Psoriasis is a chronic inflammatory disease that affects between 2% and 4% of the French population.Some specific localizations are more difficult to manage, such as the scalp, nails, genital region and palmoplantar localizations.

Tildrakizumab, an anti-interleukin-23 (IL-23) monoclonal antibody, has demonstrated efficacy and safety in the treatment of patients with moderate to severe psoriasis.

Real-life data on the efficacy of Tildrakizumab in unselected patients with these difficult-to-treat locations are still limited.

The aim of the ZODIPSO study is to evaluate the efficacy and safety of Tildrakizumab in patients presented difficult to treat locations in psoriasis : nail, scalp, genital and palmoplantar.

The main objective is to assess the overall response and the specific response to Tildrakizumab at these specific areas up to W52.

Psoriasis is a chronic inflammatory disease that affects between 2% and 4% of the French population. Some specific localizations are more difficult to manage, such as the scalp, nails, genital region and palmoplantar localizations. They are reported at least once during the course of psoriatic disease in more than 80%, 50%, 60%, 12% of patients, respectively.

Despite recent progress in the management of the disease, these localizations remain a challenge for psoriasis patients because of their impact on quality of life and the difficulty of treating them.

Tildrakizumab, an anti-interleukin-23 (IL-23) monoclonal antibody, has already demonstrated efficacy and safety in the treatment of patients with moderate to severe psoriasis in two international multicenter randomized clinical trials : reSURFACE 1 and reSURFACE 2. However, real-life data on the efficacy of Tildrakizumab in unselected patients with these difficult-to-treat locations are still limited.

Inclusion Criteria:

1. Patient with a diagnosis of moderate to severe chronic plaque psoriasis documented in 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 selected IL-23 inhibitor therapy prior to enrolling the patient in the study. Patients who have 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 the study. 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 at inclusion
8. Patient with any other serious active infection present at inclusion that contraindicates IL23 inhibitors use.
9. Pregnant or lactating woman

Patients with a diagnosis of moderate to severe chronic plaque psoriasis with specific difficult-to-treat locations.