Features of childhood atopic dermatitis

Eczema or atopic dermatitis (AD) is the most common skin disease in children, and recent data derived from several studies showed that the prevalence of AD is still increasing in most Asian countries. The role of allergic reactions in AD is still a matter of debate. In some children allergy is not involved, while in others allergic reactions can trigger and maintain the skin lesions. Therefore, AD is now considered as a group of skin diseases with as a common feature the existence of a chronic skin inflammation. The underlying mechanisms of AD are not uniform, but differ from patient to patient, and also differ in one patient in time, suggesting the existence of different subtypes of AD, in a complex interplay. From different studies it is now suggested that at least 4 different players are involved in AD. These 4 players are: congenital skin barrier defects, allergy, autoimmunity (i.e. the production of autoantibodies against skin cells), and microbial agent colonization, especially colonization with bacteria, mainly Staphylococcus aureus. Much more needs to be discovered on the mechanisms of AD and other "players" might be discovered soon, as the current "4-player-model" cannot explain all features of AD. Treatment of AD might change in the near future. Today's cornerstones of treatment are still moisturizers (from a young age to prevent further skin barrier dysfunctions and allergic sensitization), local corticosteroids, and antiseptics, but new future therapeutic approaches become very likely.     

Filaggrin null mutations in childhood atopic dermatitis among the Chinese

Atopic dermatitis (AD) is associated with loss or reduced expression of filaggrin (FLG). We evaluated five FLG null mutations, namely R501X, 2282del4, R2447X, S2554X, and S2889X, in 174 Chinese children with AD and 191 matched controls. 2282del4, R2447X, S2554X and S2889X mutations were not found in these patients. Heterozygous carriage of R501X was only found in four male patients, and associated with long‐term disease severity. FLG mutations prevalent in Caucasian and other Asian populations are rarely found in our series.     

A pilot study to explore the usefulness of antibody array in childhood atopic dermatitis

BACKGROUND: The pathophysiology of childhood atopic dermatitis (AD) involves complex interactions among cellular, humoral, cytokine and chemokine systems. Objective: To evaluate protein expressions using antibody microarray. METHODS: Severity-nine proteins were assayed using antibody microarray on AD patients age < 18 years. Disease severity was assessed with the SCORing Atopic Dermatitis (SCORAD) and Nottingham Eczema Severity Score (NESS), and quality of life with the Children Dermatology Life Quality Index (CDLQI). Serum IgE levels were also assessed. Normal subjects without atopy were used as controls. Cytokines, chemokines and a wide array of proteins were assayed with RayBio Human Cytokine Antibody Array V (RayBiotech, Norcross, GA). RESULTS: Nine Chinese children with AD and four normal subjects were recruited. The median SCORAD was 60.7. Among the 79 proteins, the levels of BDNF, Fit-3 ligand, IL-8, IL-16, LIGHT, MIP-1beta, MIP-3alpha, NAP-2, PARC, TGF-beta2 and TIMP-2 were significantly different from the controls. Nevertheless, no significance was found when adjusted for multiple comparisons using p = 0.0006. Some of these markers showed significant correlations with various components of SCORAD, NESS and CDLQI. The serum IgE level as a marker of atopy correlates significantly with BDNF, LIGHT, PARC and TIMP-2. CONCLUSIONS: The serum levels of BDNF, LIGHT, PARC and TIMP-2 correlate to IgE as a marker of atopy. Although targeting chemokines and chemokine receptors may offer new opportunities for therapeutic interventions in AD, protein assay with cytokine antibody array was generally not helpful in identifying specific molecules pertinent to AD activity.     

Milk allergy/intolerance and atopic dermatitis in infancy and childhood

Adverse reactions to cow's milk proteins are usually indicated as cow's milk allergy/intolerance (CMPA/CMPI) because no differentiation is possible on the basis of symptoms, and there is no reliable single laboratory test available for the diagnosis of CMPA or CMPI. Elimination and challenge tests for cow's milk proteins using strict, well-defined diagnostic criteria are required for the diagnosis of CMPA/CMPI. Atopic dermatitis (AD) is one of the most common symptoms of CMPA/CMPI. Approximately one third of AD children have a diagnosis of CMPA/CMPI according to elimination diet and challenge tests, and about 40–50% of children <1 year of age with CMPA/CMPI have AD. Many children with AD and CMPA/CMPI develop a complete tolerance to CMP in a few years. Children with persisting forms of CMPA/CMPI have a more frequent history of familial atopic disease, change in CMPA/CMPI manifestations over time and very high frequency of multiple food intolerance and allergic diseases. Many children who outgrow their AD develop other allergic diseases, such as rhinitis or asthma. The simultaneous development of allergic tolerance in one organ and the intolerance or atopic disease in another organ suggest that genetic, immunologic and environmental factors play a complex role in the natural history of AD and other atopic diseases.     

Interleukin 2 therapy in severe atopic dermatitis

Interleukin 2 (IL-2) at a dose of 10,000 to 20,000 U/kg/q 8 hr was given for 9–12 days to six patients with cases of severe atopic dermatitis (AD) which were refractory to conventional therapy. After IL-2 therapy, the clinical symptoms and signs of eczema including pruritus, scratching, papulovesicles, and lichenification were much improved, but all of them recurred 2–6 weeks after stopping treatment. Adverse reactions were similar to those reported previously, but all of them subsided after discontinuation of therapy. Laboratory findings showed decreased T-cell subsets, especially CD4+ cells, and increased IL-2R+ (CD25) cells, but there was no significant change in serum IL-2, serum IgE, orin vitro IgE production. Immunopathological studies of the skin biopsies showed decreased mononuclear-cell infiltration, depletion of CD4+ cells, and enhanced expression of CD25 and HLA-DR antigens. As lymphokine-activated killer (LAK)-cell activity against cultured fibroblasts was similar in patients with AD and in normals and CD1+ Langerhans cells were not decreased after IL-2 therapy, we speculate that the depletion of helper/inducer CD4+ cells and hence abrogation of the exaggerated antigen processing and cellular activation in diseased skin are the explanation for the transient efficacy of IL-2 in the treatment of atopic dermatitis.     

Dietary treatment of childhood atopic eczema/dermatitis syndrome (AEDS)

Objective:  This review summarizes the research and clinical evidence in favour of dietary intervention aimed at eliminating allergenic foods in the management of atopic eczema/dermatitis syndrome (AEDS).
Data sources:  The data source was PubMed, using a search algorithm selecting for clinical studies of AEDS, diet therapy and food allergy in all children to October 2003. Also included is a commentary based on the authors' clinical experience in the allergy unit of a university hospital in Italy.
Results:  Fourteen prospective studies matched the entry criteria. Diverse trial designs, diagnostic criteria, types of dietary intervention and length of observation periods precluded meta-analytic methods. Allergenic food exclusion claimed efficacy in 13 of the 14 studies and was most useful in infants, in patients with elevated immunoglobulin E levels and/or multiple food sensitization and in patients with a diagnosis of food allergy.
Conclusion:  Dietary intervention in the form of an elimination diet is efficacious in children with AEDS when a specific diagnosis of food allergy has been made. Diagnostic evaluation of food allergy should be performed in all children with eczema, particularly in younger children and those with severe forms of the disease.     

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.