*Exploring cytokine detection in the stratum corneum of psoriasis patients by two noninvasive methods: sampling by TAPE and Transdermal Analysis Patches (TAP).*

Although the majority of psoriasis patients can be sufficiently treated with
topical agents, some patients need more intensive or aggressive treatment such
as systemic treatment or biologics. Initiating such treatment early-on in this
group of patients might positively influence their course of disease and
quality of life. Identifying or predicting the course of disease of an
individual would enable us to give the appropriate treatment timely. Therefore,
we are searching for biomarkers that could predict the natural course of
psoriasis or (systemic) treatment response per individual patient. To minimize
the burden on patients and maximize the implementation potential, we are
searching for non-invasive methods to detect such biomarkers. Two non-invasive
methods, Transdermal Analyses Patches (TAP) and sampling of the stratum corneum
by adhesive tapes (TAPE), are able to measure cytokines or other soluble
factors deposited in the stratum corneum of the skin that might serve as
biomarkers. Although both methods are non-invasive, patients* perception of
these two methods and their applicability in daily clinical practice might
differ. We therefore seek to evaluate possible differences in patient
friendliness of both methods. In addition, we aim to assess the correlation
between the protein detection of both methods.

(I) To compare patient friendliness in adult psoriasis patients between two
non-invasive cytokine detection methods: TAP and TAPE. (II) To assess the
correlation in cytokine detection by TAP and TAPE stratum corneum sampling in
psoriasis patients.

An explorative, observational, non-invasive pilot study of protein detection in
the stratum corneum by two methods (TAP and TAPE) in adult psoriasis patients
at one timepoint during a regular outpatient clinic visit.

There are no immediate benefits for subjects participating in the study, but
this study enhances the knowledge on non-invasive methods to detect biomarkers
in the skin. This study will be incorporated in daily clinical practice.
Patients participating in this study will have their regular outpatient visits
and no extra visits so that the burden for the participating patient is
minimalized. During the regular visit, first one TAP will be applied for 20
minutes and thereafter a TAPE procedure will be performed. Some transient mild
erythema can be observed directly after collecting the TAPES, but as the
barrier function of the skin stays intact with this procedure, it will not
result in local skin irritation, scarring or post inflammatory
hyperpigmentation. Given the non-invasive nature of both the TAP and TAPE
procedures we estimate the study risks as *negligible*. Furthermore, given the
short application time (20 minutes) with application during regular visits at
one timepoint, we consider participation in this study acceptable.