Atopic dermatitis

Effect of gestational oily fish intake on the risk of allergy in children may be influenced by FADS1/2, ELOVL5 expression and DNA methylation

Background

Evidence suggests that prenatal exposure to n-3 long-chain polyunsaturated fatty acids (LCPUFA) reduces the incidence of allergic disease in children. LCPUFAs are produced from dietary precursors catalyzed by desaturases and elongases encoded by the FADS1/2 and ELOVL5 genes. DNA methylation regulates gene activity and fatty acid supplementation could alter DNA methylation (DNA-M) at these genes. We investigated whether DNA-M and expression of the FADS1/2 and ELOVL5 genes were associated with allergy in children and gestational fish intake. We studied 170 participants from the Isle of Wight 3rd Generation Cohort, UK. Phenotype data and exposure was assessed by questionnaires. Genome-wide DNA-M in cord blood samples was quantified using the Illumina Infinium HumanMethylation450 and EPIC Beadchips. Five SNPs (single-nucleotide polymorphisms) in the FADS gene cluster and one SNP in ELOVL5 were genotyped in offspring. FADS gene expression in offspring cord blood was determined.

Results

Gestational fish intake was significantly associated with increased methylation of cg12517394 (P = 0.049), which positively correlated with FADS1 mRNA levels (P = 0.021). ELOVL5 rs2397142 was significantly associated with eczema (P = 0.011) and methylation at cg11748354 and cg24524396 (P < 0.001 and P = 0.036, respectively). Gestational fish intake was strongly associated with elevated DNA-M at cg11748354 and cg24524396 (P = 0.029 and P = 0.002, respectively) and reduced ELOVL5 mRNA expression (P = 0.028).

Conclusion

The association between induced FADS1/2 and ELOVL5 DNA-M and reduced gene expression due to gestational fish intake provide a mechanistic explanation of the previously observed association between maternal LCPUFA intake and allergy development in early childhood.

Electronic supplementary material

The online version of this article (10.1186/s12263-019-0644-8) contains supplementary material, which is available to authorized users.

Association of Single-Nucleotide Polymorphisms of the MBL2 with Atopic Dermatitis in Korean Patients

BACKGROUND

Human mannose-binding lectin (MBL) is a serum lectin taking part in the innate immunity by opsonizing various microorganisms for phagocytosis. The MBL serum concentration is affected by several single-nucleotide polymorphisms (SNPs) in the promoter region of the MBL2 gene.

OBJECTIVE

The purpose of this study was to examine the relationship between MBL2 polymorphisms and atopic dermatitis (AD) susceptibility.

METHODS

To examine whether the MBL2 SNPs are related to AD susceptibility, we examined 237 patients with AD and 94 controls by polymerase chain reaction (PCR)-restriction fragment length polymorphism and PCR-sequence specific primer analyses of four polymorphic loci: two (H/L and X/Y) within the promoter region and the other two (P/Q and A/B) within exon 1. MBL concentrations in the blood were estimated by ELISA.

RESULTS

The prevalence of haplotype HYPB, leading to MBL deficiency, was significantly decreased in the AD patients compared to the controls (p=0.002), while the prevalence of haplotype HYPA was increased with a clear trend toward significance (p=0.056). The frequency of MBL2 LYPB/LXPA (odds ratio, 0.08; 95% confidence interval, 0.009~0.655; p=0.021) were significantly decreased in the AD patients. The blood log [total immunoglobulin E, IgE] levels of MBL2 HYPA/HYPA, HYPA/LYPA, HYPA/LYPB, HYPA/LYQA, and LYQA/LXPA haplotype pairs were significantly increased in the AD patients.

CONCLUSION

The frequency of MBL2 HYPB haplotype was significantly decreased in the AD patients compared to the controls. The frequency of LYPB/LXPA had a possibly protective effect on AD. Moreover, the MBL2 HYPA haplotype pairs, which were related to higher blood total IgE levels, were possibly associated with extrinsic AD.

Ambient Air Pollution, Meteorological Factors and Outpatient Visits for Eczema in Shanghai, China: A Time-Series Analysis

Environmental irritants are important risk factors for skin diseases, but little is known about the influence of environmental factors on eczema incidence. In this time-series study, our objective was to examine the associations of environmental factors with outpatient visits for eczema. Daily outpatient visits between 2007 and 2011 (1826 days) were collected from Huashan Hospital in Shanghai, China. We used an overdispersed generalized additive model to investigate the short-term association between environmental factors and outpatient visits for eczema. Daily outpatient visits for eczema were significantly associated with air pollution and meteorological factors. For example, a 10 μg/m³ increase of 7-day (lag 06) average concentrations of PM₁₀ (particulate matter no greater than 10 microns), SO₂, NO₂ was associated with 0.81% (95% confidence intervals (CI) 0.39%, 1.22%), 2.22% (95% CI: 1.27%, 3.16%) and 2.31% (95% CI: 1.17%, 3.45%) increase in outpatient visits for eczema, respectively. A 10 °C elevation of temperature on lag 0 day were associated with 8.44% (95% CI: 4.66%, 12.22%) increase in eczema visits, whereas 10 unit decrease of 7-day average relative humidity were associated with 10.86% (95% CI: 8.83%, 12.89%) increase in eczema visits. This study provided clear evidence of ambient air pollution, high temperature and low relative humidity on increasing the incidence of eczema in Shanghai, China.

Atopic Dermatitis: Clinical Connotations, Especially a Focus on Concomitant Atopic Undertones in Immunocompromised/Susceptible Genetic and Metabolic Disorders

Atopic dermatitis (AD) is an intriguing clinical entity. Its clinical connotations are varied, the updates of which are required to be done periodically. An attempt to bring its various facets have been made highlighting its clinical features keeping in view the major and the minor criteria to facilitate the diagnosis, differential diagnosis, complications, and associated dermatoses. The benefit of the current dissertation may percolate to the trainees in dermatology, in addition to revelations that atopic undertones in genetic susceptibility and metabolic disorder may provide substantive insight for the future in the understanding of thus far enigmatic etiopathogenesis of AD.

Relationship between serum 25-hydroxyvitamin D and interleukin-31 levels, and the severity of atopic dermatitis in children

PURPOSE

Atopic dermatitis (AD) is a chronic inflammatory relapsing skin disorder. Vitamin D plays a pivotal role in the development of AD, and interleukin (IL) 31 is known to be related to pruritus in AD. The aim of our study was to determine whether 25-hydroxyvitamin D (25(OH)D) levels are related to IL-31 levels or to the severity of AD.

METHODS

We enrolled 91 children with AD and 32 control subjects without history or symptoms of allergic diseases. Blood was drawn to evaluate complete blood cell count, total eosinophil count (TEC), and total IgE, specific IgE to common allergens, 25(OH)D, and IL-31 levels. Serum 25(OH)D and IL-31 levels were measured using high-performance liquid chromatography and enzyme-linked immunosorbent assay, respectively. The scoring atopic dermatitis (SCORAD) index was used to evaluate the severity of AD.

RESULTS

The mean 25(OH)D level was significantly lower in the AD group than in the control group; 25(OH)D decreased greatly in the moderate and severe AD groups compared with the mild AD group. Children with atopic sensitization showed significantly lower 25(OH)D levels than nonatopic children. However, serum IL-31 levels were not related to AD group, SCORAD index, or 25(OH)D levels. The SCORAD index was inversely correlated with serum 25(OH)D level and positively correlated with TECs and total IgE levels. Children with moderate and severe AD had significantly higher TECs than children with mild AD.

CONCLUSION

Vitamin D is related to the severity of AD independently of IL-31.

Cognitive Behavioural Stress Management as Treatment of Atopic Dermatitis: A Case Study

A 37-year-old male with a 13-year history of atopic dermatitis (AD) was treated with cognitive behavioural stress management. Self-rated stress and extent of AD rash decreased from baseline to the end of treatment, and gains were maintained at follow-up. A significant correlation between stress and extent of AD rash was observed. Discussion focused on the possible role of stress induced immunosuppression on exacerbations of AD, and the need for controlled trials evaluating the treatment procedures used in the current study.

Effects of low-dose-gamma rays on the immune system of different animal models of disease

We reviewed the beneficial or harmful effects of low-dose ionizing radiation on several diseases based on a search of the literature. The attenuation of autoimmune manifestations in animal disease models irradiated with low-dose γ-rays was previously reported by several research groups, whereas the exacerbation of allergic manifestations was described by others. Based on a detailed examination of the literature, we divided animal disease models into two groups: one group consisting of collagen-induced arthritis (CIA), experimental encephalomyelitis (EAE), and systemic lupus erythematosus, the pathologies of which were attenuated by low-dose irradiation, and another group consisting of atopic dermatitis, asthma, and Hashimoto's thyroiditis, the pathologies of which were exacerbated by low-dose irradiation. The same biological indicators, such as cytokine levels and T-cell subpopulations, were examined in these studies. Low-dose irradiation reduced inter-feron (IFN)-gamma (γ) and interleukin (IL)-6 levels and increased IL-5 levels and the percentage of CD4(+)CD25(+)Foxp3(+)Treg cells in almost all immunological disease cases examined. Variations in these biological indicators were attributed to the attenuation or exacerbation of the disease's manifestation. We concluded that autoimmune diseases caused by autoantibodies were attenuated by low-dose irradiation, whereas diseases caused by antibodies against external antigens, such as atopic dermatitis, were exacerbated.

Acceptability and efficacy of an emollient containing ceramide-precursor lipids and moisturizing factors for atopic dermatitis in pediatric patients

BACKGROUND

Atopic eczema or dermatitis (AD) is associated with atopy and is characterized by reduced skin hydration and an impaired skin barrier in the epidermis. We investigated the patient acceptability and efficacy of an emollient containing ceramide-precursor lipids and moisturizing factors (LMF) in AD.

METHODS

Consecutive AD patients were recruited. Swabs and cultures were obtained from the right antecubital fossa and the worst-affected eczematous area, and disease severity [according to the SCORing Atopic Dermatitis (SCORAD) Index], skin hydration, and transepidermal water loss (TEWL) were measured prior to and after 2 weeks' use of the LMF moisturizer. The general acceptability of treatment was documented as being 'very good', 'good', 'fair', or 'poor'.

RESULTS

Twenty-four AD patients [mean age 13.8 (standard deviation 5.7) years] were recruited. Two thirds of the patients reported very good or good acceptability of the LMF moisturizer, whereas one third reported fair or poor acceptability. There were no inter-group differences in the pre-use clinical parameters of age, objective SCORAD score, pruritus score, sleep disturbance score, skin hydration, TEWL, topical corticosteroid use, oral antihistamine use, or acceptability of previously used proprietary emollients. However, patients in the fair/poor acceptability group were more likely to have Staphylococcus aureus colonization and to be female (odds ratio 13, 95 % confidence interval 1.7-99.4; p = 0.021). Following use of the LMF moisturizer, the objective SCORAD score, pruritus score, and sleep disturbance score were lower in the very good/good acceptability group than in the fair/poor acceptability group. The mean objective SCORAD score improved (from 31.5 to 25.7; p = 0.039) and skin hydration improved [from 30.7 arbitrary units (a.u.) to 36.0 a.u.; p = 0.021] in the very good/good acceptability group. When the data were analyzed for the strength of the agreement of the rating of acceptability, the κ values were 0.338 (fair) for use of body wash and 0.118 (poor) for use of emollients before and after the trial.

CONCLUSION

The LMF moisturizer was considered acceptable by two thirds of the patients with AD. It seems that patients who found the moisturizer acceptable were less likely to be female or to be colonized by S. aureus before switching to the product, and they had less severe eczema, less pruritus, and less sleep disturbance after its use than patients who did not find the product acceptable. Gender and S. aureus colonization may have influenced the patient acceptability and clinical efficacy of the LMF moisturizer. The lack of agreement with regard to the acceptability of the moisturizer implies that there is room for parent/patient education to improve compliance.

Barrier repair therapy in atopic dermatitis: an overview

Atopic eczema or dermatitis (AD) is a chronically relapsing dermatitis associated with pruritus, sleep disturbance, psychosocial symptoms, and impaired quality of life. It affects 10-20 % of school-aged children, and there is evidence to suggest that this prevalence is increasing. Filaggrin (filament-aggregating protein) has an important function in epidermal differentiation and barrier function. Null mutations within the filaggrin gene cause ichthyosis vulgaris and appear to be a major risk factor for developing AD. The affected skin of atopic individuals is deficient in filaggrin degradation products or ceramides. Avoidance of triggering factors, optimal skin care, topical corticosteroids, and calcineurin inhibitors are the mainstays of therapy for AD. Proper moisturizer therapy can reduce the frequency and intensity of flares, as well as the need for topical corticosteroids or topical calcineurin inhibitors. Recent advances in the understanding of the pathophysiological process of AD involving filaggrin and ceramides has led to the concept of barrier therapy and the production of new moisturizers and topical skin products targeted to correct reduced amounts of ceramides and natural moisturizing factors in the skin with natural moisturizing factors, ceramides, and pseudoceramide products. Emollients, both creams and ointments, improve the barrier function of the stratum corneum by providing it with water and lipids. Studies on AD and barrier repair treatment show that adequate lipid replacement therapy reduces the inflammation and restores epidermal function. We reviewed 12 randomized trials and 11 cohort studies and found some evidence that certain products had therapeutic efficacy in improving clinical and/or biophysical parameters of patients with AD. Nevertheless, study methods were often flawed and sample sizes were small. Additional research is warranted to better understand the optimal formulary compositions. Also, long-term studies would be important to evaluate whether lipid barrier replacement therapy reduces bacterial colonization or prevents progression of the atopic march.

Efficacy and safety of topical WBI-1001 in patients with mild to severe atopic dermatitis: results from a 12-week, multicentre, randomized, placebo-controlled double-blind trial

BACKGROUND

There is a need for the development of novel nonsteroidal topical drugs for the treatment of atopic dermatitis (AD).

OBJECTIVES

The primary objective was to evaluate the efficacy of WBI-1001 over 6 weeks of treatment of mild to severe AD.

METHODS

  Patients with AD affecting 3-20% of their body surface area and with an Investigator's Global Assessment (IGA) of 2-4 were randomized (1 : 1 : 1) to receive placebo, WBI-1001 0·5% or WBI-1001 1·0% in a cream formulation applied twice daily for 6 weeks. At the end of this phase, patients receiving WBI-1001 continued the same treatment for an additional 6 weeks. Patients receiving placebo entered into a 6-week double-blind phase with re-randomization (1 : 1) to WBI-1001 0·5% or 1·0% cream. The primary objective was to evaluate the efficacy of WBI-1001 over 6 weeks of treatment of mild to severe AD. The primary endpoint was the mean change from baseline in IGA at day 42 (week 6).

RESULTS

In total, 148 patients were randomized and analysed in the placebo (51), WBI-1001 0·5% (50) and WBI-1001 1·0% (47) groups. There was a decrease of 1·3 [43%; P < 0·001; 95% confidence interval (CI) -1·2 to -0·5] and 1·8 (56·3%; P < 0·001; 95% CI -1·6 to -0·9) in IGA at day 42 in the WBI-1001 0·5% and 1·0% groups, respectively, as compared with a decrease of 0·5 (14·7%) in the placebo group. Adverse drug reactions included a few cases of folliculitis and contact dermatitis.

CONCLUSIONS

WBI-1001 is an efficacious novel topical anti-inflammatory molecule for the treatment of AD.

Hint for association of single nucleotide polymorphisms and haplotype in SPINK5 gene with atopic dermatitis in Koreans

Clinical studies, including twin studies, support the concept that the risk of atopic dermatitis (AD) may be mediated through skin-specific genes, rather than simply through systemic immune or atopy risk genes. The SPINK5 gene is expressed on epithelial surfaces and may provide protection against other allergenic serine proteases. Mutations in the SPINK5 gene result in Netherton syndrome, a disorder characterised by AD, ichthyosis, and elevated serum IgE levels. We genotyped 21 single nucleotide polymorphisms (SNPs) from the SPINK5 gene for 1090 case-control samples (631 patients with AD and 459 normal controls) and analysed the SNPs and haplotypes in this gene and also searched for gene-gene interactions between SPINK5 and the DEFB1 gene that we previously reported. Six SNPs [rs17718511 (P = 0.026), rs17860502 (P = 0.024), KN0001820 (P = 0.045), rs60978485 (P = 0.007), rs17718737 (P = 0.02), and rs1422985 (P = 0.038)] and the haplotype TAA (rs60978485, rs6892205, rs2303064; P = 0.023) in the SPINK5 gene showed significant different allelic or genotypic distributions between the AD group and the control group. We also found that four SNPs [rs17718511 (P = 0.033), rs17860502 (P = 0.031), rs60978485 (P = 0.005), rs17718737 (P = 0.023)] and the haplotype TAA (P = 0.02) in the SPINK5 gene showed associations with the susceptibility of the allergic type of AD (ADe). In addition to this finding, we speculate that the SNPs from DEFB1 and SPINK5 affect the individual susceptibility to development of ADe in an additive manner. This study provides evidence for a significant interaction between allergens and the SPINK5 gene that may contribute to ADe susceptibility.

An atopic dermatitis-like skin disease with hyper-IgE-emia develops in mice carrying a spontaneous recessive point mutation in the Traf3ip2 (Act1/CIKS) gene

Spontaneous mutant mice that showed high levels of serum IgE and an atopic dermatitis (AD)-like skin disease were found in a colony of the KOR inbred strain that was derived from Japanese wild mice. No segregation was observed between hyper-IgE-emia and dermatitis in (BALB/c x KOR mutant) N(2) mice, suggesting that the mutation can be attributed to a single recessive locus, which we designated adjm (atopic dermatitis from Japanese mice). All four adjm congenic strains in different genetic backgrounds showed both hyper-IgE-emia and dermatitis, although the disease severity varied among strains. Linkage analysis using (BALB/c x KOR-adjm/adjm) N(2) mice restricted the potential adjm locus to the 940 kb between D10Stm216 and D10Stm238 on chromosome 10. Sequence analysis of genes located in this region revealed that the gene AI429613, which encodes the mouse homologue of the human TNFR-associated factor 3-interacting protein 2 (TRAF3IP2) protein (formerly known as NF-kappaB activator 1/connection to IkappaB kinase and stress-activated protein kinase/Jun kinase), carried a single point mutation leading to the substitution of a stop codon for glutamine at amino acid position 214. TRAF3IP2 has been shown to function as an adaptor protein in signaling pathways mediated by the TNFR superfamily members CD40 and B cell-activating factor in epithelial cells and B cells as well as in the IL-17-mediated signaling pathway. Our results suggest that malfunction of the TRAF3IP2 protein causes hyper-IgE-emia through the CD40- and B cell-activating factor-mediated pathway in B cells and causes skin inflammation through the IL-17-mediated pathway. This study demonstrates that the TRAF3IP2 protein plays an important role in AD and suggests the protein as a therapeutic target to treat AD.

Therapeutic effects of Baicalein on atopic dermatitis-like skin lesions of NC/Nga mice induced by dermatophagoides pteronyssinus

The present study was conducted to investigate the effects of Baicalein (BE), which is hydrolyzed product of Baicalin (BA), on atopic dermatitis (AD). AD was induced in NC/Nga mice by DPE treatment. BE hydrogels treatment reduced the levels of skin severity scores. BE hydrogels treatment also decreased inflammatory cytokines such as TNF-alpha, IL-6, and its level in the serum. BE hydrogels treatment elevated IFN-gamma level in the spleenocyte culture supernatant. Cell numbers in the skin positive to CD3+/CD69+, CCR3+, CD11b+/Gr-1+, B220+/IgE+ all of which were up-regulated in AD-induced mice were decreased and returned to normal levels. Histological examination showed that infiltration levels of immune cells in the skin of AD-induced NC/Nga mice were much improved by BE hydrogels treatment. These results thus suggest that BE can regulate molecular mediators and immune cells that are functionally associated with atopic dermatitis induced in NC/Nga mice, and may play an important role in recovering AD symptoms.

Expansion of FOXP3-positive CD4+CD25+ T cells associated with disease activity in atopic dermatitis

BACKGROUND

FOXP3-positive CD4+CD25+ T cells are known to have an immunoregulatory function by means of preventing T-cell reactivity to both self- and non-self-antigens. However, the role of these cells in the pathogenesis of allergic diseases is not clear.

OBJECTIVE

To evaluate the quantity and quality of circulating FOXP3-positive T cells in patients with atopic dermatitis (AD).

METHODS

Peripheral blood mononuclear cells were isolated from 35 AD patients (mean [SD] age, 27.1 [7.5] years) and 36 controls (mean [SD] age, 27.5 [10.0] years). Cellular FOXP3 expression was analyzed using flow cytometry. Characteristics of FOXP3-positive T cells were evaluated with respect to cytokine production capability and suppressive function.

RESULTS

Frequencies of circulating FOXP3+CD25+ cells in the CD4+ T-cell population of AD patients were significantly higher than those in controls (mean [SD], 7.4% [4.6%] vs 4.5% [1.3%]; P = .002) and correlated with their Scoring Atopic Dermatitis (SCORAD) scores (r = 0.74, P = .008) and peripheral blood eosinophil counts (r = 0.72, P < .001). In the patients whose samples were analyzed at intervals of 1 to 2 months, frequencies of FOXP3-positive T cells were decreased as their skin lesions improved, regardless of medicines used. FOXP3-positive CD4+ T cells from patients, as well as those from controls, showed little capability to synthesize interferon gamma and interleukin 4. No differences were found in suppression abilities of CD4+CD25+ T cells between AD patients and controls.

CONCLUSIONS

Our data suggest that dynamic fluctuation in numbers of circulating FOXP3-positive regulatory T cells might contribute to the pathogenesis of AD.

UVA/UVB phototherapy for atopic dermatitis revisited

BACKGROUND

Atopic dermatitis (AD) is a genetically determined pruritic skin disease affecting predominantly young people. The therapy of AD includes mainly corticosteroids (CS), antihistamines and immunosuppressors. CS are known to cause a variety of side effects and attempts have been made to reduce or eliminate their use through alternative methods such as phototherapy (UVA/UVB, UVA(1), UVB 311 nm). In order to optimize therapeutic efficacy the effects of CS and UV radiation are often combined.

OBJECTIVE

To evaluate the efficacy of UVA/UVB and UVA/UVB plus topical CS phototherapy of AD and to compare the two regimens with regard to their therapeutic effect, duration of treatment and remissions, cumulative UVA and UVB doses and side effects.

METHODS

Thirty-one patients (mean age 19 years) with moderate-to-severe forms of AD were enrolled in the study (mean disease duration of 17.7 years). Seventeen patients were treated with UVA/UVB phototherapy (Group I). Fourteen patients received UV irradiation combined with topical CS (Group II). The starting UVA dose was 2-2.5 J/cm(2). The initial UVB dose depended on skin phototype. The procedures were held five times weekly. In order to evaluate therapeutic efficacy, 10 severity criteria and 10 topographic sites were scored at the beginning and at the end of treatment.

RESULTS

A statistically significant difference in the severity of the disease was observed before and after phototherapy in both groups (overall clinical score Group I: t=10.1, p=0.0001; Group II: t=13.9, p=0.0001). Erythema (t=12.1, p<0.0001), excoriations (t=10.1, p<0.0001) and vesiculation improved most dramatically after UVA/UVB phototherapy. Lichenification (t=2.5, p=0.024), xerosis (t=10.2, p<0.001) and pruritus (t=13.7, p<0.0001) also diminished significantly. The combination regimen had a similar effect on different severity criteria, but initial signs of improvement appeared earlier. Side effects observed during phototherapy included erythema, burning, skin xerosis and sweating. No statistically significant difference was established between the therapeutic efficacy of the two treatment modalities (t=0.2, p=0.904), but the addition of CS reduced the duration of treatment (number of procedures: t=2.5, p=0.02) and total UVB dose (t=2.3, p=0.03). There was no significant difference between the duration of remissions (t=0.9, p=0.39) and frequency of side effects in the two groups of patients.

CONCLUSION

Both UVA/UVB monotherapy and UVA/UVB + topical CS lead to significant clinical improvement in patients with AD, but the addition of CS reduces the total UVB dose and duration of treatment without influencing the duration of remissions and frequency of side effects.

Psychological stress can trigger atopic dermatitis in NC/Nga mice: an inhibitory effect of corticotropin-releasing factor

Atopic dermatitis (AD) is one of the most common inflammatory diseases of the skin and is usually associated with a family history of atopic diathesis. It has been well established that many environmental or psychological factors aggravate AD. However, it is not clear whether psychological stress by itself can trigger AD. We examined the effect of psychological stress on the onset of AD, using an animal model, the NC/Nga mouse. The animals were exposed to the water avoidance stress (WAS) test to induce psychological stress. Additionally, we examined how corticotropin-releasing factor (CRF) affected the development of AD induced by psychological stress. Under specific pathogen-free (SPF) conditions, NC/Nga mice did not develop AD-like skin lesions. In contrast, NC/Nga mice exposed to psychological stress developed AD-like skin lesions along with elevated levels of serum immunoglobulin E even when kept under SPF conditions. The AD-like skin lesions induced by WAS were completely blocked by pretreating the animals with CRF. Our data indicate that a psychological factor is capable of eliciting AD-like skin lesions in NC/Nga mice. It is possible that the inhibitory effect of CRF may be mediated by the functional modification of various cells that have CRF receptors.

IL-5 and IL-5 receptor alpha polymorphisms are associated with atopic dermatitis in Koreans

BACKGROUND

Eosinophils are recruited into the affected tissue of asthma and atopic dermatitis (AD) patients. IL-5 and IL-5R are highly expressed in the AD skin lesions, yet the reported levels of IL-8 are controversial.

METHOD

We genotyped 17 singlenucleotide polymorphisms (SNPs) from five genes of the 1120 case-control samples (646 AD and 474 controls). We measured the serum IL-5 concentrations in 87 individuals [36 ADe (AD extrinsic), 18 ADi (AD intrinsic) and 33 controls] by ELISA, and compared the results among these groups.

RESULT

The rs2522411SNP and haplotype T-A in the IL-5 gene were significantly associated with the ADe. The serum IL-5 concentration was higher in the ADe than that in the ADi patients without any correlation with the rs2522411SNP. In the IL-5RA gene, the rs334809SNP showed a weak association with AD, and the rs6771148SNP and the haplotype T-C-T of the three adjacent tagged SNPs had an effect on the blood eosinophil counts and the serum ECP levels in the AD patients. However, we could not detect any relationship between AD and the SNPs in the IL-8 and IL-8R genes.

CONCLUSION

We found that the rs2522411SNP and the haplotype T-A in the IL-5 gene and the serum IL-5 levels were strongly associated with the allergic type of AD, but not with the nonallergic type of AD. The association of the rs6771148SNP and the haplotype T-C-T in the IL5RA gene with the blood eosinophil counts and the serum ECP levels indicates that the IL5RA gene has a role for controlling eosinophils in the peripheral blood.

Association of interleukin-10 gene promoter polymorphism in children with atopic dermatitis

The present study evaluated the possible role of interleukin (IL)-10 promoter polymorphisms in children with atopic dermatitis (AD). IL-10 promoter polymorphisms are associated with the phenotype of AD in children.

Atopic dermatitis

Atopic dermatitis is an especially common and frustrating condition, and the prevalence is increasing. The disease can adversely affect the quality of life of patients and caregivers. Significant advances in our understanding of the pathogenesis have led to improvements in therapy. Patient and caregiver education, avoidance of potential triggering factors, optimal skin care, and pharmacotherapy offer the potential for good control for most patients.

Atopic dermatitis

Atopic dermatitis (AD) is an eczematous, highly pruritic chronic inflammatory skin disease. It usually begins early in life and often occurs in people with a personal or family history of asthma and allergic rhinitis. The prevalence is high, especially in children,and it has been rising in recent decades, in parallel with asthma prevalence. Although AD is often described as an "allergic" dis-ease, allergic causation is difficult to document, and AD is increasingly viewed as a skin disease that predisposes to allergies. This interpretation, based on clinical, epidemiologic, and animal stu-dies, may greatly influence our approach to therapy and prevention of atopic diseases in the coming years.

Seasonality in Symptom Severity Influenced by Temperature or Grass Pollen: Results of a Panel Study in Children with Eczema

Although seasonal variations are well known in many patients with eczema, no systematic population-based panel study evaluating seasonality and quantifying the influence of factors like climate and pollen on symptom variations has been conducted so far. Thirty-nine children with eczema, who had been identified in 1996 in a cross-sectional study on 1673 6-y-olds in Augsburg (Germany), participated in the study. Between March and September 1999, they daily recorded itch, extent, and possibly triggering factors on quantitative scales. Daily temperature, humidity, radiation, and pollen concentration were measured. Mixed linear models, taking the time series structure and confounding into account, were used for analysis. Seasonal patterns were significantly different between children: twenty-one had symptoms mainly in winter. They were affected by changes in outdoor temperature: itch was reduced by 22% (95% confidence interval (CI): 16%-27%) and extent by 65% (CI: 54%-72%) per 15 degrees C temperature increase. Eighteen children exhibited more symptoms in summer and especially during days with high grass-pollen exposure when itch was 16% higher (CI: 8%-24%) and extent 19% (CI: 2%-39%). This effect was stronger for children sensitized against pollen. Consideration of the individual type of eczema may help to arrange appropriate preventive and therapeutic measures.

Cutaneous T-cell lymphoma and atopy: is there an association?

BACKGROUND

Case reports have suggested a relationship between atopic diatheses and Sézary syndrome, pre-Sézary syndrome or mycosis fungoides. However, Sézary and pre-Sézary syndromes are rare entities, and this association has never been analysed in greater detail for specific subtypes of cutaneous T-cell lymphoma (CTCL).

OBJECTIVES

To evaluate the prevalence of atopy in subjects with Sézary syndrome, pre-Sézary syndrome or mycosis fungoides, and to compare the rates with the reported prevalence of atopy in the general population.

METHODS

We retrospectively reviewed the records of 157 patients with the diagnosis of Sézary or pre-Sézary syndrome seen between 1965 and 2000, and 102 patients with the diagnosis of mycosis fungoides evaluated from 1994 to 2000 at Mayo Clinic.

RESULTS

Of 157 subjects with Sézary or pre-Sézary syndrome and 102 subjects with mycosis fungoides, 18 and 12, respectively, were identified as having a history of atopic dermatitis, asthma or allergic rhinitis. The prevalence rates of atopy in Sézary or pre-Sézary syndrome and mycosis fungoides were 11.5% (95% confidence interval 6.9-17.5%) and 11.8% (6.2-19.7%), respectively.

CONCLUSIONS

No significant difference exists in the prevalence of atopy in Sézary or pre-Sézary syndrome compared with that in mycosis fungoides (chi2-test, P = 1.00). Furthermore, the rates of atopy in Sézary or pre-Sézary syndrome and mycosis fungoides are not significantly different from the prevalence of atopy in the general population (17-40%). On the basis of these observations, no evidence currently implicates a causal association of CTCL with atopy.

Differential in vivo cytokine mRNA expression in lesional skin of intrinsic vs. extrinsic atopic dermatitis patients using semiquantitative RT-PCR

BACKGROUND

A small subgroup of atopic dermatitis (AD) patients with normal serum IgE levels and without specific IgE sensitization has been termed 'intrinsic type of AD' (ADi) as a counterpart to the term 'extrinsic type of AD' (ADe). However, there are neither molecular markers nor clinically diagnostic tools for distinguishing between ADi and ADe.

OBJECTIVE

The present studies were undertaken to clarify the pathogenesis and in vivo cytokine micromilieu of ADi patients in comparison with ADe patients.

METHODS

We used semiquantitative RT-PCR to investigate the expression of various cytokines and assessed the tissue eosinophil counts in skin biopsies from both types of AD patients.

RESULTS

Although there was no significant difference of cellular infiltrates in the lesional skin between ADe and ADi patients, ADe had significantly increased tissue eosinophilia than ADi. Based on our RT-PCR, the expression patterns of cytokines could be categorized into four groups. The first group includes IL-5, IL-13, and IL-1beta, whose levels of mRNA expression were higher in both types of AD patients than non-atopic (NA) subjects, while ADe patients had even higher levels than ADi patients. The second group includes interferon-gamma (IFN-gamma), IL-12, granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-4, and IL-10, whose levels of mRNA expression were elevated in both types of AD patients without differences between ADe and ADi patients. The third group includes tumour necrosis factor-alpha (TNF-alpha), whose mRNA expression was more decreased in both types of AD patients than NA, and the fourth group includes IL-6 and transforming growth factor-beta (TGF-beta), which did not show any differences among the three groups.

CONCLUSION

These current data demonstrate that the expressions of cytokines IL-5, IL-13, and IL-1beta mRNA and the number of dermal infiltrating eosinophils are increased in ADe patients compared with ADi patients.

Targeting keratinocyte apoptosis in the treatment of atopic dermatitis and allergic contact dermatitis

BACKGROUND

Activation and skin-selective homing of T cells and effector functions in the skin represent sequential events in the pathogenesis of atopic dermatitis and allergic contact dermatitis.

OBJECTIVE

T cell-mediated keratinocyte apoptosis plays a key pathogenetic role in the formation of eczematous dermatitis. IFN-gamma released from activated T cells upregulates Fas on ke-ratinocytes, which renders them susceptible to apoptosis. The lethal hit is given to keratinocytes by means of Fas ligand expressed on the T-cell surface or released to the inflammatory microenvironment. We sought to investigate whether drugs used for the treatment of eczematous disorders interfere with this pathogenic pathway.

METHODS

T cell-mediated, Fas-induced keratinocyte apoptosis in a keratinocyte-T cell coculture system serves as an in vitro model of eczematous dermatitis. We tested, in this model, whether immunomodulatory agents (dexamethasone, cyclosporine A, rapamycine, tacrolimus/FK506, intravenous immunoglobulin [IVIG], and theophylline) are able to inhibit apoptosis of keratinocytes. Additionally, skin biopsy specimens from patients with untreated and successfully treated eczematous dermatitis were evaluated for keratinocyte apoptosis.

RESULTS

Dexamethasone, cyclosporine A, FK506, rapamycine, and IVIG are inhibitors of keratinocyte apoptosis induced by activated T cells. This effect is mediated by 2 major mechanisms directed on T cells or keratinocytes. T-cell activation was mainly inhibited by dexamethasone, FK506, cyclosporine A, and rapamycine. Interestingly, high-dose dexamethasone and IVIG directly inhibited Fas-mediated keratinocyte apoptosis. In vivo keratinocyte apoptosis was significantly reduced after successful topical treatment of eczematous lesions.

CONCLUSION

These results demonstrate mechanisms of action of current treatment approaches and provide a future for more focused therapeutic applications.

The differential fate of cadherins during T-cell-induced keratinocyte apoptosis leads to spongiosis in eczematous dermatitis

Recently we have shown that T-cell-mediated keratinocyte apoptosis plays a key pathogenetic role in the formation of eczematous dermatitis. Spongiosis, the histologic hallmark of eczematous dermatitis, is characterized by impairment of cohesion between epidermal keratinocytes. It is conceivable that the intercellular junction of keratinocytes is an early target of apoptosis-inducing T cells. In this study, we demonstrate that the induction of keratinocyte apoptosis is accompanied by a rapid cleavage of E-cadherin and loss of coimmunoprecipitated beta-catenin. In situ examination of E-cadherin expression and cellular distribution in acute eczematous dermatitis revealed a reduction in keratinocyte membrane E-cadherin in areas of spongiosis. In contrast, the in vitro and in vivo expression of desmosomal cadherins during early apoptosis remained unchanged. Therefore, induction of keratinocyte apoptosis by skin-infiltrating T cells, subseqent cleavage of E-cadherin, and resisting desmosomal cadherins suggests a mechanism for spongiosis formation in eczematous dermatitis.

Impairment of skin barrier function in NC/Nga Tnd mice as a possible model for atopic dermatitis

BACKGROUND

The pathogenesis and aetiology of atopic dermatitis (AD) remain unclear. Establishment of suitable animal models should aid elucidation of the pathogenesis and development of therapy.

OBJECTIVES

We focused on biophysical and biochemical parameters in the skin of NC/Nga Tnd mice to evaluate similarities to and differences from AD.

METHODS

Biophysical (transepidermal water loss and skin surface conductance) and biochemical parameters (ceramide contents and activity of ceramide-metabolizing enzymes) were measured in NC/Nga Tnd mice in which spontaneous dermatitis appeared under ambient laboratory conditions (ALC).

RESULTS

Biophysical parameters suggested impairment of water retention properties and barrier function. The amount of ceramide in NC/Nga Tnd mice under ALC decreased significantly. These dermatological features resembled those of AD, as did the clinical signs and histological changes.

CONCLUSIONS

The results described here and previous immunological studies on AD suggest that the NC/Nga Tnd mouse may be a suitable model for certain aspects of AD.

T cell-mediated Fas-induced keratinocyte apoptosis plays a key pathogenetic role in eczematous dermatitis

Clinical and histologic similarities between various eczematous disorders point to a common efferent pathway. We demonstrate here that activated T cells infiltrating the skin in atopic dermatitis (AD) and allergic contact dermatitis (ACD) induce keratinocyte (KC) apoptosis. KCs normally express low levels of Fas receptor (FasR) that can be substantially enhanced by the presence of IFN-gamma. KCs are rendered susceptible to apoptosis by IFN-gamma when FasR numbers reach a threshold of approximately 40,000 per KC. Subsequently, KCs undergo apoptosis induced by anti-FasR mAb's, soluble Fas ligand, supernatants from activated T cells, or direct contact between T cells and KCs. Apoptotic KCs show typical DNA fragmentation and membrane phosphatidylserine expression. KC apoptosis was demonstrated in situ in lesional skin affected by AD, ACD, and patch tests. Using numerous cytokines and anti-cytokine neutralizing mAb's, we found no evidence that cytokines other than IFN-gamma participate in this process. In addition, apoptosis-inducing pathways other than FasR triggering were ruled out by blocking T cell-induced KC apoptosis by caspase inhibitors and soluble Fas-Fc protein. Responses of normal human skin and cultured skin equivalents to activated T cells demonstrated that KC apoptosis caused by skin-infiltrating T cells is a key event in the pathogenesis of eczematous dermatitis.

Atopic dermatitis

Atopic dermatitis is a chronic skin disorder. It affects up to 15% of the childhood population in the United States and more than half of these patients into adulthood. A clinical diagnosis is made based on the superficial, inflammatory, erythematous and puritic eruptions. Control of symptoms involves patient and parent education with regard to skin care and avoidance of triggers. Treatment includes corticosteroids, with newer strategies emerging.

The modulation of cytokine and IgE production by tumor necrosis factor-beta in atopic dermatitis

Atopic dermatitis (AD) is associated with increased IL-4, IL-5, and IL-13 but decreased IFN-gamma production. This cytokine profile may account for the atopic features of this illness, including IgE upregulation. Recent studies have demonstrated that tumor necrosis factor (TNF)-beta is produced by Th1-like cells, but the cytokine modulation by TNF-beta and the clinical significance of this cytokine in AD is not known. Therefore, this study was carried out to determine the potential role of TNF-beta in AD. In this study, we cultured peripheral blood mononuclear cells from patients with AD and normal subjects with anti-CD3 monoclonal antibodies and investigated the production of TNF-beta by ELISA. The mean +/- SEM of TNF-beta production in AD was significantly lower than normal subjects (p = 0.03). The effect of TNF-beta on cytokine production was investigated by culturing peripheral blood mononuclear cells with anti-CD3 monoclonal antibodies in the presence or absence of TNF-beta. Compared with medium control, TNF-beta significantly decreased IL-5 (p = 0.0004) and IL-13 (p = 0.008) but increased IFN-gamma (p = 0.001) production. The effect of TNF-beta on IgE production was determined by culturing peripheral blood mononuclear cells in the IL-4- and anti-CD40-induced IgE production system. Interestingly, TNF-beta significantly decreased IgE (p = 0.02), but not IgG production compared with medium control. Our study demonstrates that TNF-beta production is downregulated in AD. This cytokine increases IFN-gamma production but decreases IL-5, IL-13, as well as IgE production. These findings suggest a potential role for TNF-beta in the pathogenesis of AD.

Sézary syndrome in a young man with severe atopic dermatitis

Sézary syndrome (SS) is a rare cutaneous T-cell lymphoma. SS usually develops de novo. We describe a 23-year-old man with a proven history of severe atopic dermatitis since childhood, who developed SS. This case contributes to the discussion about the possibility of a relationship between inflammatory dermatitis, atopy and subsequent SS. We provide criteria that should be fulfilled to define such an association.

Soluble E-selectin and eosinophil cationic protein are distinct serum markers that differentially represent clinical features of atopic dermatitis

The serum levels of eosinophil cationic protein (ECP), soluble E-selectin (sE-selectin), soluble CD14 (sCD14) and interleukin (IL)-4 are known to be elevated in patients with atopic dermatitis (AD). However, little is known of the mutual relationship between these factors. To elucidate the clinical and mutual relevance of these markers, we examined the serum levels of ECP, sE-selectin, sCD14 and IL-4 as compared with eruption scores, itch scores, total IgE and numbers of peripheral eosinophils in patients with AD (n = 43), non-atopic eczema (n = 24) and urticaria (n = 13) and in normal individuals (n = 45). In 27 patients with AD the levels of these markers were compared before and after treatment. Levels of ECP were elevated only in the patients with AD, whereas the sE-selectin levels were higher not only in AD but also in non-atopic eczema in a severity-dependent manner. The levels of both markers significantly diminished after treatment. Significant correlations existed between ECP levels and numbers of eosinophils, sE-selectin levels and itch scores, and sE-selectin levels and IgE levels. No significant changes were observed in the sCD14 and IL-4 levels. Taken together, sE-selectin and ECP are good but distinct serum markers that reflect different clinical features of AD.

Enhanced Expression of B7.2 (CD86) in Patients with Atopic Dermatitis: A Potential Role in the Modulation of IgE Synthesis

Recent studies have suggested that the accessory molecules B7.1 (CD80) and B7.2 (CD86) differ in their capacity to generate Th1 vs Th2 responses. Atopic dermatitis (AD) is a chronic allergic skin disease associated with increased IgE synthesis. To determine the potential role of B7.2 molecules in AD, the present study was conducted to compare the expression of B7.1 vs B7.2 on B cells from patients with AD vs normal subjects or patients with psoriasis. The expression of B7.2 on B cells of AD patients (53.67 ± 3.10%) was significantly higher than normals (38.02 ± 4.95%; p = 0.02) and psoriasis patients (40.19 ± 2.70%; p = 0.006). In contrast, there was no significant difference in B7.1 expression among the three subject groups. Interestingly, total serum IgE from AD patients and normal subjects correlated significantly with B7.2 expression on B cells (r = 0.68; p = 0.004), suggesting a role for B7.2+ B cells in IgE synthesis. Indeed, purified B7.2+ B cells produced significantly more IgE than B7.2− B cells in vitro (p = 0.04). Anti-human B7.2, but not B7.1, mAb significantly (p &lt; 0.05) decreased IgE production by PBMC stimulated with IL-4 and anti-CD40 mAb. Furthermore, B7.2+ B cells had a significantly higher level of IL-4R and CD23 expression than B7.1+ B cells. These data demonstrate the predominant expression of B7.2 in AD, but not psoriasis, and a novel role for this molecule in IgE synthesis.

Gamma interferon administration to patients with atopic dermatitis inhibits fibrinolysis and elevates C1 inhibitor

Recombinant human gamma interferon was used to treat 10 atopic dermatitis patients. Recombinant gamma interferon was administered weekly for three consecutive days at 50 microg/M2 SQ for four weeks. All patients' dermatitis improved with recombinant gamma interferon therapy and plasma tumor necrosis factor-alpha levels rose with treatment. Recombinant gamma interferon treatment positively correlated with reduced total plasma fibrinolysis as measured by the fibrin lysis plate, plasmin-alpha2antiplasmin complexes, and tissue type plasminogen activator levels. Accordingly, plasminogen activator inhibitor levels increased. Treatment also was associated with a transient increase in thrombin-antithrombin III complexes. Recombinant gamma interferon resulted in a significant increase in C1 inhibitor antigen but not activity. Plasma prekallikrein, high molecular weight kininogen, and factor XII levels were not decreased. However, 5 of the 10 atopic dermatitis patients before therapy had circulating cleaved plasma high molecular weight kininogen detected on immunoblot, indicating prior kallikrein formation. The cleaved, circulating plasma high molecular weight kininogen disappeared in four out of the five original patients who were reexamined at one year after treatment. These combined data indicated that recombinant gamma interferon treatment reduced total plasma fibrinolysis. In untreated atopic dermatitis, circulating cleaved high molecular weight kininogen also may be a presenting manifestation.

Monitoring of serologic immune parameters in inflammatory skin diseases

This paper deals with the correlation of clinical scoring and serologic markers of inflammation in atopic dermatitis and psoriasis. Serum eosinophil cationic protein (ECP), soluble interleukin-2 receptor (sIL-2R), total serum IgE, IgG and IgM anti-IgE antibodies, and IgE immune complexes were evaluated in monitoring inflammatory skin diseases such as atopic dermatitis and psoriasis. Well-established clinical activity scores were used as standards in recording skin improvement under treatment in a clinical setting. Serum ECP was found to be increased in both atopic dermatitis and psoriasis patients compared to normal controls; sIL-2R and IgE immune complexes were increased only in atopics with increased serum IgE. Anti-IgE antibodies did not show any deviation in both groups of patients. There was a significant elevation of sIL-2R and IgE immune complexes and a nonsignificant elevation of ECP in high-IgE atopics in comparison to those with normal serum IgE. In both groups of patients, there was a significant reduction of ECP and sIL-2R accompanying the improving skin condition. Serum IgE and the other immune parameters failed to respond. In contrast to other studies, serum ECP failed to correspond significantly with disease activity in our study. Our results showed measurable changes of ECP and sIL-2R for atopic dermatitis and/or psoriasis under treatment, but comparison to clinical scores remains difficult due to the different basis of the two systems. The only significant correlation was established for relative changes in sIL-2R and psoriasis area and intensity (PASI), a correlation which might be a useful approach in psoriasis.

Monitoring of disease activity by measurement of inflammatory markers in atopic dermatitis in childhood

Serum levels of soluble interleukin-2 receptor (sIL-2R), intercellular adhesion molecule-1 (ICAM-1), endothelial leukocyte adhesion molecule (ELAM-1), and eosinophil cationic protein (ECP) were measured in 20 patients with atopic dermatitis before and after 4 days' treatment with prednisolone p.o. as well as in 16 healthy, nonatopic controls. Before steroid treatment, patients with atopic dermatitis demonstrated significantly higher serum levels of sIL-2R, ICAM-1, and ECP than healthy controls (P < 0.001), whereas ELAM-1 levels were not different between the groups. After 4 days of steroid treatment, clinical improvement was associated with a decrease of sIL-2R (P < 0.003), ICAM-1 (P < 0.004), and ECP serum levels (P < 0.003), but ELAM-1 levels remained unchanged. Both serum ECP and sIL-2R levels were significantly correlated with disease severity before as well as after steroid treatment. Changes of sIL-2R concentrations were strongly related to the changes of ECP levels. In addition, changes of serum sIL-2R and ECP levels in percentage were correlated with clinical improvement. These results indicate that the determination of sIL-2R and ECP serum levels may be useful in monitoring disease activity in atopic dermatitis in childhood, especially in treatment trials.

Five-year follow-up of high-risk infants with family history of allergy who were exclusively breast-fed or fed partial whey hydrolysate, soy, and conventional cow's milk formulas

BACKGROUND

Allergy is a common cause of illness. The effect of feeding different infant formulas on the incidence of atopic disease and food allergy was assessed in a prospective randomized double-blind study of high-risk infants with a family history of atopy.

METHODS

216 high-risk infants whose mothers had elected not to breast-feed were randomized to receive exclusively a partial whey hydrolysate formula or a conventional cow's milk formula or a soy formula until 6 months of age. Seventy-two high risk infants breast-fed for > or = 4 months were also studied.

RESULTS

Follow-up until 5 years of age showed a significant lowering in the cumulative incidence of atopic disease in the breast-fed (odds ratio 0.422 [0.200-0.891]) and the whey hydrolysate (odds ratio 0.322 [0.159-0.653) groups, compared with the conventional cow's milk group. Soy formula was not effective (odds ratio 0.759 [0.384-1.501]). The occurrence of both eczema and asthma was lowest in the breast-fed and whey hydrolysate groups and was comparable in the cow's milk and soy groups. Similar significant differences were noted in the 18-60 month period prevalence of eczema and asthma. Eczema was less severe in the whey hydrolysate group compared with the other groups. Double-blind placebo-controlled food challenges showed a lower prevalence of food allergy in the whey hydrolysate group compared with the other formula groups.

CONCLUSIONS

Exclusive breast-feeding or feeding with a partial whey hydrolysate formula is associated with lower incidence of atopic disease and food allergy. This is a cost-effective approach to the prevention of allergic disease in children.

Decreased expression of filaggrin in atopic skin

The amounts of the epidermal proteins filaggrin, involucrin, cystatin A and Ted-H-1 antigen produced during the terminal differentiation of keratinocytes were immunohistochemically measured in lesional and nonlesional skin of atopic dermatitis (AD) patients. In addition, the amount of filaggrin in the skin of the inner surface of the upper arm of AD patients (nonlesional skin) and normal controls, obtained by punch biopsy, was measured by an enzyme-linked immunosorbent assay (ELISA) technique. The immunohistochemical study showed that all four proteins were decreased in lesional skin. By contrast, only filaggrin was decreased in nonlesional skin of AD patients. The ELISA showed that the amount of filaggrin in the skin of the inner surface of the upper arm was 2.48 +/- 0.45 microgram/7 mm2 (n = 8) in AD patients, which was 32% of that in the normal controls (7.7 +/- 0.55 microgram/7 mm2; n = 4). This decrease in filaggrin production in atopic skin may be one of the reasons why atopic skin can easily become dry, because filaggrin is thought to be the precursor protein of the emollient factors in the stratum corneum. The evidence that only the expression of filaggrin was suppressed in AD patients, though the genes of filaggrin and involucrin are localized to a very restricted portion of the same gene 1q21, indicates that the filaggrin gene does not share regulatory elements with the involucrin gene.