Could people with true wool allergy wear cashmere?

It depends: It depends of what type of allergic reaction you have to wool. If you have skin rashes on contact with wool, you might develop the same skin rashes to cashmere although skin rashes might be due to other factors too. If exposure to causing you to have nasal congestion, hives and shortness of breath, you might not want to wear cashmere also. Please see a local allergist for more details.