I would be most surprised linzian, though it doesn't hurt to ask. The DAME (aviation doctor) may ask you about the history of the scar to rule out anything serious. I was aked about a scar across the inside of my wrist, the result of a dog-bite. The DAME may have thought this could reveal a depressive mental disorder. That would be something that could preclude passing the medical as we wouldn't want a pilot flying his plane into the Houses of Parliament for instance. Expect then you may be asked about the scar to exclude anything sinister, but a straight-forward answer will have the doc moving on with the exam.
Good luck.