Skin Pathology Assessment With Optical Technologies (SPOT): a Cross- Sectional Clinical Study in Atopic Dermatitis Patients and Healthy Subjects

A total of 80 participants will be recruited for the study spread equally across 4 cohorts, those with healthy skin, and those with a mild/moderate/severe eczema/dermatitis [AD] lesion on their inner elbow.

Our first point of contact with the participant involves providing them with a copy of the age-appropriate PIS and completing an expression of interest (EOI) form through phone/email/post. The EOI form contains questions for pre- screening purposes so that the likelihood of suitability can be estimated in order to avoid wasting the time of people who clearly don't meet the basic entry criteria (severity will need to be assessed during the screening visit). For volunteers who meet the basic entry criteria as outlined on the EOI form, the investigators will make it clear that the next step will be for a researcher on our team to contact them to arrange a screening/informed consent session at our test facility.

A member of the team will then contact interested volunteers to arrange their visit, at least 24 hours following the provision of the PIS. The bulk of the study consists of a single visit, which contains the full screening process, informed consent and the study protocol (A second short follow up visit 2-3 weeks later is also required for those providing biopsies).

When the participant arrives at either the Sheffield Children's Hospital (For adolescents) or the Royal Hallamshire Hospital Clinical Research Facility (Adults), a nurse will talk the participant through the study and what it involves. They will also be asked some basic questions about their skin and current medication. Their skin will be inspected visually by eye to assess eligibility and cohort allocation. If the participant is eligible, then they will be required to fill in an informed consent form (11-15 year olds will complete an assent form, with their legal guardian completing a consent form).

Following consent, the participants will be taken to the Royal Hallamshire Hospital Skin Research room. They will be asked to roll up their sleeves such that their elbows are able to acclimatise for 20 minutes. While waiting, the scan sites will be marked on the participants elbows using a washable ink (Scan sites on the cheeks will not be marked with ink) and a skin questionnaire will be conducted which asks basic questions about the history of eczema at each scan site. When ready, images will be collected from the scan sites using handheld probes which gently contact the skin surface. All of the images collected are completely harmless, and simply involve shining light into the skin. The following measurements will be collected in order: Clinical Photographs (From elbows and cheeks), Trans-epidermal water loss measurements (From elbows and cheeks), skin redness (From elbows and cheeks), FTIR spectra (From elbows and cheeks), Optical Coherence Tomography (From elbows and cheeks), Laser doppler images (From elbows), Polarisation-sensitive Optical Coherence Tomography (From elbows) and skin pH (From elbows and cheeks).