What is the name of the condition of an allergic reaction causing itchy skin without rash that worsens with increased temperature? and treatment?

Urticaria?: Urticaria (aka Hives) is an itchy rash that worsens with heat and other factors like stress, alcohol, exercise, etc, however it almost always has a visible rash (red, raised whelps on skin) . Cholinergic urticaria specifically gets worse with heat and stress, but is smaller bumps on skin (again, a rash). not sure what you mean by itchy skin with no rash