Long Term Observational Study to Collect in a Real-world populatIon Data on the Treatment Pattern of Secukinumab in Adult Patients With Moderate to Severe HS Within the Italian Population

Inclusion Criteria: Study participants eligible for inclusion in this study must meet all the following criteria: 1\. Male and Female patients who provide written informed consent and privacy form (ICF\&PF) to participate in the study. 2\. Aged ≥ 18 years at ICF\&PF signature. 3. Patients with moderate or severe HS (IHS4 and/or Hurley staging system, as assessed by the investigators) at index date. 4\. The start of secukinumab is within 30 days after the ICF\&PF signature (enrolment), as per local standard clinical practice. Patients were not treated with secukinumab before enrolment within the Managed Access Program (MAP). The initiation of secukinumab is based on dermatologist's own practice, regardless of study participation. For HRU and economic burden only: 5\. Patients who provide written ICF\&PF to allow the use of secondary (administrative) data for the purposes of this study. 6\. Patients with more than 12 months of residence inside the area of competence of the LHU (applicable only to study sites associated with the 6 LHUs). Exclusion Criteria: Study participants meeting any of the following criteria are not eligible for inclusion in this study: 7\. Participation in an ongoing clinical trial. 8. Any medical or psychological condition that may prevent study participation, based on practitioners' decision-making. For HRU and economic burden only: 9\. Patients will be excluded if the unique identifier does not allow them to be identified in the LHU administrative databases related to the site where they were enrolled.