Bronchial Reactivity test

[n.dave]

Hi there, I recently vistited my doctor to renew my class 1 medical. I mentioned that I experienced asthma last year during the summer time when doing some aerobic (running) exercise. My class 1 medical is on hold, pending to Bronchial Reactivity test. Does anybody knows which doctor to recommend/see? Currently, got hold of one but can't book a appointment.

Thanks
(UK, Liverpool)