Update on the role of cytokines and chemokines in canine atopic dermatitis

BACKGROUND

Cytokines and chemokines play central roles in the pathogenesis of canine atopic dermatitis (cAD). Numerous studies have been published and provide new insights into their roles in cAD.

OBJECTIVES

To summarise the research updates on the role of cytokines and chemokines in the pathogenesis of cAD since the last review by the International Committee on Allergic Diseases of Animals in 2015.

MATERIAL AND METHODS

Online citation databases, abstracts and proceedings from international meetings on cytokines and chemokines relevant to cAD that had been published between 2015 and 2022 were reviewed.

RESULTS

Advances in technologies have allowed the simultaneous analysis of a broader range of cytokines and chemokines, which revealed an upregulation of a multipolar immunological axis (Th1, Th2, Th17 and Th22) in cAD. Most studies focused on specific cytokines, which were proposed as potential novel biomarkers and/or therapeutic targets for cAD, such as interleukin-31. Most other cytokines and chemokines had inconsistent results, perhaps as a consequence of their varied involvement in the pathogenesis of different endotypes of cAD.

CONCLUSIONS AND CLINICAL RELEVANCE

Inconsistent results for many cytokines and chemokines illustrate the difficulty of studying the complex cytokine and chemokine networks in cAD, and highlight the need for more comprehensive and structured studies in the future.

Skin repair and immunoregulatory effects of myeloid suppressor cells from human cord blood in atopic dermatitis

Introduction

Previously, we achieved large-scale expansion of bone marrow-derived suppressor cells (MDSCs) derived from cluster of differentiation (CD)34+ cells cultured in human umbilical cord blood (hUCB) and demonstrated their immunomodulatory properties. In the present study, we assessed the therapeutic efficacy of hUCB-MDSCs in atopic dermatitis (AD).

Methods

Dermatophagoides farinae (Df)-induced NC/Nga mice (clinical score of 7) were treated with hUCB-MDSCs or a control drug. The mechanisms underlying the therapeutic effects of hUCB-MDSCs were evaluated.

Results and discussion

hUCB-MDSCs demonstrated immunosuppressive effects in both human and mouse CD4+ T cells. hUCB-MDSCs significantly reduced the clinical severity scores, which were associated with histopathological changes, and reduced inflammatory cell infiltration, epidermal hyperplasia, and fibrosis. Furthermore, hUCB-MDSCs decreased the serum levels of immunoglobulin E, interleukin (IL)-4, IL-5, IL-13, IL-17, thymus- and activation-regulated chemokines, and thymic stromal lymphopoietin. Additionally, they altered the expression of the skin barrier function-related proteins filaggrin, involucrin, loricrin, cytokeratin 10, and cytokeratin 14 and suppressed the activation of Df-restimulated T-cells via cell-cell interactions. hUCB-MDSCs promoted skin recovery and maintained their therapeutic effect even after recurrence. Consequently, hUCB-MDSC administration improved Df-induced AD-like skin lesions and restored skin barrier function. Our findings support the potential of hUCB-MDSCs as a novel treatment strategy for AD.

Systemic treatments for atopic dermatitis (eczema): Systematic review and network meta-analysis of randomized trials

BACKGROUND

Atopic dermatitis (AD) is an inflammatory skin condition with multiple systemic treatments and uncertainty regarding their comparative impact on AD outcomes.

OBJECTIVE

We sought to systematically synthesize the benefits and harms of AD systemic treatments.

METHODS

For the 2023 American Academy of Allergy, Asthma & Immunology and American College of Allergy, Asthma, and Immunology Joint Task Force on Practice Parameters AD guidelines, we searched MEDLINE, EMBASE, CENTRAL, Web of Science, and GREAT databases from inception to November 29, 2022, for randomized trials addressing systemic treatments and phototherapy for AD. Paired reviewers independently screened records, extracted data, and assessed risk of bias. Random-effects network meta-analyses addressed AD severity, itch, sleep, AD-related quality of life, flares, and harms. The Grading of Recommendations Assessment, Development and Evaluation approach informed certainty of evidence ratings. This review is registered in the Open Science Framework (https://osf.io/e5sna).

RESULTS

The 149 included trials (28,686 patients with moderate-to-severe AD) evaluated 75 interventions. With high-certainty evidence, high-dose upadacitinib was among the most effective for 5 of 6 patient-important outcomes; high-dose abrocitinib and low-dose upadacitinib were among the most effective for 2 outcomes. These Janus kinase inhibitors were among the most harmful in increasing adverse events. With high-certainty evidence, dupilumab, lebrikizumab, and tralokinumab were of intermediate effectiveness and among the safest, modestly increasing conjunctivitis. Low-dose baricitinib was among the least effective. Efficacy and safety of azathioprine, oral corticosteroids, cyclosporine, methotrexate, mycophenolate, phototherapy, and many novel agents are less certain.

CONCLUSIONS

Among individuals with moderate-to-severe AD, high-certainty evidence demonstrates that high-dose upadacitinib is among the most effective in addressing multiple patient-important outcomes, but also is among the most harmful. High-dose abrocitinib and low-dose upadacitinib are effective, but also among the most harmful. Dupilumab, lebrikizumab, and tralokinumab are of intermediate effectiveness and have favorable safety.

Uptake of Staphylococcus aureus by keratinocytes is reduced by interferon-fibronectin pathway and filaggrin expression

Staphylococcus aureus (S. aureus) is frequently detected in the skin of patients with atopic dermatitis (AD). AD skin-derived strains of S. aureus (AD strain) are selectively internalized into keratinocytes (HaCaT cells) compared to standard strains. However, the mechanism of AD strain internalization by keratinocytes and effect of the skin environment on internalization remain unclear. HaCaT cells were exposed to heat-killed AD or standard strains of fluorescently labeled S. aureus, with or without interferon (IFN)-γ, interleukin (IL)-4, and IL-13 cytokines, for 24 h. Filaggrin and fibronectin expression in HaCaT cells was knocked down using small interfering RNA. The amount of internalized S. aureus was evaluated using a cell imaging system. The effects of INF-γ, IL-4, and S. aureus exposure on mRNA expression in HaCaT cells were analyzed using single-cell RNA sequencing. AD strains adhered to HaCaT cells in approximately 15 min and were increasingly internalized for up to 3 h (2361 ± 467 spots/100 cells, mean ± SD), whereas the standard strain was not (991 ± 71 spots/100 cells). In the presence of IFN-γ, both the number of internalized strains and fibronectin expression significantly decreased compared to in the control, whereas Th2 cytokines had no significant effects. The number of internalized AD strains was significantly higher in filaggrin knockdown and lower in fibronectin knockdown HaCaT cells compared to in the control. RNA sequencing revealed that IFN-γ decreased both fibronectin and filaggrin expression. Keratinocyte internalization of the AD strain may be predominantly mediated by the INF-γ-fibronectin pathway and partially regulated by filaggrin expression.

Effects of systemic therapies on pruritus in adults with atopic dermatitis: a systematic review and meta-analysis

Pruritus is a hallmark of atopic dermatitis (AD), affecting disease severity and patients' quality of life. In AD uncontrolled with first-line topical therapies or in moderate-to-severe AD, systemic therapies are used, however, there are paucity of head-to-head trials comparing their effectiveness. The aim was to compare the effectiveness between the systemic therapies on relieving pruritus in moderate-to-severe AD in adults through meta-analysis. PubMed, EMBASE, Medline and CINAHL databases were searched from inception up to 31 May 2020 for placebo-controlled randomised controlled trials investigating the effectiveness of systemic therapies on pruritus with moderate-to-severe AD in adults aged ≥ 16. 26 studies were identified (n = 5,190 participants). There was a large reduction in pruritus compared to placebo (standard mean difference [95% confidence interval]) with dupilumab every 2 weeks (q2w) (-0.88 [-1.13, -0.63]), q2w + topical corticosteroids (-0.77 [-0.91, -0.62]); dupilumab once weekly (qw) (-0.99 [-1.29, -0.68]), qw + topical corticosteroids (-0.70 [-0.81, -0.59]); a large reduction with ciclosporin (-1.30 [-2.34, -0.26]); a small reduction with mepolizumab (-0.27 [-0.89, 0.35]), interferon gamma (-0.31 [-0.75, 0.12]); a large reduction with azathioprine (-0.85 [-2.07, 0.35]). Amongst investigational drugs, nemolizumab 2.0mg/kg was the most effective (-8.13 [-9.31, -6.94]). The majority of systemic therapies were superior to placebo in reducing pruritus. In particular, dupilumab studies consistently showed large improvements in pruritus and nemolizumab showed the strongest anti-pruritic effects, however future head-to-head trials are required for conclusive evidence.

Systemic treatments in the management of atopic dermatitis: A systematic review and meta-analysis

BACKGROUND

As an evidence resource for the currently planned European Academy of Allergy and Clinical Immunology (EAACI) clinical practice guideline "systemic treatment of atopic dermatitis (AD)," we critically appraised evidence on systemic treatments for moderate-to-severe AD.

METHODS

We systematically identified randomized controlled trials (RCTs) investigating the safety and efficacy of systemic treatments for AD up to February 2020. Primary efficacy outcomes were clinical signs, AD symptoms and health-related quality of life. Primary safety outcomes included cumulative incidence rates for (serious) adverse events. Trial quality was assessed applying the Cochrane Risk of Bias Tool 2.0. Meta-analyses were conducted where appropriate.

RESULTS

50 RCTs totalling 6681 patients were included. Trial evidence was identified for apremilast, azathioprine (AZA), baricitinib, ciclosporin A (CSA), corticosteroids, dupilumab, interferon-gamma, intravenous immunoglobulins (IVIG), mepolizumab, methotrexate (MTX), omalizumab, upadacitinib and ustekinumab. Meta-analyses were indicated for the efficacy of baricitinib [EASI75 RD 0.16, 95% CI (0.10;0.23)] and dupilumab [EASI75, RD 0.37, 95% CI (0.32;0.42)] indicating short-term (ie 16-week treatment) superiority over placebo. Furthermore, efficacy analyses of AZA and CSA indicated short-term superiority over placebo; however, nonvalidated scores were used and can therefore not be compared to EASI.

CONCLUSION

The most robust, replicated high-quality trial evidence is present for the efficacy and safety of dupilumab for up to 1 year in adults. Robust trial evidence was further revealed for AZA, baricitinib and CSA. Methodological restrictions led to limited evidence-based conclusions for all other systemic treatments. Head-to-head trials with novel systemic treatments are required to clarify the future role of conventional therapies.

Systemic treatments for eczema: a network meta-analysis

BACKGROUND

Eczema is a common and chronic, relapsing, inflammatory skin disorder. It seriously impacts quality of life and economic outcomes, especially for those with moderate to severe eczema. Various treatments allow sustained control of the disease; however, their relative benefit remains unclear due to the limited number of trials directly comparing treatments.

OBJECTIVES

To assess the comparative efficacy and safety of different types of systemic immunosuppressive treatments for moderate to severe eczema using NMA and to generate rankings of available systemic immunosuppressive treatments for eczema according to their efficacy and safety.

SEARCH METHODS

We searched the following databases up to August 2019: the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, and Embase.

SELECTION CRITERIA

All randomised controlled trials (RCTs) of systemic immunosuppressive agents for moderate to severe atopic eczema when compared against placebo or any other eligible eczema treatment.

DATA COLLECTION AND ANALYSIS

We synthesised data using pair-wise analysis and NMA to compare treatments and rank them according to their effectiveness. Effectiveness was assessed primarily by determining the proportion of participants who achieved at least 75% improvement in the Eczema Area and Severity Index (EASI75) and improvement in the Patient-Oriented Eczema Measure (POEM). Safety was evaluated primarily by considering the proportion of participants with serious adverse events (SAEs) and infection. We deemed short-term follow-up as ≤ 16 weeks and long-term follow-up as > 16 weeks. We assessed the certainty of the body of evidence from the NMA for these primary outcomes using six domains of CiNEMA grading.

MAIN RESULTS

We included a total of 74 studies, with 8177 randomised participants. Approximately 55% of participants were male, with average age of 32 years (range 2 to 84 years), although age and gender were unreported for 419 and 902 participants, respectively. Most of the included trials were placebo controlled (65%), 34% were head-to-head studies (15% assessed the effects of different doses of the same drug), and 1% were multi-armed studies with both an active comparator and a placebo. All trials included participants with moderate to severe eczema, but 62% of studies did not separate data by severity; 38% of studies assessed only severe eczema. The total duration of included trials ranged from 2 weeks to 60 months, whereas treatment duration varied from a single dose (CIM331, KPL-716) to 60 months (methotrexate (MTX)). Seventy studies were available for quantitative synthesis; this review assessed 29 immunosuppressive agents from three classes of interventions. These included (1) conventional treatments, with ciclosporin assessed most commonly; (2) small molecule treatments, including phosphodiesterase (PDE)-4 inhibitors, tyrosine kinase inhibitors, and Janus kinase (JAK) inhibitors; and (3) biological treatments, including anti-CD31 receptors, anti-interleukin (IL)-22, anti-IL-31, anti-IL-13, anti-IL-12/23p40, anti-OX40, anti-TSLP, anti-CRTH2, and anti-immunoglobulin E (IgE) monoclonal antibodies, but most commonly dupilumab. Most trials (73) assessed outcomes at a short-term duration ranging from 2 to 16 weeks, whereas 33 trials assessed long-term outcomes, with duration ranging from 5 to 60 months. All participants were from a hospital setting. Fifty-two studies declared a source of funding, and of these, pharmaceutical companies funded 88%. We rated 37 studies as high risk; 21, unclear risk, and 16, low risk of bias, with studies most commonly at high risk of attrition bias. Network meta-analysis suggests that dupilumab ranks first for effectiveness when compared with other biological treatments. Dupilumab is more effective than placebo in achieving EASI75 (risk ratio (RR) 3.04, 95% confidence interval (CI) 2.51 to 3.69) and improvement in POEM score (mean difference 7.30, 95% CI 6.61 to 8.00) at short-term follow-up (high-certainty evidence). Very low-certainty evidence means we are uncertain of the effects of dupilumab when compared with placebo, in terms of the proportion of participants who achieve EASI75 (RR 2.59, 95% CI 1.87 to 3.60) at longer-term follow-up. Low-certainty evidence indicates that tralokinumab may be more effective than placebo in achieving short-term EASI75 (RR 2.54, 95% CI 1.21 to 5.34), but there was no evidence for tralokinumab to allow us to assess short-term follow-up of POEM or long-term follow-up of EASI75. We are uncertain of the effect of ustekinumab compared with placebo in achieving EASI75 (long-term follow-up: RR 1.17, 95% CI 0.40 to 3.45; short-term follow-up: RR 0.91, 95% CI 0.28 to 2.97; both very low certainty). We found no evidence on ustekinumab for the POEM outcome. We are uncertain whether other immunosuppressive agents that targeted our key outcomes influence the achievement of short-term EASI75 compared with placebo due to low- or very low-certainty evidence. Dupilumab and ustekinumab were the only immunosuppressive agents evaluated for longer-term EASI75. Dupilumab was the only agent evaluated for improvement in POEM during short-term follow-up. Low- to moderate-certainty evidence indicates a lower proportion of participants with SAEs after treatment with QAW039 and dupilumab compared to placebo during short-term follow-up, but low- to very low-certainty evidence suggests no difference in SAEs during short-term follow-up of other immunosuppressive agents compared to placebo. Evidence for effects of immunosuppressive agents on risk of any infection during short-term follow-up and SAEs during long-term follow-up compared with placebo was of low or very low certainty but did not indicate a difference. We did not identify differences in other adverse events (AEs), but dupilumab is associated with specific AEs, including eye inflammation and eosinophilia.

AUTHORS' CONCLUSIONS

Our findings indicate that dupilumab is the most effective biological treatment for eczema. Compared to placebo, dupilumab reduces eczema signs and symptoms in the short term for people with moderate to severe atopic eczema. Short-term safety outcomes from clinical trials did not reveal new safety concerns with dupilumab. Overall, evidence for the efficacy of most other immunosuppressive treatments for moderate to severe atopic eczema is of low or very low certainty. Given the lack of data comparing conventional with newer biological treatments for the primary outcomes, there remains high uncertainty for ranking the efficacy and safety of conventional treatments such as ciclosporin and biological treatments such as dupilumab. Most studies were placebo-controlled and assessed only short-term efficacy of immunosuppressive agents. Further adequately powered head-to-head RCTs should evaluate comparative long-term efficacy and safety of available treatments for moderate to severe eczema.

Managing atopic dermatitis with systemic therapies in adults and adolescents: An Australian/New Zealand narrative

With the rapid development of new, targeted therapies for the treatment of moderate/severe atopic dermatitis, it is opportune to review the available conventional systemic agents. We assess the published evidence for systemic therapies for atopic dermatitis and amalgamate this with real-world experience. Discussions are centred on when systemic therapy should be considered, which drug(s), what dose, how to sequence or combine these therapies, how long they should be continued for and what is considered success.

Relative efficacy of systemic treatments for atopic dermatitis

BACKGROUND

Systemic medications are often required for severe atopic dermatitis (AD) refractory to topical therapies. Biologic medications are a recent advancement in the field and a comparison with standard systemic approaches would be beneficial.

OBJECTIVE

To compare efficacies of systemic therapies for the treatment of AD.

METHODS

A systematic literature review was performed using Medline, Ovid, and Embase. Randomized controlled trials looking at the efficacy of systemic treatments for AD in adults and children were included.

RESULTS

A total of 41 studies met criteria and were included in our final analysis. Consistent improvements in Eczema Area and Severity Index and Scoring Atopic Dermatitis were reported with dupilumab and cyclosporine. Phase 2 clinical trials for lebrikizumab and tralokinumab were effective and would benefit from phase 3 trials. No study reported efficacy of biologic medications in pediatric patients; however, cyclosporine improved clinical severity by the greatest amount in this group.

LIMITATIONS

A lack of well controlled comparison studies make direct comparisons between the treatments difficult.

CONCLUSION

For treatment of severe AD, the strongest evidence currently exists for dupilumab and cyclosporine at improving clinical disease severity. Further research is required to determine long-term safety and efficacy of biologic medications.

The tolerogenic role of IFN-γ

Due to its extremely pleiotropic nature, the complex effects of IFN-γ exerted both on immune and non-immune cell types still remain only partially understood. The longstanding view of IFN-γ as being a predominantly inflammatory cytokine is constantly challenged by increasing demonstrations of its direct or indirect regulatory roles. Interferon-γ can exert tolerogenic effects on both innate and adaptive immune cell types, promoting tolerance of various antigen-presenting cells, and augmenting function and differentiation of regulatory T cells, respectively. Its capacity to induce IDO-competence is not limited to immune cells but extends to other cell types such as mesenchymal stem cells, epithelial cells, and tumors. The pro-inflammatory role of IFN-γ in tumor immune surveillance can backfire by directly inducing inhibitory molecule expression, such as PDL-1, on tumor cells. With increasing knowledge regarding the role of different helper T cell subsets in certain autoimmune diseases, the once contradictory observations of disease attenuation by IFN-γ can now be explained by its opposing interplay with other effector cytokines, particularly IL-17. The paradoxically immunosuppressive role of IFN-γ is also becoming evident in the transplantation setting, and graft-versus-host-disease. In the present review, we will discuss the latest findings that help to elucidate this dual role of IFN-γ at a cellular level, and in various pathophysiological states.

Treatment of Eczema: Corticosteroids and Beyond

Atopic dermatitis (AD) is a chronic inflammatory skin condition that requires a manifold approach to therapy. The goal of therapy is to restore the function of the epidermal barrier and to reduce skin inflammation. This can be achieved with skin moisturization and topical anti-inflammatory agents, such as topical corticosteroids and calcineurin inhibitors. Furthermore, proactive therapy with twice weekly use of both topical corticosteroids and calcineurin inhibitors in previously affected areas has been found to reduce the time to the next eczematous flare. Adjunctive treatment options include wet wrap therapy, anti-histamines, and vitamin D supplementation. Bacterial colonization, in particular Staphylococcus aureus, can contribute to eczematous flares and overt infection. Use of systemic antibiotics in infected lesions is warranted; however, empiric antibiotics use in uninfected lesions is controversial. Local antiseptic measures (i.e., bleach baths) and topical antimicrobial therapies can be considered in patients with high bacterial colonization. Difficult-to-treat AD is a complex clinical problem that may require re-evaluation of the initial diagnosis of AD, especially if the onset of disease occurs in adulthood. It may also necessitate evaluation for contact, food, and inhaled allergens that may exacerbate the underlying AD. There are a host of systemic therapies that have been successful in patients with difficult-to-treat AD, however, these agents are limited by their side effect profiles. Lastly, with further insight into the pathophysiology of AD, new biological agents have been investigated with promising results.

Reporting of symptoms in randomized controlled trials of atopic eczema treatments: a systematic review

'Symptoms' is a core outcome domain for atopic eczema (AE) trials, agreed by consensus as part of the Harmonising Outcome Measures for Eczema (HOME) initiative. To standardize and validate the core domain symptoms and symptom instruments for AE trials the HOME roadmap is followed. Its first step is to establish if and how symptoms have been measured in published AE treatment trials. Therefore the Global Resource for Eczema Trials database was used to collect all randomized controlled trials (RCTs) of treatments for AE between January 2000 and April 2014. Study selection and data extraction were performed by three reviewers independently. We identified the use of symptoms in 295 of 378 trials (78%). Symptoms as a primary end point were applied by 147 RCTs (50%). Seventeen different symptoms were measured, but mostly itch and sleep loss. Symptoms were assessed by only 37% of trials by a stand-alone symptom measurement. Overall 63% of RCTs used a composite instrument, and 30 different instruments were identified. The Scoring Atopic Dermatitis (SCORAD) index was the most commonly applied, but only 23% of RCTs reported the SCORAD symptom score separately. This systematic review demonstrates that symptoms, most frequently itch and sleep loss, are commonly reported in AE treatment trials, but are measured using many different instruments. Often symptoms are evaluated as part of a composite instrument, and currently it is not possible to extract symptoms-only data from most published studies. Future trials should report symptom scores to permit meta-analysis of the core outcomes.

Recent considerations in the use of recombinant interferon gamma for biological therapy of atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is the most common inflammatory skin disease in the general population. There are different endophenotypes of AD that likely have a unique immune and molecular basis, such as those who are predisposed to eczema herpeticum, or Staphylococcus aureus infections.

AREAS COVERED

In this review, we highlight the endophenotypes of AD where reduced interferon gamma expression may be playing a role. Additionally, we review the potential role of recombinant interferon gamma therapy in the treatment of atopic dermatitis and the particular phenotypes that may benefit from this treatment.

EXPERT OPINION

Recombinant interferon gamma treatment will likely benefit the pediatric population with AD, as well as those with susceptibilities for skin infections. Future studies are needed to elucidate whether IFN-γ may reduce the prevalence of skin infection in AD.

Systemic Agents for Severe Atopic Dermatitis in Children

Atopic dermatitis (AD), or eczema, is a chronic inflammatory skin condition characterized by relapsing pruritic, scaly, erythematous papules and plaques frequently associated with superinfection. The lifelong prevalence of AD is over 20 % in affluent countries. When a child with severe AD is not responding to optimized topical therapy including phototherapy, and relevant triggers cannot be identified or avoided, systemic therapy should be considered. If studies show early aggressive intervention can prevent one from advancing along the atopic march, and relevant triggers such as food allergies cannot be either identified or avoided, systemic therapy may also play a prophylactic role. Though the majority of evidence exists in adult populations, four systemic non-specific immunosuppressive or immunomodulatory drugs have demonstrated efficacy in AD and are used in most patients requiring this level of intervention regardless of age: cyclosporine, mycophenolate mofetil, methotrexate, and azathioprine. This article reviews the use of these medications as well as several promising targeted therapies currently in development including dupilumab and apremilast. We briefly cover several other systemic interventions that have been studied in children with atopic dermatitis.

The translational revolution and use of biologics in patients with inflammatory skin diseases

Psoriasis and atopic dermatitis (AD) are common inflammatory skin diseases characterized by immune-mediated inflammation and abnormal keratinocyte differentiation. Although T-cell infiltration characterizes both diseases, T-cell polarization differs. Psoriasis is currently the best model for translational medicine because many targeted therapeutics have been developed and testing of targeted therapeutics has cemented psoriasis as IL-23/TH17 polarized. In patients with AD, although therapeutic development is approximately a decade behind that in patients with psoriasis, there is now active development and testing of targeted therapeutics against various immune axes (TH2, TH22, and IL-23/TH17). These clinical trials and subsequent molecular analyses using human samples will be able to clarify the relative roles of polar cytokines in patients with AD.

Systemic therapy of childhood atopic dermatitis

Atopic dermatitis (AD) is a common childhood inflammatory disease that, in a small percentage of cases, can become severe enough to require potent systemic treatment. Many trials have been conducted with systemic agents for the treatment of severe pediatric AD; we review the evidence here. Although corticosteroids are widely used in practice, they are not generally recommended as a systemic treatment option for AD in children. Most patients experience a relatively rapid and robust response to cyclosporine. Treating children with cyclosporine long term is troubling; however, azathioprine, mycophenolate mofetil, and methotrexate are all reasonable alternatives for maintenance therapy in recalcitrant cases. Several additional options are available for the most refractory cases, including interferon-γ, intravenous immunoglobulin, and various biologics. Phototherapy is another modality that can be effective in treating severe AD. Ultimately the choice of agent is individualized. Systemic therapy options are associated with potentially severe adverse effects and require careful monitoring. Nonsystemic approaches toward prevention of flares and long-term control of atopic dermatitis in pediatric patients should be continued in conjunction with systemic therapy. In the future, more targeted systemic treatments hold the potential for effective control of disease with fewer side effects than broadly immunosuppressive agents.

Prevention of adverse events of interferon γ gene therapy by gene delivery of interferon γ-heparin-binding domain fusion protein in mice

Sustained gene delivery of interferon (IFN) γ can be an effective treatment, but our previous study showed high levels of IFNγ-induced adverse events, including the loss of body weight. These unwanted events could be reduced by target-specific delivery of IFNγ after in vivo gene transfer. To achieve this, we selected the heparin-binding domain (HBD) of extracellular superoxide dismutase as a molecule to anchor IFNγ to the cell surface. We designed three IFNγ derivatives, IFNγ-HBD₁, IFNγ-HBD₂, and IFNγ-HBD₃, each of which had 1, 2, or 3 HBDs, respectively. Each plasmid-encoding fusion proteins was delivered to the liver, a model target in this study, by hydrodynamic tail vein injection. The serum concentration of IFNγ-HBD₂ and IFNγ-HBD₃ after gene delivery was lower than that of IFNγ or IFNγ-HBD₁. Gene delivery of IFNγ-HBD₂, but not of IFNγ-HBD₃, effectively increased the mRNA expression of IFNγ-inducible genes in the liver, suggesting liver-specific distribution of IFNγ-HBD₂. Gene delivery of IFNγ-HBD₂-suppressed tumor growth in the liver as efficiently as that of IFNγ with much less symptoms of adverse effects. These results indicate that the adverse events of IFNγ gene transfer can be prevented by gene delivery of IFNγ-HBD₂, a fusion protein with high cell surface affinity.

Guidelines of care for the management of atopic dermatitis: section 3. Management and treatment with phototherapy and systemic agents

Atopic dermatitis is a chronic, pruritic inflammatory dermatosis that affects up to 25% of children and 2% to 3% of adults. This guideline addresses important clinical questions that arise in atopic dermatitis management and care, providing recommendations based on the available evidence. In this third of 4 sections, treatment of atopic dermatitis with phototherapy and systemic immunomodulators, antimicrobials, and antihistamines is reviewed, including indications for use and the risk-benefit profile of each treatment option.

[Control of spatiotemporal distribution of interferon γ by genetically fusing functional peptides]

Type II interferon (IFNγ) is a representative Th1 cytokine and it possesses a variety of functions, including immune regulation, antiviral and antitumor activity. Because of its multifunctional nature, IFNγ is expected to be applied to the treatment of autoimmune diseases, cancer and viral infection. Although IFNγ has therapeutic potential for such diseases, the clinical use of IFNγ has been limited due to its short in vivo half-life and serious adverse effects. In contrast, gene delivery of IFNγ is an alternative approach to increasing the retention time of IFNγ. To extend transgene expression after plasmid DNA (pDNA) gene transfer, we designed and developed pDNA with varying numbers of CpG motifs. CpG-reduced pDNA resulted in more durable transgene expression than its CpG replete counterpart in mice. Comparison of the effect of promoter/enhancer elements on transgene expression showed that ROSA26 promoter-mediated IFNγ expression was safe because of the lack of an initial surge after hydrodynamic gene transfer. We also designed an IFNγ-mouse serum albumin (MSA) fusion protein, IFNγ-MSA. Gene transfer of this fusion protein resulted in a sustained concentration of IFNγ fusion protein in mouse serum, and inhibited tumor metastasis in mice. These results provide experimental evidence that IFNγ gene therapy can be a useful treatment for a variety of diseases.

The effects of treatment on itch in atopic dermatitis

Pruritus causes significant impairment in the quality of life of patients suffering from atopic dermatitis. Treatments for itch in atopic dermatitis range from simple avoidance of pruritus triggers to more complicated systemic therapy. Several treatments aim to target specific mediators of itch in atopic dermatitis, whereas others improve pruritus by reducing inflammation. Currently the most effective treatments for atopic dermatitis-associated itch are primarily topical or systemic anti-inflammatory agents. Better management of pruritus in atopic dermatitis is an important goal and necessitates the development of novel targeted treatments as well as efficient use of current therapies.

Immunology of atopic eczema: overcoming the Th1/Th2 paradigm

Atopic eczema (AE) is a challenge for modern medicine, because it is prevalent, severely affects quality of life of patients and their families, and causes high socioeconomic costs. The pathogenesis of AE is complex. While initial studies suggested a Th2 deviation as primary reason for the disease, numerous studies addressed a genetically predetermined impaired epidermal barrier as leading cause in a subgroup of patients. Recently, immune changes beyond the initial Th2 concept were defined in AE, with a role for specialized dendritic cells as well as newly identified T helper cell subsets such as Th17 and Th22 cells. Furthermore, trigger factors are expanded beyond classical Th2 allergens such as pollen or house dust mites to microbial products as well as self-antigens. This review pieces together our current understanding of immune as well as barrier abnormalities into the pathogenesis mosaic of AE.

Biologics in dermatology

Skin and subcutaneous diseases affect millions of people worldwide, causing significant morbidity. Biologics are becoming increasingly useful for the treatment of many skin diseases, particularly as alternatives for patients who have failed to tolerate or respond to conventional systemic therapies. Biological therapies provide a targeted approach to treatment through interaction with specific components of the underlying immune and inflammatory disease processes. This review article examines the increasing evidence base for biologics in dermatology, including well-established treatments and novel agents.

New era of biologic therapeutics in atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a common inflammatory skin disease regulated by genetic and environmental factors. Both skin barrier defects and aberrant immune responses are believed to drive cutaneous inflammation in AD. Existing therapies rely largely on allergen avoidance, emollients and topical and systemic immune-suppressants, some with significant toxicity and transient efficacy; no specific targeted therapies are in clinical use today. As our specific understanding of the immune and molecular pathways that cause different subsets of AD increases, a variety of experimental agents, particularly biologic agents that target pathogenic molecules bring the promise of safe and effective therapeutics for long-term use.

AREAS COVERED

This paper discusses the molecular pathways characterizing AD, the contributions of barrier and immune abnormalities to its pathogenesis, and development of new treatments that target key molecules in these pathways. In this review, we will discuss a variety of biologic therapies that are in development or in clinical trials for AD, perhaps revolutionizing treatment of this disease.

EXPERT OPINION

Biologic agents in moderate to severe AD offer promise for controlling a disease that currently lacks good and safe therapeutics posing a large unmet need. Unfortunately, existing treatments for AD aim to decrease cutaneous inflammation, but are not specific for the pathways driving this disease. An increasing understanding of the immune mechanisms underlying AD brings the promise of narrow targeted therapies as has occurred for psoriasis, another inflammatory skin disease, for which specific biologic agents have been demonstrated to both control the disease and prevent occurrence of new skin lesions. Although no biologic is yet approved for AD, these are exciting times for active therapeutic development in AD that might lead to revolutionary therapeutics for this disease.

Regulation of immunological balance by sustained interferon-γ gene transfer for acute phase of atopic dermatitis in mice

Interferon (IFN)-γ, a potent T helper 1 (Th1) cell cytokine, is suggested to suppress Th2 cell responses. Here, we aimed to investigate whether pCpG-Muγ, a plasmid continuously expressing murine IFN-γ, is an effective treatment of atopic dermatitis, a Th2-dominant skin disease. Nishiki-nezumi Cinnamon/Nagoya (NC/Nga) atopic mice with early dermatitis were transfected with pCpG-Muγ by a hydrodynamic tail vein injection at a dose of 0.05 or 0.2 pmol per mouse. The skin lesions improved only in mice receiving the high dose of pCpG-Muγ. IFN-γ gene transfer resulted in a high mRNA expression of IFN-γ and interleukin (IL)-12 and regulatory T cell (Treg) related cytokines, such as IL-10 and transforming growth factor-β, in the spleen, whereas it reduced the IL-4 mRNA expression, and serum levels of immunoglobulin (Ig) G1 and IgE. In addition, the gene transfer markedly inhibited the epidermal thickening, infiltration of inflammatory cells into the skin, the occurrence of dry skin and pruritus. No exacerbating effect on the Th1-mediated contact dermatitis was observed after IFN-γ gene transfer. Taken together, these results indicate that sustained IFN-γ gene transfer induced polarized Th1 immunity under Th2-dominant conditions in NC/Nga mice, leading to an improvement in the symptoms of acute atopic dermatitis without adverse side effects.

Guidelines for treatment of atopic eczema (atopic dermatitis) Part II

The existing evidence for treatment of atopic eczema (atopic dermatitis, AE) is evaluated using the national standard Appraisal of Guidelines Research and Evaluation. The consensus process consisted of a nominal group process and a DELPHI procedure. Management of AE must consider the individual symptomatic variability of the disease. Basic therapy is focused on hydrating topical treatment, and avoidance of specific and unspecific provocation factors. Anti-inflammatory treatment based on topical glucocorticosteroids and topical calcineurin inhibitors (TCI) is used for exacerbation management and more recently for proactive therapy in selected cases. Topical corticosteroids remain the mainstay of therapy, but the TCI tacrolimus and pimecrolimus are preferred in certain locations. Systemic immune-suppressive treatment is an option for severe refractory cases. Microbial colonization and superinfection may induce disease exacerbation and can justify additional antimicrobial treatment. Adjuvant therapy includes UV irradiation preferably with UVA1 wavelength or UVB 311 nm. Dietary recommendations should be specific and given only in diagnosed individual food allergy. Allergen-specific immunotherapy to aeroallergens may be useful in selected cases. Stress-induced exacerbations may make psychosomatic counselling recommendable. 'Eczema school' educational programs have been proven to be helpful. Pruritus is targeted with the majority of the recommended therapies, but some patients need additional antipruritic therapies.

Contrasting pathogenesis of atopic dermatitis and psoriasis--part I: clinical and pathologic concepts

Atopic dermatitis and psoriasis are 2 of the most common inflammatory skin diseases. They are similar in that they are complex inherited diseases involving genes that encode immune components and structural proteins that regulate differentiation of epidermal cells. Each disease is characterized by proliferation of epidermal keratinocytes and abnormal cornification or terminal differentiation in the epidermis; skin lesions contain immune infiltrates of T cells, dendritic cells, and other types of leukocytes. We review similarities between the diseases and differences in epidermal barrier defects and immune cells. We also propose mechanisms of pathogenesis based on differences in the balance of immune cell subsets that could cause the phenotypes that distinguish these diseases. The first part of this 2-part review focuses on the clinical and pathologic features of the diseases; the second part discusses differences in immune cell subsets between atopic dermatitis and psoriasis and recent therapeutic strategies.

Pathophysiology and therapy of pruritus in allergic and atopic diseases

Pruritus (itch) is a major characteristic and one of the most debilitating symptoms in allergic and atopic diseases and the diagnostic hallmark of atopic dermatitis. Pruritus is regularly defined as an unpleasant sensation provoking the desire to scratch. Although we achieved rather good knowledge about certain inducers of itch such as neuropeptides, amines, mu-opioids, cytokines and proteases, for example, less is known about the pathophysiological specifities among the different diseases, and the therapeutic consequences which may derive thereoff. This review dissects the role of mediators, receptors and itch inhibitors on peripheral nerve endings, dorsal root ganglia, the spinal cord and the CNS leading to the amplification or - vice versa - suppression of pruritus. As the treatment of pruritus in allergic and atopic skin disease is still not satisfactory, knowing these pathways and mechanisms may lead to novel therapeutic approaches against this frequently encountered skin symptom.

Sustained exogenous expression of therapeutic levels of IFN-gamma ameliorates atopic dermatitis in NC/Nga mice via Th1 polarization

The short in vivo half-life of IFN-gamma can prevent the cytokine from inducing immunological changes that are favorable for the treatment of Th2-dominant diseases, such as atopic dermatitis. To examine whether a sustained supply of IFN-gamma is effective in regulating the balance of Th lymphocyte subpopulations, plasmid vector encoding mouse IFN-gamma, pCpG-Mugamma, or pCMV-Mugamma was injected into the tail vein of NC/Nga mice, a model for human atopic dermatitis. A single hydrodynamic injection of a CpG motif reduced pCpG-Mugamma at a dose of 0.14 microg/mouse resulted in a sustained concentration of IFN-gamma in the serum, and the concentration was maintained at >300 pg/ml over 80 d. The pCpG-Mugamma-mediated IFN-gamma gene transfer was associated with an increase in the serum concentration of IL-12, reduced production of IgE, and inhibition of mRNA expression of IL-4, -5, -10, -13, and -17 and thymus and activation-regulated chemokine in the spleen. These immunological changes were not clearly observed in mice receiving two injections of 20 microg pCMV-Mugamma, a CpG-replete plasmid DNA, because of the transient nature of the expression from the vector. The mice receiving pCpG-Mugamma showed a significant reduction in the severity of skin lesions and in the intensity of their scratching behavior. Furthermore, high transepidermal water loss, epidermal thickening, and infiltration of lymphocytes and eosinophils, all of which were obvious in the untreated mice, were significantly inhibited. These results indicate that an extraordinary sustained IFN-gamma expression induces favorable immunological changes, leading to a Th1-dominant state in the atopic dermatitis model.

Systemic therapy of atopic dermatitis in children

Atopic dermatitis (AD) is a common disease in childhood that is a serious burden on patients and their families. Most AD is mild and can be managed with the use of emollients and standard therapy consisting of topical corticosteroids or topical calcineurin inhibitors. However, in a subgroup of patients with moderate to severe AD, the disease is recalcitrant to topical therapy and systemic treatments become necessary. Short courses of systemic corticosteroids are often used in clinical practice, but their use is controversial. International guidelines suggest that in the case of acute flare-ups, patients might benefit from a short course of systemic corticosteroids, but long-term use and use in children should be avoided. Ciclosporin is an immunosuppressant agent that acts directly on cells of the immune system, with an inhibitory effect on T cells. When AD cannot be controlled by standard topical therapies, ciclosporin significantly decreases symptom scores, disease extent, pruritus and sleep deprivation, and improves quality of life. The most frequent adverse effects associated with the use of ciclosporin are hypertension and renal dysfunction, but they are usually reversible after drug discontinuation. Ciclosporin has been found to be safely used, effective and well tolerated in children with severe AD. However, studies to assess the long-term effectiveness and safety of ciclosporin in AD are lacking. In patients for whom ciclosporin is not suitable, or when there is a lack of response, alternative drugs should be considered, such as azathioprine or interferon-gamma. Intravenous immunoglobulins and the monoclonal antibody infliximab only have a place in the systemic therapy of AD when other drugs have failed. Mycophenolate mofetil has recently been introduced in the treatment of recalcitrant AD. Efalizumab and omalizumab are monoclonal antibodies with a possible future role in the treatment of AD, but further studies are needed.

The comparative effects of tacrolimus and hydrocortisone in adult atopic dermatitis: an immunohistochemical study

BACKGROUND

While many studies have demonstrated the efficacy and safety of tacrolimus ointment in the treatment of atopic dermatitis (AD), only a few have investigated the effects of tacrolimus on inflammatory cells and their cytokine gene expression in patients with AD.

OBJECTIVES

To characterize further the immunophenotype of infiltrating cells and the production of certain cytokines before and after treatment with topical tacrolimus and hydrocortisone butyrate.

METHODS

Nine adult patients with moderate to severe AD were treated with tacrolimus ointment, while seven control patients were treated with hydrocortisone butyrate ointment. We performed lesional skin biopsies before and after treatment. These were stained immunohistochemically with a panel of monoclonal antibodies including those to CD1a, CD3, CD4, CD8, myeloperoxidase, EG1, EG2, tryptase, interferon-gamma, interleukin (IL)-4, IL-5, IL-12, IL-13, receptors for CXC chemokines (CXCR) 3 and 4, and receptor 3 for CC chemokines.

RESULTS

CD3+, CD4+ and CD8+ lymphocytes, and eosinophil and neutrophil granulocytes were significantly reduced in post-treatment tacrolimus specimens, while CD1a+ cells and mast cells were not. The expression of cytokines and chemokine receptors tested, except for CXCR3, was diminished by tacrolimus treatment. Moreover, tacrolimus produced a greater reduction of lymphocytes, eosinophils and most cytokines than that induced by hydrocortisone butyrate.

CONCLUSIONS

Tacrolimus not only inhibits T-lymphocyte proliferation and cytokine production, but also plays an important role in the IL-12-induced shift from a T-helper (Th) 2 to a Th1 cytokine profile that characterizes the development of chronic AD. Tacrolimus also demonstrates wider pharmacodynamic effects than hydrocortisone.

A randomized comparative clinical trial of recombinant canine interferon-gamma (KT-100) in atopic dogs using antihistamine as control

Recombinant canine interferon-gamma (KT-100) or topical antihistamine (diphenhydramine: DH) was administered to dogs with atopic dermatitis (AD) for 4 weeks and their efficacies were compared using pruritus, excoriation, erythema and alopecia as evaluation criteria. Clinical studies on 92 atopic dogs (KT-100 group: 63, DH group: 29) were conducted at 18 animal hospitals in Japan. KT-100 was administered subcutaneously once a day three times a week on alternating days for 4 weeks. DH was administered topically twice daily for 4 weeks. The efficacy rates of the KT-100 group on day 28 were 72.1% for pruritus, 73.8% for excoriation, 75.4% for erythema and 60.7% for alopecia, which were significantly higher than those of the DH group (20.7% for pruritus, 27.6% for excoriation, 24.1% for erythema and 24.1% for alopecia).

Recent developments in the treatment of adult atopic dermatitis

Atopic dermatitis is a common inflammatory skin condition with increasing incidence in recent decades. The mainstay of treatment has been the combination of emollients and topical corticosteroids, with the addition of systemic therapies in severe cases. New drugs such as the topical calcineurin inhibitors have shown promise in treating mild-to-severe atopic dermatitis. Other novel therapies that have been reported in the literature include leukotriene antagonists, monoclonal antibodies such as infliximab, leflunomide, recombinant interferon gamma and intravenous immunoglobulin. This review will focus on the treatment of adult atopic dermatitis.

Cytokine and Anti-Cytokine Therapies for Psoriasis and Atopic Dermatitis

Since the discovery of cytokines as key mediators in inflammation, targeting the cytokine network has represented a promising therapeutic approach. Psoriasis and atopic dermatitis, as T cell-mediated diseases with a strong cytokine component and a high unmet medical need, have moved into the focus of experimental therapies. Whereas pro-inflammatory cytokines such as tumor necrosis factor (TNF)-alpha are overexpressed in both diseases, a type 1 cytokine pattern predominates in psoriasis and a type 2 cytokine pattern is of pathophysiological importance at least in the initial stages of atopic dermatitis. Strategies for intervention into the cytokine network have included antagonism of pro-inflammatory cytokines (e.g. TNFalpha, interleukin [IL]-1, IL-8, IL-12, IL-18, IL-23) with neutralizing antibodies and soluble receptors, application of recombinant cytokines (e.g. IL-4, IL-10, IL-11, interferon [IFN]-gamma) to shift the cytokine balance, and administration of small molecules to modulate cytokine expression or signaling. Results from the clinic have led to novel therapeutic options as well as a better understanding of the pathophysiology of inflammatory skin diseases. This review highlights the various therapeutic strategies, results from the clinic (that are in some cases preliminary), and insights that can be drawn from the more advanced clinical studies and the use of approved cytokine-directed therapies.

The potential role of allergen-specific sublingual immunotherapy in atopic dermatitis

Atopic dermatitis is a chronic inflammatory skin disease associated with increasing prevalence, morbidity, and cost in developed Western countries. Frequently associated with respiratory allergy during adulthood, atopic dermatitis often represents the first phenotypic appearance of atopy in early childhood when the allergic 'march' starts and progressively moves toward food allergy, asthma, and rhinitis. At present, a consistent body of evidence supports the view that atopic dermatitis may represent the skin compartmentalization of a systemic allergic inflammation. Lymphocytes infiltrating early lesional skin express a T helper (Th) 2 pattern of cytokine secretion (increased levels of interleukin [IL]-4 and/or IL-13 and decreased levels of interferon-gamma) as well as the typical Th2-type chemokine receptor CCR4, specific to the thymus and activation-regulated chemokines. Keratinocytes from patients with atopic dermatitis produce thymic stromal lymphopoietin, a novel cytokine that supports the early lymphocyte development in mouse models, and activates dendritic cells involved in the pathogenesis of allergic diseases in humans. Increased levels of circulating hemopoietic precursor cells have been reported in atopic dermatitis, as in allergic asthma and rhinitis. Furthermore, the recognition of CD34+ hemopoietic precursor cells, and evidence for cellular differentiation/maturational events occurring within atopic dermatitis skin lesion infiltrates, are consistent with the recent reinterpretation of the Th2/Th1 paradigm, where Th2 cells appear to belong to the early stages and Th1 to the ultimate stages of a linear, rather than divergent, pattern of lymphoid differentiation. This more detailed understanding of the immunologic derangements contributing to the atopic dermatitis pathogenesis has led to growing interest in allergen-specific immunotherapy for the disease. Due to the complexity intrinsic to atopic dermatitis and the lack of consensus-based guidelines for standardized outcome measure, only eight studies are available in the literature for a qualitative evaluation of this treatment approach. Two of these studies were double blind and placebo controlled, and six were cohort studies. Immunotherapy was found to be effective in one controlled study and five observational reports. Uncertain results were provided by one low-powered, controlled study, and negative outcomes were raised by a unique study performed with oral immunotherapy, which is not an effective route of mucosal allergen administration. Thus, more efficacy studies are required before immunotherapy could be recommended for the routine treatment of atopic dermatitis. Allergen-specific sublingual immunotherapy, given its excellent safety profile and ability to interfere with the systemic aspects of allergic inflammation, appears a good potential candidate for the pathogenetic treatment of the disease.

Measuring atopic dermatitis severity in randomized controlled clinical trials: what exactly are we measuring?

Well-designed clinical trials are a fundamental aspect of evidence-based medicine. Such trials are dependent on the use of valid, reliable, and relevant outcome measures. Wide variation in outcome methodology can have important detrimental effects on the correct interpretation and comparison of results. The objective of this study was to describe the variation in outcome methodology in randomized controlled trials of therapeutic interventions for atopic dermatitis published between January 1994 and December 2001. Of the 93 eligible randomized controlled trials identified using a systematic electronic database search strategy, 85 (91%) incorporated an objective measurement of clinical signs. Only 23 (27%) of these trials used a published severity scale, however. The remainder used either modified versions of published scales (14%) or unnamed scales with no data on validity or reliability (59%), although unpublished scales were used significantly less frequently over the last 2 y compared to previously (21%vs 74%, p<0.01). There was lack of consensus on which clinical features best reflect disease severity, with 31 different descriptions of clinical signs being used across all scoring systems. Fifty-six different "objective" clinical scales were identified. Patient symptoms were recorded in 80 trials (86%) and disease extent in 62 trials (67%). Quality of life was measured in only three trials (3%). This wide variation in outcome methodology is hindering evidence-based practice, and the widespread use of unvalidated outcome measures is a potential source of bias and inaccuracy. More emphasis should be placed on measuring things that are important to patients such as symptoms and quality of life.

Cost of illness of atopic dermatitis in children: a societal perspective

Childhood atopic dermatitis is a disorder with considerable social and financial costs. Consideration of these costs is increasingly important in view of the growing prevalence of atopic dermatitis, particularly in developed countries over recent decades. The family stress related to the care of children with moderate or severe atopic dermatitis is significantly greater than that of the care of children with type 1 diabetes mellitus. The factors contributing to family stress include sleep deprivation, loss of employment, time taken for care of atopic dermatitis and financial costs. The financial costs for the family and community include medical and hospital direct costs of treatments and indirect costs from loss of employment. There are many interventions utilised in the treatment of childhood atopic dermatitis which involve not only medical practitioners but nurses, pharmacists, dieticians, psychologists and purveyors of so-called alternative therapies such as naturopathy, aromatherapy and bioresonance, all of which contribute to the financial burdens on the parents and the community. It is possible that appropriate interventions directed to reducing trigger factors might produce worthwhile savings, although the cost benefit of these measures has not been demonstrated. In conclusion, atopic dermatitis should not be regarded as a minor skin disorder but as a condition which has the potential to be a major handicap with considerable personal, social and financial consequences both to the family and the community.