Inclusion Criteria:  Having moderate to severe atopic dermatitis:  Moderate atopic dermatitis is defined at screening and baseline as i) Atopic dermatitis body surface area (BSA) involvement ≥10%; and ii) Pruritus numerical rating scale (NRS) ≥3, Eczema Area and Severity Index (EASI) score ≥16 at screening and baseline, Investigator's Global Assessment (IGA)=3, or SCORing Atopic Dermatitis (SCORAD) is between 25 and 50. Severe atopic dermatitis is defined at screening and baseline as i) Atopic dermatitis BSA involvement ≥10%; ii) Eczema Area and Severity Index (EASI) score ≥20; iii) Investigator's Global Assessment (IGA) score = 4, or SCORAD ≥50. Initiating dupilumab therapy within 30 days of enrollment, according to the treating physician's decision independently of study participation. Participants and/or his legally approved representatives (LAR, in case of minor subject) agrees to sign an informed consent or an assent. Age of 12 years or above.  Exclusion Criteria:  Participation in another trial. Pregnancy or lactating or planning/intending to be pregnant in the next 6 months. Presence of active chronic or acute infection requiring systemic treatment Diagnosed active endoparasites infection, or suspected high risk of infection. Human immunodeficiency virus (HIV), hepatitis B or C, malignancy, or other concomitant illnesses.  The above information is not intended to contain all considerations relevant to a potential participation in a clinical trial.