Staphylococcal Toxins in Atopic Dermatitis and Eczema Herpeticum

Study Overview
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Brief Summary
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Atopic dermatitis (AD) is the most common chronic inflammatory skin disease. Clinical studies have demonstrated a link between staphylococcal skin colonization and the pathogenesis of AD, but the implication of bacterial virulence factors remains largely uncharacterized. Finally, AD is often associated with herpes simplex skin infections. The aim of this project is to investigate the role of staphylococcal toxins in the exacerbation and maintenance of atopic skin inflammation and in the occurrence of infectious complications such as eczema herpeticum.

Official Title
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Role of Staphylococci on Cytokine and T Cell Profiles in the Pathogenesis of Atopic Dermatitis and Eczema Herpeticum

Conditions
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Atopic Dermatitis, Staphylococcus Aureus, Bacterial Toxins, Immune Response, Cytokines, T Cells Subsets

Intervention / Treatment
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* Other: Skin biopsies and blood samples


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with moderate AD (SCORAD between 25 and 50) or severe AD (SCORAD> 50) Skin lesions in the forearms Free subject, without neither guardianship, wardship nor subordination Patient with Social Security Informed and signed consent by the patient after clear and loyal information on the study Exclusion Criteria: Age < 18 year-old Patients with mild AD (SCORAD < 25) Patients without skin lesions in the forearms Patients treated with dermocorticoid or calcineurin inhibitor for less than two weeks Patients under systemic treatment : Methotrexate, Ciclosporin, Mycophenolate Mofetil, Azathioprine, general corticosteroids for less than 4 weeks Patients under biological treatment : Dupilumab for less than 5 half-lives Patient without Social Security Pregnant and nursing women

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Skin biopsies and blood samples<br> | Other: Skin biopsies and blood samples<br>* Two skin biopsies and 30 ml of blood will be collected.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quantification of S. aureus colonization level and characterization of bacterial virulence profile in AD lesions. | Biological data obtained from lesional skin will be compared with those of healthy skin. | 2 hours (with consultation and sample) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Determination of the inflammatory profile of skin and blood during AD. Definition of the seric cytokine signature characteristic of AD. Characterization of the phenotype and function of the lymphocytic infiltrate T during AD. | Biological data obtained from lesional skin will be compared with those of healthy skin. | 2 hours (with consultation and sample) |