Intracellular interferon-gamma (IFN-gamma) production in normal children and children with atopic dermatitis

A reduction in the in vitro production of IFN-gamma has been consistently described in atopic dermatitis (AD). Whether this reduction is due to a decrease in the population of peripheral blood mononuclear cells (PBMC) producing IFN-gamma or reduced IFN-gamma production per cell, or a combination of both is not clear. We have examined the intracellular production of IFN-gamma in children with AD and in healthy non-atopic controls. As Staphylococcus aureus colonization is a feature of childhood AD, and is postulated to contribute to the cutaneous inflammation in atopic dermatitis, S. aureus and Staphylococcal enterotoxin B (SEB) were used to activate PBMC. Stimulated PBMC from subjects with AD had significantly fewer IFN-gamma-containing cells in response to SEB (P < 0.001) and S. aureus (P < 0.01) than normal non-atopic children. In addition, SEB-stimulated PBMC from children with AD had less IFN-gamma per cell than normal non-atopic children (P < 0.01). Reduction in the proportion of cells containing IFN-gamma was seen in CD4+, CD8+ and natural killer (NK) cells in PBMC from children with AD. Our findings indicate that reduced production of IFN-gamma observed in childhood AD is due to both a decrease in the number of IFN-gamma-producing cells and a reduced amount of IFN-gamma production per cell. Furthermore, we found that this defect was not confined to CD4+ T cells, suggesting a more generalized defect in IFN-gamma production in childhood AD.     

Molecular analysis of Malassezia microflora on the skin of atopic dermatitis patients and healthy subjects

Members of the genus Malassezia, lipophilic yeasts, are considered to be one of the exacerbating factors in atopic dermatitis (AD). We examined variation in cutaneous colonization by Malassezia species in AD patients and compared it with variation in healthy subjects. Samples were collected by applying transparent dressings to the skin lesions of AD patients. DNA was extracted directly from the dressings and amplified in a specific nested PCR assay. Malassezia-specific DNA was detected in all samples obtained from 32 AD patients. In particular, Malassezia globosa and M. restricta were detected in approximately 90% of the AD patients and M. furfur and M. sympodialis were detected in approximately 40% of the cases. The detection rate was not dependent on the type of skin lesion. In healthy subjects, Malassezia DNA was detected in 78% of the samples, among which M. globosa, M. restricta, and M. sympodialis were detected at frequencies ranging from 44 to 61%, with M. furfur at 11%. The diversity of Malassezia species found in AD patients was greater (2.7 species detected in each individual) than that found in healthy subjects (1.8 species per individual). Our results suggest that M. furfur, M. globosa, M. restricta, and M. sympodialis are common inhabitants of the skin of both AD patients and healthy subjects, while the skin microflora of AD patients shows more diversity than that of healthy subjects. To our knowledge, this is the first report of the use of a nested PCR as an alternative to fungal culture for analysis of the distribution of cutaneous Malassezia spp.     

Molecular analysis of malassezia microflora on the skin of atopic dermatitis patients and healthy subjects]

We compared cutaneous colonization levels of Malassezia species in patients with AD and healthy subjects using nested PCR. Malassezia-specific DNA was detected in all 32 of the patients with AD. M. globosa and M. restricta were detected in approximately 90% of these patients, with M. furfur and M. sympodialis being detected in approximately 40% of the cases. In healthy subjects, Malassezia DNA was detected in 78% of the samples, M. globosa, M. restricta and M. sympodialis were detected at frequencies ranging from 44 to 61%, and M. furfur was found in 11% of healthy subjects. Our results suggest that M. furfur, M. globosa, M. restricta and M. sympodialis are common inhabitants of the skin of both AD patients and healthy subjects, while the skin microflora of patients with AD shows more diversity than that of healthy subjects.     

Anticardiolipin antibodies in children with atopic dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease with a multifactorial etiology. Immunological abnormalities (cell-mediated immune hyperactivity, elevated IgE serum levels and eosinophil-derived mediators) have been observed. In a recent issue, Szakos et al. describe, in children with extrinsic type of AD, an association between the occurrence of anticardiolipin (ACL) IgM and specific IgE against mite, and also in relation to the severity of the disease. We studied 51 children (35 males and 16 females, mean age 44 months) with AD, whose diagnosis was made on the basis of Hanifin and Rajka's criteria. The evaluation of the severity of the disease was made using the SCORAD index. Eleven children had intrinsic type AD (group A); 40 children had extrinsic type AD, 14 of them had specific IgE only against food allergens (group B); 26 children had specific IgE also against inhalant allergens (group C). Twelve children without allergy were designated as the control group. Specific IgEs were determined using the CAP-System (Pharmacia, Uppsala, Sweden) for food and inhalant allergens. The measurement of ACL IgG and IgM was carried out by ELISA (Orgentec Diagnostika, Mainz, Germany). An increase in serum levels of ACL was observed in 13 children (25.5%): 1 child (9%) from group A, 7 children (50%) from group B and 5 children (19.2%) from group C with a statistically significant difference (P=0.038). Our study shows the presence of ACL-IgG above all in extrinsic AD, but no association was found between high levels of ACL and increased severity scoring of AD. Increased levels of ACL were observed in younger children (mean age 26.5 months; P=0.025) especially if sensitized against food allergens.     

Allergic contact dermatitis to nickel in children with atopic dermatitis

We report two atopic boys with allergic contact dermatitis to nickel. Both children had early onset of atopic dermatitis and subsequently presented with infraumbilical dermatitis corresponding to the site of contact with metal snaps. A positive patch test response to 2.5% nickel sulfate in petrolatum was observed in both boys. Allergic contact dermatitis in patients with atopic dermatitis is not uncommon and probably occurs more often than recognized.     

Differences in fecal microflora between patients with atopic dermatitis and healthy control subjects

BACKGROUND: The prevalence of allergic diseases, such as atopic dermatitis (AD), has been increasing. However, few investigations have been made of the intestinal microflora in Japanese patients with AD. OBJECTIVE: The purpose of this study was to determine the differences in microflora, fecal serum IgA concentrations, and skin IgA contents between patients with AD and healthy control subjects. METHODS: This trial was conducted as a case-control study using 30 minor patients with AD and age- and sex-matched healthy control subjects (n = 68). One week after a questionnaire was administered, fecal specimens and 24-hour skin secretion specimens were collected from all subjects. Fecal microflora, fecal IgA concentrations, and IgA contents on the skin surface were analyzed. RESULTS: The counts of Bifidobacterium (in log10 colony-forming units per gram) were significantly lower in patients with AD than in healthy control subjects (9.75 +/- 0.68 vs 10.10 +/- 0.50 log(10) colony-forming units/g, P <.05). In particular, percentages of Bifidobacterium were significantly lower in patients with severe skin symptoms than in those with mild skin symptoms (40% +/- 6% vs 19% +/- 6%, P <.05). In addition, the frequency of occurrence of Staphylococcus was significantly higher in patients with AD than in healthy control subjects (83% vs 59%, P <.05). There were no significant differences in fecal IgA content or IgA content on the skin between the 2 groups. CONCLUSION: Patients with AD had lower counts of Bifidobacterium than healthy control subjects, and the frequency of Staphylococcus was higher in patients with AD than in control subjects. Disorder of the intestinal microflora might play a role in the onset of AD and the aggravation of skin symptoms.     

儿童特应性皮炎血清特异性IgE和斑贴试验结果的临床分析

目的:回顾性分析广州地区特应性皮炎(AD)患儿常见变应原,为AD预防和诊治提供依据.方法:ELISA检测138例AD患儿血清特异性IgE(sIgE),并分析其吸入组、食入组变应原;其中43例患儿同时接受了用于检测日常接触类变应原的皮肤斑贴试验,分析其结果分布特征.结果:吸入性特异性总IgE抗体检测结果阳性率为57.97...     

Molecular and quantitative analyses of Malassezia microflora on the skin of atopic dermatitis patients and genotyping of M. globosa DNA]

To elucidate the role of Malassezia species in atopic dermatitis (AD) requires investigation of the Malassezia microflora on the skin of AD patients. Previously, M. furfur was considered the dominant species in the microflora, however, this microorganism has been reclassified into five species and reanalysis of the microflora based on the current Malassezia taxonomy is therefore needed. Malassezia is more difficult to isolate and culture than other pathogenic yeasts such as Candida and Cryptococcus, making it difficult to elucidate the microflora of AD patients accurately. We developed a PCR-based non-culture method that does not require the use of isolation or culture techniques. Of the members of the genus Malassezia, M. globosa colonized the skin of both AD patients and healthy subjects more frequently than other Malassezia species. In addition, we found polymorphisms in the intergenic spacer 1 region of the M. globosar RNA gene. The genotypes of the microorganisms obtained from AD patients were significantly different from those obtained from healthy subjects. We believe that a specific genotype of M. globosa is responsible for exacerbation of AD.     

Sleep and nighttime pruritus in children with atopic dermatitis

The number of scratching episodes and average frequency with which they started during each sleep stage as well as the effects of nighttime pruritus on objective sleep parameters in nine children with atopic dermatitis were assessed in the sleep laboratory. Scratching episodes occurred during rapid eye movement (REM) sleep and non-REM (NREM) sleep. The largest average frequency corresponded to stage 1, followed by stage 2, REM sleep, stage 4, and stage 3. Sleep maintenance was markedly altered. Total sleep time decrease was related mainly to smaller amounts of stage 4 NREM sleep. REM sleep percentage of total sleep time was increased as compared with normal children of the same age. Furthermore, in six of nine patients REM sleep latency was found to be decreased.     

Temporal shifts in the skin microbiome associated with disease flares and treatment in children with atopic dermatitis

Atopic dermatitis (AD) has long been associated with Staphylococcus aureus skin colonization or infection and is typically managed with regimens that include antimicrobial therapies. However, the role of microbial communities in the pathogenesis of AD is incompletely characterized. To assess the relationship between skin microbiota and disease progression, 16S ribosomal RNA bacterial gene sequencing was performed on DNA obtained directly from serial skin sampling of children with AD. The composition of bacterial communities was analyzed during AD disease states to identify characteristics associated with AD flares and improvement post-treatment. We found that microbial community structures at sites of disease predilection were dramatically different in AD patients compared with controls. Microbial diversity during AD flares was dependent on the presence or absence of recent AD treatments, with even intermittent treatment linked to greater bacterial diversity than no recent treatment. Treatment-associated changes in skin bacterial diversity suggest that AD treatments diversify skin bacteria preceding improvements in disease activity. In AD, the proportion of Staphylococcus sequences, particularly S. aureus, was greater during disease flares than at baseline or post-treatment, and correlated with worsened disease severity. Representation of the skin commensal S. epidermidis also significantly increased during flares. Increases in Streptococcus, Propionibacterium, and Corynebacterium species were observed following therapy. These findings reveal linkages between microbial communities and inflammatory diseases such as AD, and demonstrate that as compared with culture-based studies, higher resolution examination of microbiota associated with human disease provides novel insights into global shifts of bacteria relevant to disease progression and treatment.     

Urinary 17-hydroxycorticosteroids and 17-ketosteroid sulfates in normal children and in children with atopic dermatitis or renal disease

We measured both urinary 17-hydroxycorticosteroids(17-OHCS) and 17-ketosteroid sulfates(17-KS-S) in normal children and in children with some diseases to evaluate adaptation to stress in children. 17-OHCS and 17-KS-S values were measured in morning urine from 60 normal children(3-18 years old) and 24 children with atopic dermatitis or renal disease. In normal children, the 17-OHCS/creatinine showed no difference by age, but both 17-KS-S/creatinine and 17-KS-S/17-OHCS showed significant positive correlation with age. No sex differences were significant. In children with atopic dermatitis or with renal disease treated with cyclosporine A, 17-OHCS/creatinine was significantly higher and the 17-KS-S/17-OHCS ratio was significantly lower than in age-matched controls. These values returned to normal as the conditions improved or as treatment ended. In patients who underwent renal biopsy, both 17-OHCS/creatinine and 17-KS-S/creatinine values were significantly higher after biopsy than before because of the stress caused by pain and complete bed rest. Measurement of urinary 17-OHCS and 17-KS-S in children can be useful for evaluation of adaptation to stress as well as in adults.     

Cytokine modulation of atopic dermatitis filaggrin skin expression

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disease that is characterized by a defective skin barrier function. Recent studies have reported mutations of the skin barrier gene encoding filaggrin in a subset of patients with AD. OBJECTIVE: We investigated whether reduced filaggrin expression was found in patients with AD who were not carriers of known filaggrin mutations and whether filaggrin expression was modulated by the atopic inflammatory response. METHODS: Filaggrin expression was measured in skin biopsies and cultured keratinocytes using real-time RT-PCR and immunohistochemistry. Filaggrin loss-of-function mutations were screened in a total of 69 subjects. RESULTS: Compared with normal skin, filaggrin expression was significantly reduced (P < .05) in acute AD skin, with further reduction seen in acute lesions from 3 European American subjects with AD who were heterozygous for the 2282del4 mutation. This was confirmed by using immunohistochemistry. AD skin is characterized by the overexpression of IL-4 and IL-13. Keratinocytes differentiated in the presence of IL-4 and IL-13 exhibited significantly reduced filaggrin gene expression (0.04 +/- 0.01 ng filaggrin/ng glyceraldehyde 3-phosphate dehydrogenase; P < .05) compared with media alone (0.16 +/- 0.03). CONCLUSION: Patients with AD have an acquired defect in filaggrin expression that can be modulated by the atopic inflammatory response. CLINICAL IMPLICATIONS: The atopic immune response contributes to the skin barrier defect in AD; therefore, neutralization of IL-4 and IL-13 could improve skin barrier integrity.     

Diagnostic tests in children with atopic dermatitis and food allergy

Background Skin testing is a common diagnostic procedure in food allergy. The skin prick test is the test of first choice for investigating the immediate IgE-mediated reaction, TTie skin application food test (SAFT) has been developed on the basis of the mechanism of the contact urticaria syndrome (CUS), Methods We studied the relevance of the SAFT in children younger than 4 years with atopic dermatitis and (suspected) food allergy as compared with the prick-prick test, the radioallergosorbent test (RAST), and the oral challenge. In the skin tests, we used fresh food, in the same state as it was consumed.
Results There was a good agreement between the SAFT and the prick-prick test. A moderate agreement was observed between the SAFT and the serologic test (RAST). Significantly more positive results in the RAST were observed than in the SAFT, There was very good agreement between the SAFT and the oral challenge (K = 0,86).
Conclusions The SAFT is a reliable and child-friendly skin test for evaluating (suspected) food allergy in children younger than 4 years with atopic dermatitis. The very good correlation with the oral challenge indicates that one may probably consider the SAFT a "skin provocation" in children younger than 4 years.     

Duodenal IgE-positive cells and elimination diet responsiveness in children with atopic dermatitis.

BACKGROUND: Parameters for identifying eczematous children who could respond to an elimination diet are needed. In children with food allergy, duodenal IgE-containing cells are enhanced. OBJECTIVE: To determine the presence of duodenal mucosal IgE-positive cells in atopic dermatitis and to determine whether duodenal IgE-positive cells may identify eczematous children who will benefit from an elimination diet. METHODS: Thirty-one children with severe eczema underwent gastrointestinal endoscopy because of gastrointestinal symptoms and were treated with an elimination diet. A clinical score to skin lesions was given before and after diet. All subjects were skin-prick tested with food antigens and aeroallergens. Serum IgE levels were measured. Duodenal IgE-positive cells were investigated in 18 control subjects and in all eczematous children before diet. RESULTS: The number of duodenal IgE-positive cells in children with atopic dermatitis was significantly increased compared with that of control group (P < 0.001). Nineteen (61%) eczematous children improved on a few food diet. Diet-responsive children had significantly higher IgE-positive cells compared with both nondiet-responsive and controls. Positive predictive accuracy of duodenal IgE-positive cells was poor, whereas negative predictive accuracy was high at the cutoff level of 50 IgE-positive cells/10 visual fields. Diagnostic accuracy both of SPT reactions with foods and of food-specific serum IgE antibodies was poor. CONCLUSIONS: An intestinal IgE-mediated reaction occurred in children with severe atopic dermatitis who underwent intestinal endoscopy because of gastrointestinal symptoms. In these eczematous children, the number of IgE-positive cells in the duodenal mucosa might be helpful for excluding a positive response to the elimination diet.     

Food sensitization in infants and young children with atopic dermatitis

Atopic dermatitis (AD) is a chronic, relapsing, inflammatory skin disease. Children with AD tend to have a higher prevalence of food allergies. This study investigated the clinical significance of food sensitization in AD patients. A total of 266 AD patients participated in this study. The prevalence of food sensitization and clinically relevant sensitization were compared in the subjects according to their age and AD severity. Sera from all patients were analyzed for food-specific IgE levels using the Pharmacia CAP System FEIA. The serum specific IgE levels for egg, milk, peanut and soybean were measured. Patients were regarded as sensitized to the food if their food-specific IgE levels were above 0.35 kUA/L. Also the food-specific IgE levels, the so-called diagnostic decision point, which is recommended as the clinically relevant level, for clinical food allergy, as suggested by Sampson et al, was used as an alternative method. From the measurement of food-specific IgE antibodies of the four foods, egg was the most highly sensitized and the main causative allergenic food in children with AD. The positive rates of specific IgE to the four major food allergens, and the prevalences of clinically relevant food sensitization, were higher for all foods tested in the group less than 1 year of age, and were significantly higher in moderate to severe AD compared to mild AD in infants and young children. In summary, presence of food specific IgE is prevalent in infants and young children with AD, and clinically relevant food sensitization is important in Korean infants and children with moderate to severe AD.     

Experience with an elimination diet in children with atopic dermatitis

In order to define possible food-provoking factors, we placed twenty-nine children with chronic atopic dermatitis on an elimination diet. The children remained on their normal diet for 2 weeks followed by 2 weeks on the elimination diet. Foods were then re-introduced at the rate of a new one every 2 days in an attempt to identify foods exacerbating eczema. Thirteen children (45%) completed the elimination diet and seven of these were improved on parental assessment of sleeplessness, itchiness and area of eczema. Five were improved on the dermatologist's assessment. Only two children were able to identify foods provoking their eczema. Sixteen children (55%) failed to complete the elimination diet. Eight felt it was too strict, while eight did not return for follow-up. From our experience, dietary manipulation in older children with chronic atopic dermatitis offers only limited long-term therapeutic gains.     

Quality of life of children with atopic dermatitis and their families

PURPOSE OF THE REVIEW: Over the last few years major advances have been made in the conceptualization of quality of life and new instruments have been developed for assessing the construct in paediatric atopic dermatitis. This review looks at these developments and reports on recently published articles on the impact of the condition on affected children and other members of their family. RECENT FINDINGS: During the period of the review only one article addressing the impact of treatment for paediatric atopic dermatitis on quality of life could be found. This showed the benefits to the quality of life of parents of treating their children with pimecrolimus cream. SUMMARY: Given the prevalence of paediatric atopic dermatitis and its impact on affected children and their families it is surprising that so little attention has been devoted to the impact of treatment on quality of life. Where standardized measures are included in studies they generally assess outcomes that are of interest to physicians rather than to patients and their carers.