This is a prospective, single-center, class 2 study to better characterize the immune response in immune response in the blood of atopic dermatitis. Investigators are following in the referral center of Nice, 100 patients with atopic dermatitis. Investigators plan to include 30 patients. Blood samples will be collected to assess cytokine levels after non-specific immune stimulation. immune stimulation. Whole blood will be collected and stimulated with immune ligands (anti-CD3 T-cell stimulating ligands associated with Thymic Stromal LymphoPoietin (TSLP) or TLR agonist R848 7/8 agonist stimulating NK (natural killer) lymphocytes and promoting T cell response) on lyophilized freeze-dried spheres (LyoSphere, Qiagen) within 8 hours of blood collection.

Inclusion Criteria:

• Patient aged ≥ 18 years.
• Patient with clinically diagnosed atopic dermatitis according to the criteria of Hanifin and Rajka.
• Moderate to severe defined by an Investigator's Global Assessment ³3 and eligible to systemic treatment.
• If the subject is a woman of childbearing potential, she has a negative urine pregnancy test.
• Subject is non-pregnant, non-lactating and is not planning for pregnancy during the study period.
• Subject is in good general health and free of any known disease state or physical condition which, in the investigator's opinion, might impair his/her evaluation or which exposes the subject to an unacceptable risk by study participation.
• Subject is able to comprehend and willing to sign an Informed Consent and/or Assent Form.
• Affiliation to a social security scheme.
• Signed informed consent

Exclusion Criteria:

• Vulnerable person: pregnant or nursing woman, minor, adult under guardianship or deprived of liberty
• Patient with an infection
• Patient with other systemic inflammatory disease
• Patient with anti-inflammatory or immunosuppressive therapy
• Patient with a contraindication to JAK inhibitors
• Participants in other clinical therapeutic studies involving a drug that may interfere with the present evaluation