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About Us


is73-1360094000-24970-150x150Murray A. Cotter, MD, PhD
Dr. Cotter grew up in the Detroit area, spending summers here in idyllic Emmet county of northern lower Michigan. After thirteen years of training at the University of Michigan in Ann Arbor where he received his BS, MD, and PhD degrees, Dr. Cotter took his residency training in Dermatology at the University of Utah in Salt Lake City. He subsequently completed a fellowship in Mohs surgery and cosmetic dermatology at the University of California at San Francisco (UCSF). Dr. Cotter is board-certified in dermatology by the American Board of Dermatology, and is a fellow of the American Academy of Dermatology, the American Society for Dermatologic Surgery, and the American College of Mohs Surgery. Dr. Cotter is the author of numerous scientific publications, textbook chapters, and holds a US patent.Dr. Cotter adheres to what he believes is the Golden rule of medicine: treat everyone as if they were your own mother, father, brother or sister. In his spare time, Dr. Cotter is an avid road and mountain cyclist and enjoys skiing, snowboarding, hiking, yoga, traveling and reading.

is37-1378401059-03510-150x150Sherri S. Vazales, MD
Dr. Vazales has been practicing dermatology for thirty years, fourteen of them here in Petoskey. She was born in Michigan but grew up mostly outside of the Chicago area, coming to Petoskey each summer as her family has for almost 100 years. She got her undergraduate degree at Stanford University in California and then her MD degree at University of California San Diego. She and her husband, Brad, a cardiothoracic surgeon, chose to move back to the Midwest to do their residencies at Washington University-Barnes Hospital. She initially joined the facility at Washington University after training, but eventually moved to Pennsylvania in private practice for 13 years. In 1999 she moved to Petoskey with her husband and family and started a practice here. She has seven children and four grandchildren that she loves spending time with when she’s not working. She has been Board Certified in Dermatology since 1983 and is a Fellow of the American Academy of Dermatology.

is67-1360094075-52300-150x150Tina M. Crook, PA-C
Tina attended Cental Michigan University PA program, and began her career in Family Medicine. She practiced Dermatology in Jackson, Michigan for four years prior to joining Dermatology Associates in January 2009 where she has a special interest in pediatric dermatology. Tina is married to Bill who is also a PA-C. Bill, originally from Charlevoix and Tina are happy to have been able to move back to Northern Michigan. She is the mother of three to daughter Adel, a son Owen, and baby Caroline. Tina enjoys spending time with her family, kayaking and gardening.

is58-1378400928-47915-150x150Karen S. Nigg, PA-C
Karen is an experienced dermatology physician assistant, a graduate from Saint Louis University. She grew up in Michigan and spent much time enjoying northern Michigan. She has a unique background of literally living all over the work as she is a retired Lt.Col from the USAF. She practices both general and cosmetic dermatology. She practiced in the St. Louis area then moved to Petoskey and has worked with Dr. Vazales since 2006. She enjoys getting to know her patients. She enjoys traveling, boating, biking, skiing, reading and enjoying her three daughters and two granddaughters.

GermainTracy D. St. Germain
Tracy D. St. Germain, MSN, RN, NP-C is a leading expert in Neuromodulators and Dermal Fillers. She is an Aesthetic Nurse Practitioner that has been injecting for more than 10 years. Tracy received a Master’s Degree in Nursing as a Family Nurse Practitioner from Marshall University, located in Huntington, West Virginia. Tracy has had the privilege of working and studying with the top injectors in the United States. She has had extensive training in facial anatomy and assessment. She specializes in facial voluminization and Advanced Technique procedures. Most recently Tracy held a position that allowed her to educate fellow injectors on the safest and most effective anti-aging injection techniques. Tracy currently practices at Franklin Dermatology and Surgical Center/Advanced Dermatology and Cosmetic Surgery, located in Southfield, Michigan.

StollMary Stoll
Mary Stoll has been working as a physician assistant in dermatology since 2008. Mary grew up in Michigan’s Upper Peninsula. She graduated with honors from Central Michigan University with a Bachelor of Science in Biology in 2004. She attended Western Michigan University’s College of Health and Human Services to pursue her goal of becoming a physician assistant, and graduated with a Master of Science in Medicine in 2008. At that time, Mary was awarded Western Michigan University’s Academic Award designating the highest academic achievement in her graduating class. Mary is certified by the National Commission on Certification of Physician Assistants.

Mary maintains professional memberships with the American Academy of Physician Assistants, the Society of Dermatology Physician Assistants, and the Michigan
Academy of Physician Assistants.

Mary joined Dermatology Associates of Northern Michigan in September 2015. She looks forward to continuing her career in dermatology, and truly enjoys caring for her patients with an emphasis on patient education and compassion.