Is it possible to have a panic attack with no physical symptoms?

Not exactly . . . : The intense fear or discomfort of a panic attack are associated with a combination of symptoms--most of which are physical. But, if a person is afraid of losing control, dying, or going crazy, and feels somehow detached from oneself or that reality has shifted, this begins to look like a panic attack. Your doctor can do a careful exam and help clarify what's happening.

Panic attack: During the attack, your autonomic nervous system is hyper functioning, so physical symptoms occur. In between attacks, you might experience apprehension & fear & worry, with little physical symptoms until another attacks starts.