Efficacy of Tildrakizumab in Difficult-to-treat Areas in Psoriasis

Inclusion Criteria:

1. Patient with a diagnosis of moderate to severe chronic plaque psoriasis documentedin the medical record,

2. Disease diagnosis > 6 months (regardless of severity at diagnosis)

3. Involvement of at least one of the following areas: nails, scalp, genital,palmoplantar (non-pustular)

4. Indication for treatment by IL-23 inhibitor. Tildrakizumab must be the selectedIL-23 inhibitor therapy prior to enrolling the patient in the study. Patients whohave previously received previous treatment by IL-23 inhibitors may be included.

5. Patient 18 years of age or older at the inclusion visit

6. French social security beneficiary

Exclusion Criteria:

1. Patient unable to comply with study requirements (i.e.complete study questionnaires)

2. Patient who, in the opinion of the investigator, should not participate in thestudy. This opinion should be documented in the patient's record.

3. Patient included in an interventional clinical trial at inclusion.

4. Vulnerable patient or patient under court protection

5. Patients with known hypersensitivity to IL-23 inhibitors

6. Patients with HIV or active HBV or HCV infection at the time of inclusion

7. Patient with a history of untreated latent tuberculosis or active tuberculosis atinclusion

8. Patient with any other serious active infection present at inclusion thatcontraindicates IL23 inhibitors use.

9. Pregnant or lactating woman