North Dallas Dermatology Associates 8144 Walnut Hill Lane Suite 1300. Dallas Texas 75231. Phone: (214) 420-7070. Fax: (214) 420-7380. Directions. Our Hours: Mon-Thurs: 8:00AM - 4:00PM. Friday: 8:00AM - 1:00PM. Free parking is available on the ground level of the parking garage directly attached to the BB&T bank..