Search

Background: Loss-of-function null mutations R501X and 2282del4 in the skin barrier gene, filaggrin (FLG), represent the most replicated genetic risk factors for atopic dermatitis (AD). Associations have not been reported in African ancestry populations. Atopic dermatitis eczema herpeticum (ADEH) is a rare but serious complication of AD resulting from disseminated cutaneous herpes simplex virus infections., Objective: We aimed to determine whether FLG polymorphisms contribute to ADEH susceptibility., Methods: Two common loss-of-function mutations plus 9 FLG single nucleotide polymorphisms were genotyped in 278 European American patients with AD, of whom 112 had ADEH, and 157 nonatopic controls. Replication was performed on 339 African American subjects., Results: Significant associations were observed for both the R501X and 2282del4 mutations and AD among European American subjects (P = 1.46 x 10(-5), 3.87 x 10(-5), respectively), but the frequency of the R501X mutation was 3 times higher (25% vs 9%) for ADEH than for AD without eczema herpeticum (EH) (odds ratio [OR], 3.4; 1.7-6.8; P = .0002). Associations with ADEH were stronger with the combined null mutations (OR, 10.1; 4.7-22.1; P = 1.99 x 10(-11)). Associations with the R501X mutation were replicated in the African American population; the null mutation was absent among healthy African American subjects, but present among patients with AD (3.2%; P = .035) and common among patients with ADEH (9.4%; P = .0049). However, the 2282del4 mutation was absent among African American patients with ADEH and rare (<1%) among healthy individuals., Conclusion: The R501X mutation in the gene encoding filaggrin, one of the strongest genetic predictors of AD, confers an even greater risk for ADEH in both European and African ancestry populations, suggesting a role for defective skin barrier in this devastating condition.

Successful strategies for managing atopic dermatitis require an accurate diagnosis, identification and elimination of exacerbating factors including irritants and allergens, adequate hydration of the skin, control of pruritus and infections, and appropriate use of topical anti-inflammatory and other medications. Proper patient education increases the chances of successful therapy.

Atopic eczema (AE) is a chronic inflammatory skin disease characterized by pruritus, dry skin and an ongoing course of exacerbations and remissions. AE is a common disorder in children with a worldwide cumulative prevalence of 15-20% in this age group. AE has a strong familial predisposition. While AE is a complex disease with multiple gene involvement, recent interest has focused on genes involved in skin barrier/epidermal differentiation and in immune response/host defense. Recent developments and future directions on pathogenesis, diagnosis, natural course and prognosis are discussed.

Background: Individuals with atopic dermatitis (AD) have frequent colonization and infection with Staphylococcus aureus. Rapid elimination of S. aureus depends on constitutive synthesis and mobilization of human beta-defensin-3 (HBD-3)., Objective: To determine whether keratinocytes in AD, compared with normal, skin are less able to kill S. aureus rapidly, and to assess the potential role that abnormally low mobilization of HBD-3 onto S. aureus has in this process., Methods: Skin samples from 10 normal individuals and 10 patients with AD were compared for synthesis and mobilization of HBD-3 onto surface-associated S. aureus. Furthermore, keratinocytes from 10 individuals were studied for the effects of T(H)2 cytokines on the ability of the cells to synthesize and mobilize HBD-3, and to kill S. aureus., Results: Keratinocytes in skin biopsies from subjects with AD were defective in killing S. aureus relative to normal individuals (P < .001). The constitutive levels of HBD-3 in the epidermal keratinocytes were similar between normal individuals and those with AD. However, the cells of patients with AD were unable to mobilize HBD-3 efficiently to kill S. aureus. Physiologic Ca(++) was essential for development of normal HBD-3 levels by cultured human keratinocytes. Mobilization of HBD-3 and the ability to kill S. aureus were significantly (P < .05) inhibited by IL-4 and IL-13. Antagonism of IL-4/10/13 with antibodies significantly (P < .01) improved mobilization of HBD-3 onto the surface of S. aureus by skin from patients with AD., Conclusion: Patients with AD have problems with S. aureus skin infection. This is a result of increased levels of T(H)2 cytokines, which inhibit keratinocyte mobilization of HBD-3.

Objective: To examine the efficacy and safety of MAS063DP (Atopiclair) cream in the management of mild to moderate atopic dermatitis in infants and children., Study Design: One hundred forty-two patients aged 6 months to 12 years were administered MAS063DP (n = 72) or vehicle (n = 70) cream 3 times per day to affected areas and sites prone to develop atopic dermatitis. The primary endpoint for efficacy was the Investigator's Global Assessment at day 22. Secondary endpoints included Investigator's Global Assessment at other time-points, patient's/caregiver's assessment of pruritus, onset, duration of itch relief, Eczema Area and Severity Index, subject's/caregiver's assessment of global response, and need for rescue medication in the event of an atopic dermatitis flare., Results: MAS063DP cream was statistically more effective (P < .0001) than vehicle cream for the primary endpoint and all secondary endpoints. Treatment discontinuation as a result of an adverse event occurred in 9.9% of patients using MAS063DP cream and 16% of patients using vehicle cream., Conclusion: MAS063DP cream is effective and safe as monotherapy for the treatment of symptoms of mild to moderate atopic dermatitis in infants and children.

Atopic dermatitis is a common, complex disease that frequently follows a chronic, relapsing course. The disease can impact the quality of life (QOL) of patients and families to a significant degree. Patients and caregivers may focus on unproven triggers at the expense of proper skin care. A multidisciplinary approach is needed to comprehensively evaluate triggers and response to treatment, address confounding factors including sleep disruption, and educate patients and caregivers.

Atopic dermatitis (AD) increases health care utilization, affects patient quality of life, places a burden on caregivers, decreases patient/parent productivity, and adds to health care costs. Few studies have examined the effect of specific treatment modalities across a variety of AD-related outcomes. This prospective, multicenter, open-label longitudinal study of adult and pediatric patients with moderate to severe AD was conducted to evaluate the effect of a specific therapeutic intervention on AD-related outcomes over a period of 6 months. Surveys collected physician clinical assessments and patient- and caregiver-reported data across the following domains: clinical outcome, health care utilization/costs, quality of life, physical appearance, productivity/absenteeism, and medication compliance. This study is intended to help guide future research efforts on the net costs and benefits of different interventions across a diverse set of domains and in larger populations.

Extrinsic atopic dermatitis (EAD) and intrinsic atopic dermatitis (IAD) patients suffer from recurrent bacterial and viral infections. In this study, we demonstrate significantly decreased expression of human beta defensin (HBD)-3, a potent antimicrobial peptide (AMP), in lesional skin of both IAD (p<0.01) and EAD patients (p<0.01), as compared to psoriasis patients. Using primary keratinocytes from EAD and IAD patients, we determined that the deficiency in HBD-3 expression is an acquired rather than a constitutive defect. Furthermore, we demonstrate the down-regulatory effect of IL-4, IL-10, and IL-13 - which are over-expressed in the skin of AD patients - on HBD-3 expression in keratinocytes. Additionally, treatment of EAD skin explants with antibodies against IL-4, IL-10, and IL-13 augmented the expression of HBD-3. These studies suggest that neutralizing the Th2 cytokine milieu in AD skin may augment the innate immune response against bacterial and viral pathogens.

There are remarkable differences in the diagnostic and therapeutic management of atopic dermatitis practiced by dermatologists and pediatricians in different countries. Therefore, the European Academy of Allergy and Clinical Immunology and the American Academy of Allergy, Asthma and Immunology nominated expert teams who were given the task of finding a consensus to serve as a guideline for clinical practice in Europe as well as in North America. The consensus report is part of the PRACTALL initiative, which is endorsed by both academies.

Background: The cathelicidin family of antimicrobial peptides is an integral component of the innate immune response that exhibits activity against bacterial, fungal, and viral pathogens. Eczema herpeticum (ADEH) develops in a subset of patients with atopic dermatitis (AD) because of disseminated infection with herpes simplex virus (HSV)., Objective: This study investigated the potential role of cathelicidins in host susceptibility to HSV infection., Methods: Glycoprotein D was measured by means of real-time RT-PCR as a marker of HSV replication in skin biopsy specimens and human keratinocyte cultures. Cathelicidin expression was evaluated in skin biopsy specimens from patients with AD (n = 10) without a history of HSV skin infection and from patients with ADEH (n = 10)., Results: The cathelicidin peptide LL-37 (human cathelicidin) exhibited activity against HSV in an antiviral assay, with significant killing (P < .001) within the physiologic range. The importance of cathelicidins in antiviral skin host defense was confirmed by the observation of higher levels of HSV-2 replication in cathelicidin-deficient (Cnlp-/-) mouse skin (2.6 +/- 0.5 pg HSV/pg GAPDH, P < .05) compared with that seen in skin from their wild-type counterparts (0.9 +/- 0.3). Skin from patients with ADEH exhibited significantly (P < .05) lower levels of cathelicidin protein expression than skin from patients with AD. We also found a significant inverse correlation between cathelicidin expression and serum IgE levels (r2 = 0.46, P < .05) in patients with AD and patients with ADEH., Conclusion: This study demonstrates that the cathelicidin peptide LL-37 possesses antiviral activity against HSV and demonstrates the importance of variable skin expression of cathelicidins in controlling susceptibility to ADEH. Additionally, serum IgE levels might be a surrogate marker for innate immune function and serve as a biomarker for which patients with AD are susceptible to ADEH., Clinical Implications: A deficiency of LL-37 might render patients with AD susceptible to ADEH. Therefore increasing production of skin LL-37 might prevent herpes infection in patients with AD.

Background: MAS063DP cream has received marketing authorization in the US and the European Union for symptom relief of atopic dermatitis (eczema) and contact dermatitis., Design: A multicenter, randomized, vehicle-controlled, phase IV study was completed in the US., Methods: 218 patients aged 18 to 84 years joined this 50-day study. Patients self-administered MAS063DP cream (N=145) or vehicle cream (N=73) 3 times per day to affected areas and those areas prone to be affected. The primary endpoint for efficacy was the change in EASI at Day 22 of treatment, comparing the 2 treatment groups. Secondary outcomes included EASI scores at other time points, IGA, pruritus (100mm VAS), % BSA, and the need for rescue medication., Results: MAS063DP was statistically (p<.0001) more effective than vehicle in all outcomes at all time points. The incidence of rash was 2.1% in the MAS063DP group versus 5.5% in the vehicle group. Only 2 patients discontinued MAS063DP due to an adverse event., Conclusion: MAS063DP cream was confirmed to be a safe and effective treatment for mild to moderate atopic dermatitis in adults.

Background: IL-31 is a newly discovered T-cell cytokine that, when overexpressed in mice, results in pruritus and skin dermatitis resembling human atopic dermatitis (AD)., Objective: We sought to investigate the expression of IL-31 and IL-31 receptor A (IL-31RA) in skin biopsy specimens and peripheral blood cells from patients with AD and healthy individuals., Methods: Expression of IL-31 and IL-31RA was evaluated in skin biopsy specimens from patients with AD and healthy individuals by means of immunohistochemistry and RT-PCR. IL-31 protein production by skin-homing cutaneous lymphocyte antigen (CLA)-positive T cells was also assessed., Results: IL-31RA protein was expressed by keratinocytes and infiltrating macrophages in skin biopsy specimens from patients with AD. Comparisons between skin from patients with AD and healthy skin showed IL-31RA expression at higher levels on epidermal keratinocytes in AD samples. Infiltrating cells, more numerous in skin from patients with AD compared with that of healthy individuals, expressed IL31 mRNA. Histomorphometric analysis of these cells indicated they were of the lymphocytic lineage, with the majority of cells staining positive for CLA and CD3. IL31 mRNA and protein expression is largely restricted to CD45RO(+) (memory) CLA(+) T cells in peripheral blood of patients with AD and healthy volunteers. Moreover, circulating CLA(+) T cells from patients with AD, but not from patients with psoriasis, are capable of producing higher levels of IL-31 compared with CLA(+) T cells from healthy individuals. However, the average levels of IL-31 were not significantly different between patients with AD and healthy individuals., Conclusion: We provide evidence that IL-31 expression is associated with CLA(+) T cells and might contribute to the development of AD-induced skin inflammation and pruritus.

The prevalence of atopic dermatitis is increasing, and more than 50% of children with atopic dermatitis go on to develop asthma and allergies. A better understanding of the underlying immune abnormalities of this complex chronic relapsing skin disease is needed. Although the optimal treatment approach remains to be defined, several recent studies suggest a rationale for using topical calcineurin inhibitors as early intervention and adding topical corticosteroids as rescue therapy if needed.

Atopic dermatitis is a common, chronic, relapsing inflammatory skin disease frequently affecting infants and children. The worldwide prevalence of atopic dermatitis is estimated to be 5--20% of the paediatric population. First-line therapy has generally consisted of dry skin care, avoidance of triggers, application of topical corticosteroids, and administration of antihistamines and oral antibacterials. Topical corticosteroids improve the lesions of atopic dermatitis; however, concern on the part of physicians and patients regarding adverse effects has led to reluctance to utilise topical corticosteroids early and especially for prolonged periods. Topical immunomodulators (TIMs), including tacrolimus ointment and pimecrolimus cream, were recently introduced for the treatment of atopic dermatitis. Clinical data show that TIMs are effective in atopic dermatitis, yet do not cause the significant adverse effects associated with topical corticosteroids. Questions remain regarding the place of TIMs as a treatment for atopic dermatitis and how to use them most effectively, from both therapeutic and pharmacoeconomic standpoints. Specifically, two major issues remain unresolved: (i) how TIMs measure up to other therapies, especially topical corticosteroids; and (ii) how members of the TIM drug class compare against each other. Previous research has established that atopic dermatitis has a significant impact on quality of life (QOL) and carries a substantial economic burden. Some studies have also measured the utility of various atopic dermatitis disease states. While there is a need for further research, early economic studies provide evidence that TIMs positively affect the QOL of patients and families. In certain patients, TIMs may be cost effective and have an acceptable incremental cost utility compared with topical corticosteroids.Making cost-effectiveness comparisons between tacrolimus and pimecrolimus is challenging because there are limited head-to-head comparative data. Given currently available efficacy data, the results of one study suggest that tacrolimus may be more cost effective than pimecrolimus in paediatric patients with moderate atopic dermatitis. The full economic and QOL benefits of both agents are yet to be completely understood. The studies reviewed herein are the first to delineate the pharmacoeconomic benefits of TIMs in atopic dermatitis, and lay the foundation for future analyses. TIMs represent an exciting advance in the treatment of atopic dermatitis. Additional research will help determine the proper place of TIMs among the current array of therapeutic options for atopic dermatitis.

Chronic urticaria (CU) in children often is caused by physical triggers. It also can be associated with autoimmune disease, especially thyroid autoimmunity. Functional autoantibodies against FcepsilonRIalpha have been reported in children with CU but have not been studied in a systematic fashion. The autologous serum skin test has been proposed as a surrogate test to define the presence of these autoantibodies, although it identifies the presence of histamine-releasing factor, not necessarily antibody. Second-generation antihistamines usually are preferred for chronic therapy. Leukotriene receptor antagonists may be of benefit in a subset of children with CU.

Topical therapy of atopic dermatitis should incorporate an understanding of the underlying immune abnormalities of this complex chronic skin disease. Avoidance of irritants and proven allergens, skin hydration, and use of emollients and anti-inflammatory therapy help maintain a normal skin barrier. Topical calcineurin inhibitors have been added to the topical treatment armamentarium. Although the optimal treatment approach remains to be defined, several studies suggest the use of topical calcineurin inhibitors as early intervention therapy and topical corticosteroids as rescue therapy.

Objective: To evaluate pimecrolimus cream 1% and tacrolimus ointment 0.03% in pediatric patients with moderate atopic dermatitis (AD)., Methods: 141 patients (aged 2-17 years) were randomized to treatment with pimecrolimus cream 1% (n=71) or tacrolimus ointment 0.03% (n=70) twice daily for 6 weeks., Results: At day 4, local, application-site reactions were less common and of shorter duration with pimecrolimus than with tacrolimus. Incidence of erythema/irritation was 8% (6/71) with pimecrolimus compared with 19% (13/70) with tacrolimus (P=.039). Fewer patients receiving pimecrolimus (0%, 0/6) experienced erythema/irritation lasting >30 minutes, compared with those receiving tacrolimus (85%, 11/13; P <.001). Fewer patients reported itching with pimecrolimus (8%; 6/71) than with tacrolimus (20%; 14/70; P=.073). Incidence of warmth, stinging, and burning was similar in both groups; however, reactions lasting >30 minutes were fewer with pimecrolimus (0%, 0/14) than with tacrolimus (67%, 8/12; P <.001). More patients receiving pimecrolimus rated ease of application as 'excellent' or 'very good', compared with tacrolimus (76% vs 59%, respectively; P <.020). Efficacy was similar in both groups at day 43. Both treatments were generally well tolerated with no unexpected adverse events., Conclusion: Pimecrolimus cream 1% had better formulation attributes and local tolerability than tacrolimus ointment 0.03% while providing similar efficacy and overall safety in pediatric patients with moderate AD.

Atopic dermatitis is a chronic inflammatory skin disease associated with cutaneous hyperreactivity to environmental triggers and is often the first step in the atopic march that results in asthma and allergic rhinitis. The clinical phenotype that characterizes atopic dermatitis is the product of interactions between susceptibility genes, the environment, defective skin barrier function, and immunologic responses. This review summarizes recent progress in our understanding of the pathophysiology of atopic dermatitis and the implications for new management strategies.

Background: Atopic dermatitis (AD) and psoriasis are the two most common chronic inflammatory skin diseases. Both of these diseases have distinct clinical findings and specific inflammatory cell infiltrates. Previous reports have focused individually on one or two genes or gene products in the lesions of both skin diseases. However, they have not captured the complex gene expression that must occur to induce specific cellular infiltrates in the skin lesions of these two diseases. DNA microarray studies allow the simultaneous comparison of thousands of messenger RNAs that may identify the disease-specific pattern of tissue inflammatory responses., Objective: To compare the complex gene expression pattern of AD versus psoriasis skin lesions., Methods: RNA was extracted from skin biopsy specimens of 6 patients with AD and 7 patients with psoriasis and analyzed with the use of Hu-U95Av.GeneChip microarrays. To confirm GeneChip results, real-time PCR of selected genes were performed., Results: In AD skin, a total of 18 genes including the CC chemokines, CCL-13/MCP-4, CCL-18/PARC, and CCL-27/CTACK showed a statistically significant, >2-fold increase of gene expression compared with psoriasis. In psoriasis skin, a total of 62 genes including CCL-4/MIP-1beta, CCL-20/MIP-3alpha, CXCL-2/GRO-beta CXCL-8/IL-8, and CXCR2/IL-8R showed a >2-fold increase of gene expression compared with AD skin. Real-time PCR confirmed several of these GeneChip results., Conclusions: These results show a very distinctive gene expression pattern in AD as compared with psoriasis that may explain several features of AD and psoriasis including the specific inflammatory cell infiltrates observed in these disorders, that is, T(H)2 cells, eosinophils, and mast cells in AD and T(H)1 cells and neutrophils in psoriasis. Such observations may contribute to a characteristic "signature" for these two skin diseases.

Treatment of atopic dermatitis requires a comprehensive approach that includes evaluation of potential triggers and education of the patient and family regarding proper avoidance measures. Hydration of the skin and maintenance of an intact skin barrier remain integral to proper management. Although topical corticosteroids have been a mainstay of anti-inflammatory therapy, the newer topical calcineurin inhibitors offer advantages for treatment of this chronic, relapsing disease. Studies aimed at defining optimal combination therapy and early intervention might change the treatment paradigm for atopic dermatitis.

Background: Few cost-effectiveness analyses have been conducted on topical therapies for atopic dermatitis., Objective: We sought to compare cost-effectiveness of high-potency topical corticosteroids (HPTCs) and tacrolimus ointment for the treatment of moderate to severe atopic dermatitis for patients who are not responsive to or not well controlled with mid-potency topical corticosteroids., Methods: A Markov model represented the cyclic nature of atopic dermatitis. Clinical outcomes were derived from published literature. "Efficacy" was defined as disease-controlled days on which patients experienced a greater than 75% improvement in their disease. Resource use and changes in management were on the basis of opinions of a physician panel; secondary treatment was an oral antibiotic with topical corticosteroids. Sensitivity analyses were conducted for all variables., Results: The model was sensitive to duration of continuous treatment with HPTCs. HPTCs, when limited to 2-week treatment cycles, were associated with the highest total costs ($1682 per year) and the least efficacy (185 disease-controlled days). HPTCs in 4-week treatment intervals and tacrolimus ointment were similar in total costs and efficacy ($1317 vs $1323 for 194 vs 190 disease-controlled days, respectively). Although primary drug costs were higher for patients treated with tacrolimus ointment, patients treated with regimens of HPTCs incurred higher secondary drug costs., Conclusion: In the base case analyses, tacrolimus ointment was more cost-effective than HPTCs administered in 2-week treatment cycles, and similar in cost-effectiveness to 4-week cycles of HPTCs.

Background: In atopic dermatitis (AD) there is evidence of tissue fibrosis involving a number of structural changes, including papillary dermal fibrosis and epidermal hyperplasia. These changes are suggested to be the result of chronic inflammation of the skin. Several remodeling-associated cytokines, including transforming growth factor (TGF) beta1, IL-11, and IL-17, have been shown to be increased in allergic diseases, including asthma., Objective: We investigated TGF-beta1, IL-11, and IL-17 expression in skin biopsy specimens recovered from acute and chronic skin lesions from patients with AD, as well as from uninvolved skin of patients with AD and skin from healthy volunteers. We also examined the correlation between the expression of these cytokines and the extent of total, type I, and type III collagen deposition., Methods: We evaluated the expression of TGF-beta1, IL-11, and IL-17 by means of immunohistochemistry. Collagen deposition was assessed by means of immunohistochemistry and van Gieson staining., Results: TGF-beta1 expression was markedly enhanced in both acute and particularly chronic lesions (P <.001). Although IL-11 expression was significantly increased only in chronic lesions (P <.0001), IL-17 was preferentially associated with acute lesions (P <.005). Although collagen type III deposition was not significantly different among the groups, type I collagen deposition was significantly increased in chronic AD lesions (P <.0005). There was a significant correlation between IL-11 and type I collagen deposition, as well as the number of eosinophils in skin specimens from patients with AD (r (2) = 0.527, and r (2) = 0.622, respectively; P <.0001)., Conclusion: These results suggest that TGF-beta1, IL-11, and IL-17 are involved in the remodeling of skin lesions in patients with AD. However, IL-11 and IL-17 are preferentially expressed at different stages of the disease. Type I collagen appeared to be the major subtype involved in this repair process.

During the past year there have been significant advances in our understanding of the mechanisms underlying allergic skin diseases. This article reviews some of these advances in atopic dermatitis and urticaria. The introduction of a new class of topical anti-inflammatory medications, topical calcineurin inhibitors, has significantly increased our treatment options and led to a rethinking of potential management approaches in atopic dermatitis.

Atopic dermatitis is a common skin disease with a complex immunopathology that has a significant impact on the quality of life of patients and their families. Although topical corticosteroids have been the cornerstone of therapy, safety concerns, especially in children, with potent preparations or with chronic use have prompted treatment with various adjunctive therapies. Recently, topical calcineurin inhibitors, including tacrolimus and pimecrolimus, have been shown effective as monotherapy for this chronic relapsing disease.

Background: The ascomycin derivative pimecrolimus (ASM 981) is a cell-selective cytokine inhibitor, specifically developed for the treatment of inflammatory skin diseases., Objective: When applied topically, pimecrolimus cream 1% has shown promise as a treatment for inflammatory skin conditions, including atopic dermatitis (AD) in children and adults, allergic contact dermatitis, and chronic contact irritant hand dermatitis in adults., Methods: In two independent 6-week, randomized, multicenter studies of identical design, the efficacy and safety of pimecrolimus cream 1% in children with predominantly moderate AD were compared with vehicle. Pooled data from a total of 403 patients were used in the analysis. The primary efficacy parameter was the Investigator's Global Assessment (IGA) score. Secondary parameters included Eczema Area and Severity Index (EASI) and severity of pruritus scores. Subjects were also asked to assess their disease control as uncontrolled, limited, good, or complete., Results: Significant therapeutic benefits relative to vehicle were observed in the pimecrolimus-treated group at the first efficacy assessment, 8 days after initial application of the study medication (eg, relief of pruritus). At each subsequent postbaseline visit, pimecrolimus-treated patients showed significant improvement relative to controls in all efficacy measures. The medication was well tolerated., Conclusion: Pimecrolimus cream 1% appears to be a safe and effective alternative to currently used therapies for AD.

Background: Atopic dermatitis/eczema (AD/E) is a common disease. Few studies have attempted to quantify the cost to third-party payers., Objective: Our purpose was to identify the annual cost of medical services and prescription drugs for the treatment of AD/E to private insurance and Medicaid payers in the United States., Methods: We used a retrospective study design employing claims data from 1997 and 1998 from a private insurer and a state Medicaid program to analyze costs incurred. Beneficiaries were considered to have AD/E if they had at least one claim in 1997 with a primary or secondary listing of 1 of 3 diagnosis codes: 691.8, other atopic dermatitis and related conditions; 692.9, contact dermatitis and other eczema when no cause is specified; or 373.3, noninfectious dermatoses of eyelid. Patients who did not meet the diagnosis criteria served as a control group in each payer for comparisons of expenditures with the AD/E group., Results: Disease prevalence was 2.4% (private insurer) to 2.6% (Medicaid) of all eligible beneficiaries, and 3.5% to 4.1% of patients submitted at least one health care claim during the study period. Medicaid-insured patients used outpatient hospital visits and hospitalizations at a greater rate than did privately insured patients; neither used emergency departments extensively. The third-party payer cost of illness for AD/E ranged from $0.9 billion to $3.8 billion when projected across the total number of persons younger than 65 years insured by private insurers and Medicaid in the United States. More than one fourth of all health care costs for patients with AD/E may be attributed to AD/E and co-morbid conditions., Conclusions: Annual costs of AD/E are similar to those of other diseases such as emphysema, psoriasis, and epilepsy. Patients incur significant costs associated with AD/E and co-morbid conditions.