This study is for adults with cold induced urticaria or symptomatic dermographism. Urticaria refers to itchy hives that come from cold exposure, and dermographism means hives from skin scratching. The study checks if a drug called barzolvolimab works better than a placebo (a pill that does nothing) for these conditions, even if you've already tried H1-antihistamines (medicines for allergies).

The study lasts about 44 weeks. It starts with a 4-week screening period, then a 24-week treatment phase, and finally a 16-week follow-up. Barzolvolimab doses begin at 450mg and then 150mg later.

• You'll need to visit the study site and keep a daily symptom diary.
• Both men and women must use effective birth control during and after the study.
• Some people may not join if they have other health issues or are pregnant.

Ask your doctor if you qualify and to discuss any risks or benefits. They will help you decide if participating is right for you.