Number sign. Not to be confused with the Chinese character äº, the sharp sign (â¯), the viewdata square (â), the numero sign (â), the equal and parallel to symbol (â) or the game Tic-tac-toe's grid. The symbol # is most commonly known as the number sign, hash, or pound sign.
The poison ivy rash is not contagious. When a person touches the poison ivy leaf, a substance on the surface of the leaf (a resin) rubs off. Over the next 48 to 72 hours the skin reacts to the resin by becoming red and developing bumps and blisters at and around the site where the resin was.
Both are not contagious if the urushiol oil is not spread by chance. Infections can rarely result from itching. Both plants appear similar, produce the same kind of rash and require the same treatment. It depends on where you are residing in to differentiate a poison ivy rash from poison oak rash. The resin urushiol is the causative agent of contact dermatitis. The best way to prevent such rashes is avoiding exposure to them.