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Dr. Diane Kallgren, M.D.

Dr. Diane Kallgren is board certified in Dermatology and a fellow of the American Academy of Dermatology. She graduated Phi Beta Kappa and summa cum laude from The Catholic University of America in Washington, DC, earning her Bachelor’s degree in biology. Dr. Kallgren earned her M.D. from the University of Missouri in Columbia, Missouri. Following medical school, she was an intern at Naval Hospital San Diego and then served as a General Medical Officer for four years in the U.S. Navy. Dr. Kallgren served on board the USS Jason in Hawaii and California and then was stationed at Naval Hospital, Rota, Spain. Dr. Kallgren completed her dermatology residency at the National Naval Medical Center in Bethesda, MD and then served 2 years at Portsmouth Naval Hospital, VA before departing naval service as a Commander and moving to Boulder, CO in 1994. She was a partner at another dermatology clinic in the Boulder area until February 2006 when she founded Kallgren Dermatology Clinic.

An avid runner, Dr. Kallgren also likes to bike, fly fish, hike and garden in her free time. She is married to Kevin Maguire, whom she met while they were both stationed in Spain while in the Navy. They have traveled extensively throughout Africa, South America, and Europe and have many adventures still on their bucket list.

Curriculum Vitae


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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 when Dr. Kallgren first 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 15 years as well as a running/triathlon coach when not in medical school. She also loves spending time with her husband and daughters.

Curriculum Vitae




Brooke (Myers) Cerkovnik, PA-C

Brooke (Myers) Cerkovnik has been a Board Certified Physician-Assistant (PA-C) since 2018 when she graduated with a Bachelor’s in Biology followed by a Master’s Degree in Physician Assistant Studies from Rocky Mountain College in Billings, MT. Upon graduation, she immediately began working in Dermatology where she cultivated her passion for all things skin. She loves establishing connections with patients and treating all types of dermatologic conditions. Brooke also enjoys community outreach and promoting skin cancer awareness and prevention.

Brooke recently moved to Colorado with her husband and joined Kallgren Dermatology in March 2020. In her spare time, she loves to play volleyball, is a novice foodie, and enjoys doing anything in the outdoors.




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 15 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.




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 Kallgren 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.