This study is about testing a cream called **Ruxolitinib** for people with **Prurigo Nodularis (PN)**, a skin condition that causes itchy bumps. The study will check if the cream is safe and works well. It will last about **12 weeks** where neither the participants nor the doctors know who gets the real cream or a placebo (a fake cream that looks real). After that, everyone gets the real cream for **40 weeks**, and there's a **30-day follow-up** to check safety.

To join, you need to have had PN for at least **3 months** and have at least **6 itchy spots** on your body. You shouldn't have other conditions that cause itching, be pregnant, or have certain skin or health problems.

• The study lasts about **12 months** in total with several visits.
• You cannot use certain medications or therapies during the study.
• There might be side effects, and you need to agree to avoid pregnancy.