An occupational therapist shall, after evaluating a patient and if the case is a medical one, refer the case to a physician for appropriate medical direction if such direction is lacking. Treatment by an occupational therapist of such a medical case may take place only upon the referral of a physician, osteopathic physician, podiatric physician and surgeon, naturopath, chiropractor, physician assistant, psychologist, optometrist, or advanced registered nurse practitioner licensed to practice in this state.