About Us 

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Dr. Cathy Koger, D.O.

Dr. Cathy Koger is a board certified dermatologist and a fellow of the American Academy of Dermatology as well as a fellow of the American Osteopathic Board of Dermatology. Dr. Koger graduated with a BSE in Mechanical Engineering from the University of Michigan and worked as an engineer for over 6 years at Raytheon Systems Company and IBM. In 2003 she was Dr. Diane Kallgren’s running coach through the Bolder Boulder Training Club program. Dr. Kallgren’s love and enthusiasm for medicine and her patients convinced Dr. Koger to retire at an early age from engineering and pursue medical school. In 2006, prior to starting medical school, Dr. Koger was one of the first Medical Assistants at Kallgren Dermatology Clinic when Dr. Kallgren opened her practice. Dr. Koger attended medical school at A.T. Still University in Kirksville, Missouri from 2006-2010. She was accepted into Dermatology Residency at Northeast Regional Medical Center/Cleaver Dermatology from 2010-2014. She specializes in medical dermatology, surgical dermatology, cosmetics, and pediatric dermatology.

In her spare time, Dr. Koger enjoys the outdoors, training, and racing. She has been a runner, cyclist, and triathlete for over 30 years as well as a running/triathlon coach when not in medical school. She also loves spending time outdoors with her husband and daughters.

Curriculum Vitae


Brenda Winski NP-C

Brenda Winski is a board-certified nurse practitioner, nationally certified by the American Academy of Nurse Practitioners (AANP) and licensed by the state of Colorado. Prior to becoming a nurse practitioner, Brenda was an emergency room nurse for 15 years. She has also had the privilege of working in family practice/internal medicine before solely specializing in dermatology for the last 16 years.

Brenda is passionate about medical dermatology for children, adolescents and adults. She diagnoses and treats various dermatological conditions, with clinical interest in acne, benign skin lesions, eczema, psoriasis, rashes and skin cancer.

Brenda’s philosophy of patient care is to treat all patients like family. She takes pride in educating her patients to understand the full scope of their condition with the best possible treatment options available.

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Kirsten Revitte PA-C

Kirsten Revitte has been a Board Certified Physician Assistant since 2020 when she graduated from Midwestern University in Glendale, AZ with a Master’s in Physician Assistant Studies. She attended the University of Colorado at Boulder where she earned her Bachelor’s in Integrative Physiology and English Literature. After graduating from CU Boulder, she worked at K2 Dermatology as a medical assistant prior to attending her Physician Assistant program. Her time spent as a medical assistant confirmed her love of dermatology and she looked forward to cultivating long lasting relationships with her own patients. She is happy to treat a variety of dermatologic conditions with empathy and aims to promote skin cancer awareness and prevention.

After leaving Boulder for PA school, Kirsten is grateful to be back in her hometown with amazing access to the outdoors. She enjoys skiing, mountain biking and fly fishing with her husband, and when she is not outside, she relaxes with knitting or reading a good book.


Shannon Ross PA-C

Shannon Ross is a board-certified Physician Assistant specializing in dermatology. Shannon earned her undergraduate degree from the University of Colorado, Boulder, where she graduated Summa Cum Laude with distinction. Shannon then pursued a Masters's Degree and Physician Assistant Certification from Duke University in 2003. She has been a practicing, board-certified PA since then with extensive experience in both Dermatology and Family Practice.

Currently, she is proud to be a part of the dedicated team at K2 Dermatology, where she can prioritize the well-being of her patients. Shannon is dedicated to fostering a nurturing and welcoming environment for her patients, ensuring they feel seen, heard, and valued in their healthcare experience. Additionally, Shannon is fluent in Spanish.

Beyond her professional life, she finds joy in various outdoor activities. Skiing, jogging, gardening, and tennis are among her favorites. She also loves spending time with her husband and two teenage boys.


Samita Shah PA-C

Samita Shah has been passionate about healthcare since she began volunteering at a hospital in Michigan. She now has a bachelor's degree from Michigan State University in Human Biology, specializing in health promotion, where she remained on the Dean's List. Samita received her Master of Science in Physician Assistant Studies from Grand Valley State University in Grand Rapids, MI. She is fellowship trained in dermatology and is certified by the National Commission of Certified Physician Assistants. She is a member of the American Academy of Physician Assistants and Society of Dermatology Physician Assistants.

Although Samita is the newest member of our staff, she comes with many years of expertise specifically providing unmatched dermatological care to patients right here in Boulder, CO.

Samita was born and raised in Southwest Michigan, and she enjoys swimming, skiing, dancing, hiking, and improv.