Inclusion Criteria:  Participants, 6-17 years old at time of enrollment. Moderate to severe chronic AD inadequately controlled by topical treatment, diagnosed according to Hanifin and Rajka criteria by a pediatric dermatologist or allergist. AD severity will be determined at baseline with Validated Investigator Global Assessment (vIGA) score of moderate (3) or severe (4). Patient assessed or parent-proxy (under 8 years old) PROMIS sleep disturbance T-score ≥60. Willing and able to comply with visits and study-related procedures. On stable regimens (consistent use 14 days before Day 1 of study enrollment) of inhaled corticosteroids, topical steroids, and antihistamines.  Exclusion Criteria:  Poorly controlled asthma (Asthma Control Test ≤19). Self-reported sleep disturbance on 2 or more nights in the past 7 days due to allergic rhinitis. Use of concomitant medication that causes scratching. Major medical condition (such as cancer). Active condition that could affect sleep, such as obstructive sleep apnea, restless leg syndrome, insomnia, narcolepsy, severe sleep disordered breathing, severe depression, COVID-19, or hives (urticaria). Having applied topical steroids within 7 days of first or second PSG (important for biomarkers assessment). Use of systemic immunosuppressant within 30 days of first PSG. Having showered or used moisturizers within 12 hours of first or second PSG. Unable to communicate in English (some PROMIS questionnaires not available in translation). Other contraindication to receiving dupilumab (such as history of allergic reaction to dupilumab or any of its components). Pregnancy. Clinical blindness (circadian disturbing).