthyosis vulgaris: the filaggrin mutation disease

Ichthyosis vulgaris is caused by loss‐of‐function mutations in the filaggrin gene (FLG) and is characterized clinically by xerosis, scaling, keratosis pilaris, palmar and plantar hyperlinearity, and a strong association with atopic disorders. According to the published studies presented in this review article, FLG mutations are observed in approximately 7·7% of Europeans and 3·0% of Asians, but appear to be infrequent in darker‐skinned populations. This clinical review article provides an overview of ichthyosis vulgaris epidemiology, related disorders and pathomechanisms. Not only does ichthyosis vulgaris possess a wide clinical spectrum, recent studies suggest that carriers of FLG mutations may have a generally altered risk of developing common diseases, even beyond atopic disorders. Mechanistic studies have shown increased penetration of allergens and chemicals in filaggrin‐deficient skin, and epidemiological studies have found higher levels of hand eczema, irritant contact dermatitis, nickel sensitization and serum vitamin D levels. When relevant, individuals should be informed about an increased risk of developing dermatitis when repeatedly or continuously exposed to nickel or irritants. Moreover, with our current knowledge, individuals with ichthyosis vulgaris should be protected against neonatal exposure to cats to prevent atopic dermatitis and should abstain from smoking to prevent asthma. Finally, they should be advised against excessive exposure to factors that decrease skin barrier functions and increase the risk of atopic dermatitis.     

Tiled array‐based sequencing identifies enrichment of loss‐of‐function variants in the highly homologous filaggrin gene in African‐American children with severe atopic dermatitis

Filaggrin (FLG) loss‐of‐function (LOF) variants are a major risk factor for the common inflammatory skin disease, atopic dermatitis (AD) and are often population‐specific. African‐American (AA) children are disproportionately affected with AD, often later developing asthma and/or allergic rhinitis and comprise an atopy health disparity group for which the role of FLG LOF is not well known. Discovery of FLG LOF using exome sequencing is challenging given the known difficulties for accurate short‐read alignment to FLG's high homology repeat variation. Here, we employed an array‐based sequencing approach to tile across each FLG repeat and discover FLG LOF in a well‐characterized cohort of AA children with moderate‐to‐severe AD. Five FLG LOF were identified in 23% of our cohort. Two novel FLG LOF singletons, c.488delG and p.S3101*, were discovered as well as p.R501*, p.R826* and p.S3316* previously reported for AD. p.S3316* (rs149484917) is likely an African ancestral FLG LOF, reported in African individuals in ExAC (Exome Aggregation Consortium), Exome Variant Server (ESP), and 4 African 1000G population databases (ESN, MSL, ASW, and ACB). The proportion of FLG LOF (11.5%) among the total FLG alleles in our cohort was significantly higher in comparisons with FLG LOF reported for African individuals in ExAC (2.5%; P = 4.3 × 10^?4) and ESP (1.7%; P = 3.5 × 10^?5) suggesting a disease‐enrichment effect for FLG LOF. Our results demonstrate the utility of array‐based sequencing in discovering FLG LOF, including novel and population‐specific, which are of higher prevalence in our AA severe AD group than previously reported.     

Impact of filaggrin mutations on Raman spectra and biophysical properties of the stratum corneum in mild to moderate atopic dermatitis

Background Atopic dermatitis (AD) is associated with null mutations in the filaggrin (FLG) gene. Objective To assess the impact of FLG null mutations on biophysical properties and the molecular composition of the stratum corneum (SC) in healthy individuals and AD patients. Methods A total of 196 French adults, including 97 with a history of mild to moderate AD, were genotyped for the three major European FLG mutations. Components of the natural moisturizing factor (NMF), lipids and water content in the SC were determined using Raman spectroscopy. In addition, trans‐epidermal water loss, capacitance and pH of the SC were measured. Results Stratum corneum concentrations of total NMF, water, ornithine and urocanic acid (UCA) were significantly lower in AD patients than in healthy controls. Null mutations of FLG were detected in 4% of controls and 10% of AD patients. FLG mutations were associated with increased SC levels of lactate, reduced concentrations of most other NMF components and higher disease severity in AD patients. In AD patients without FLG mutations, the content of NMF constituents decreased with increasing disease severity. The concomittant presence of low concentrations of histidine, alanine and either glycine or pyrrolidone‐5‐carboxylic acid (PCA) in the SC was associated with FLG mutations with 92% specificity. Conclusions Our findings suggest a low prevalence of FLG mutations in mild AD and support an important role for filaggrin in determining the physicochemical parameters of the SC. The combined measurement of several filaggrin breakdown products in the SC may be useful to specifically predict the presence of FLG mutations.     

Eczema and cancer risk: a critical appraisal and review of the literature

Aim Hwang et al. aimed to evaluate the risk of malignancy among individuals with eczema, allergic rhinitis (AR) and asthma, compared with the general Taiwanese population. Hypothesis People with atopic conditions, including eczema, have an altered risk of malignancy. Setting and design This was a prospective nationwide cohort study. The authors used the Taiwanese National Health Insurance Research Database (NHIRD) to compare the incidence of cancers among people with established allergic disease relative to the risk in the general population. Study exposure Exposure was the presence of one or more atopic conditions (eczema, AR or asthma). Data were extracted on 997 729 randomly selected people registered on the NHIRD at any time point between 1996 and 2008. Eczema was identified via ICD‐9‐CM codes with the diagnosis being made by a dermatologist, paediatrician or allergist. Follow‐up was until 2008, date of first cancer or death. Outcomes The outcome was a new diagnosis of malignancy, identified via catastrophic illness insurance certificates, again using ICD‐9‐CM diagnostic codes. Primary outcome measure Standardized incidence ratios (SIRs) for cancers overall and different types of malignancy among patients with eczema, AR or asthma were calculated against the expected number of cancer cases in the general population, adjusted for age and sex. Results The number of patients identified with eczema, AR and asthma was 34 263, 225 315 and 107 601, respectively. Overall cancer rates in patients with these conditions were not significantly different from those in the general population [SIR eczema = 0·97 (95% confidence interval 0·87–1·09), SIR AR = 1·02 (0·98–1·05) and SIR asthma = 1·01 (0·97–1·04)]. However, when the results for eczema were stratified by age, people aged between 20 and 39 years appeared to have a 56% increase in risk in relation to ‘any cancer’ [SIR = 1·56 (1·13–2·09)]. Looking at individual cancer types in patients with eczema, only the risk of brain cancer was significantly raised [SIR = 2·52 (1·15–4·79)]. Patients who had had all three allergic conditions had a reduced SIR for ‘cancers overall’ [SIR = 0·59 (0·37–0·88)]. This inverse association was less strong for those with eczema and asthma [SIR = 0·73 (0·55–0·97)] or asthma and AR [SIR = 0·79 (0·73–0·84)] and statistically only of borderline significance for those with eczema and AR [SIR = 0·85 (0·67–1·07)]. Conclusions Hwang et al. conclude that the relationship between allergic diseases and cancer risk is complex and site specific. The risk of malignancy was highest in all atopic conditions in the 20–39‐year age group. In patients with eczema, the incidence of brain cancer was higher than expected, which the authors note is at odds with previous studies. However, numbers were too small to allow stratification by histological subtypes. The authors warn against deriving conclusions for rarer cancers and that borderline SIRs must be interpreted with caution.     

Eczema in early childhood is strongly associated with the development of asthma and rhinitis in a prospective cohort

ABSTRACT: BACKGROUND: This study aimed to estimate the association between eczema in early childhood and the onset of asthma and rhinitis later in life in children. METHODS: A total of 3,124 children aged 1-2 years were included in the Dampness in Building and Health (DBH) study in the year 2000, and followed up 5 years later by a parental questionnaire based on an International Study of Asthma and Allergies in Childhood protocol. The association between eczema in early childhood and the incidence of asthma and rhinitis later in life was estimated by univariable and multivariable logistic regression modelling. RESULTS: The prevalence of eczema in children aged 1-2 years was 17.6 % at baseline. Children with eczema had a 3-fold increased odds of developing asthma (adjusted odds ratio [aOR], 3.07; 95 % confidence interval (CI) 1.79-5.27), and a nearly 3-fold increased odds of developing rhinitis (aOR, 2.63; 1.85-3.73) at follow-up compared with children without eczema, adjusted for age, sex, parental allergic disease, parental smoking, length of breastfeeding, site of living, polyvinylchloride flooring material, and concomitant allergic disease. When eczema was divided into subgroups, moderate to severe eczema (aOR, 3.56; 1.62-7.83 and aOR, 3.87; 2.37-6.33, respectively), early onset of eczema (aOR, 3.44; 1.94-6.09 and aOR, 4.05; 2.82-5.81; respectively), and persistence of eczema (aOR, 5.16; 2.62-10.18 and aOR, 4.00; 2.53-6.22, respectively) further increased the odds of developing asthma and rhinitis. Further independent risk factors increasing the odds of developing asthma were a parental history of allergic disease (aOR, 1.83; 1.29-2.60) and a period of breast feeding shorter than 6 months (aOR, 1.57; 1.03-2.39). The incidence of rhinitis was increased for parental history of allergic disease (aOR, 2.00; 1.59-2.51) and polyvinylchloride flooring (aOR, 1.60; 1.02- 2.51). CONCLUSION: Eczema in infancy is associated with development of asthma and rhinitis during the following 5-year period, and eczema is one of the strongest risk factors. Early identification is valuable for prediction of the atopic march.