Clinical Relevance of Scratching and Sleep in Atopic Dermatitis

For Atopic Dermatitis patients the eligibility criteria are: Inclusion Criteria: * Patient has signed informed consent for the BioDay registry and is enrolled in the BioDay registry. * Patient has a diagnosis of moderate to severe Atopic Dermatitis, and therefore will be treated with advanced systemic treatment in daily practice according to the Dutch AD guideline (after treatment failure of at least 1 oral immunosuppressive drug or a contra-indication for oral immunosuppressive drugs). * Patient has no concomitant immunosuppressive therapy at baseline * Age between 18 and 65 years old (18 years ≤ Age ≤ 65 years). * Intact skin at both wrists (definition of intact skin: Skin in which there are no breaks, scrapes, cuts, or abnormal openings that allow pathogens to enter). * Willing and able to provide written informed consent and participate in study procedures. * Able to understand, read and write Dutch. Exclusion Criteria: * Unable to understand instructions * Expected participation of less than 5 weeks * Travelling or holiday, for 1 night or more, outside the Netherlands during participation in the study. * Eczema lesions on one or both wrists at study recruitment * Patients with neurological disease (e.g., Parkinson's Disease) or physical disability affecting one or both hands, wrist and/or arms. * Irregular or affected sleep/wake pattern due to causes other than AD. (For example: medical conditions like sleep-apnea or primary insomnia, concomitant medication affecting sleep, alternating shift workers or AD-patients with young infants.) * Having a tattoo on the upper side of one or both wrists. (Tattoos in the wrist area can cause inaccurate measurements.) * Institutionalized patients (e.g., care home residents) * Prisoners (general inmates of prisons or other state institutions) * Philips research employees * Study site employees or any other research team member involved directly or indirectly in the conduct of the clinical study * Cognitively impaired (diagnosis of cognitive impairment in medical file) * Pregnant persons will not be considered for this study (during pregnancy, the treatment with advanced systemic treatment is not always possible) * If a patient is not allowed to visit the hospital due to the prevailing COVID-19 restrictions. (If COVID-19 restrictions indicate that it is not allowed to visit the hospital for example when having a positive COVID-19 test, then the patient cannot be included in the study, because it cannot comply with the BioDay study protocol, and thereby indirectly also not with the AD-study protocol). For dermatology HCPs the eligibility criteria are: Inclusion criteria * HCP is allowed to treat AD-patients * HCP is (trainee) dermatologist, (trainee) physician, (trainee) research-physician, (trainee) nurse practitioner, (trainee) physician assistant or similar, working in the field of dermatology * HCP has (digitally) signed consent form for the focus group * HCP works in a hospital that is a member of the BioDay consortium. Exclusion criteria * Unable or unwilling to attend focus group * Philips Research employees