This 10-item rating scale is designed for the assessment of psychophysiological insomnia and is composed of 10 different sections addressing latency, duration, continuity, depth of sleep, experience of sleepless nights, sleep-related thoughts or fear, and use of sleep medication. Total scores range from 0 to 40 points with higher scores indicative of more cognitive, behavioural, and emotional difficulties consistent with psychophysiological insomnia. Scores from 0-12 are considered normal and scores above the cutoff (13+) are indicative of symptoms consistant with psychophysiological insomnia that warrant further investigation.

Patients (on a voluntary basis) draw their itch-related perception, emotions, concerns, wishes and desires in a 10- minutes sketch. Drawings of CP patients usually contain additional diagnostic information not captured in usual history taking and might also be helpful to discuss treatment strategies in an "imaged-based" manner.

The Eight-item Patient Health Questionnaire (PHQ-8) is a tool for the screening of depression (presence and severity). PHQ-8 questions refer to the last two weeks, addressing the level of interest in doing things, feeling down or depressed, difficulty with sleeping, energy levels, eating habits, self-perception, ability to concentrate, speed of functioning and thoughts of suicide. The score range is 0 to 27 (0-4 = none- minimal, 5-9 = mild, 10-14 = moderate, 15-19 = moderate severe, 20-27 = severe)

The Somatic Symptom Scale-8 (SSS-8) is a brief version of the Patient Health Questionnaire-15 (PHQ-15) used to assess somatic symptom burden during the last two weeks. It measures the perceived burden of common somatic symptoms. (Score 0-3 = Severity: No to minimal. Score: 16 - 32 = Severity: Very high)

The Somatic Symptom Disorder - B Criteria Scale (SSD-12) is a brief self-report questionnaire used to assess the patient's perception of symptom-related thoughts, feelings, and behaviors during the last 30 days. The SSD-12 consists of 12 questions and measures three psychological sub-criteria (cognitive, affective, and behavioral) with scores between 0 and 4 (0 = never, 1 = rarely, 2 = sometimes, 3 = often, 4 = very often)

The WHO Disability Assessment Schedule 2.0 (WHODAS 2.0) consists of 12 questions, covers 6 domains of functioning (cognition, mobility, self-care, getting along, life activities, participation) and asks about difficulties during the last 30 days due to diseases or other health problems. The scores assigned to each of the items-"none" (1), "mild" (2), "moderate" (3), "severe" (4), and "extreme" (5)-are summed.

The Generalized Anxiety Disorder 7 (GAD-7) is a self- reported questionnaire for screening and assessment of the severity of generalized anxiety disorder (GAD). It consists of 7 questions including nervousness, inability to stop worrying, excessive worry, restlessness, difficulty in relaxing, easy irritation and fear of something awful happening. Each item is rated from 0-15+ ((0-4 = No to Low risk, 5-9 = mild, 10-14 = moderate, 15+ = severe)

SCORing Atopic Dermatitis (SCORAD) is a clinical tool for assessing the extent (A: according to the rule of nines; 20% of the score), the intensity composed of six items (B: erythema, oedema/papules, effect of scratching, oozing/crust formation, lichenification and dryness; 60% of the score; each item has four grades: 0, 1, 2, 3) and subjective symptoms (C: itch, sleeplessness; 20% of the score) which are rated on a 0-10 VAS.

The Eczema Area and Severity Index (EASI) is a tool used to measure the extent (area) and severity of atopic eczema. Inflamed areas of four body regions (head and neck, trunk, upper limbs and lower limbs) are assessed. The area score ranging from 0-6 is the percentage of skin affected by eczema for each body region (0 = no active eczema in this region, 1= 1-9%, 2 = 10-29%, 3 = 30-49%, 4 = 50-69%, 5 = 70-89%, 6 = 90-100%: the entire region is affected by eczema).

The Psoriasis Area and Severity Index (PASI) is a composite variable used to assess the severity of Psoriasis. The PASI evaluates the area of psoriatic involvement in 4 main areas (head, trunk, upper and lower extremities) and the severity of the psoriatic lesions with respect to three target symptoms: erythema, infiltration and desquamation, each to be rated on a scale from 0-4.

The Physician Global Assessment (PGA) relies on clinical assessment of the patient's skin presentation. The investigator (or qualified site personnel) scores the erythema, pustules, and scaling of all lesions on a scale from 0 to 4. Each component is graded separately, the average is calculated, and the final PGA is determined based on this composite score. A lower score indicates a lower severity, with 0 being clear and 1 being almost clear.

The Investigator's Global Assessment of Chronic Prurigo is designed to categorize the stage and activity of chronic prurigo and prurigo nodularis on scores from 0-4 each.

QST measures the detection threshold of accurately calibrated sensory stimuli (i.e. touch, vibration, thermosensation, pain). It quantifies individual sensory perceptions using direct patient feedback. Subject values are compared to normal data to determine whether the subject has a deficit in any modality.

The Vectra whole-body scanner is a high-definition 3D-visual documentation creating a 3D avatar, capturing nearly the entire skin surface. It monitors itch-related primary and secondary skin lesions, scratching patterns and treatment responses.