Amherst Office
Send Us a Message:
Front Royal Office
Cedar Creek Office

Join our community! Sign up in order to receive news, tips and to learn about special events automatically via email.

  • Facebook Social Icon

© 2019 by Dermatology Associates Inc. Proudly created with

Maria A. Bogaert, MD

Dr. Maria Bogaert is a board-certified dermatologist, dermatological surgeon, and a fellow of the American Academy of Dermatology. Born and raised in the Dominican Republic, Dr. Bogaert graduated summa cum laude from Universidad Nacional Pedro H. Urena. She completed dual residencies in Internal Medicine and Dermatology at the University of Miami School of Medicine, where she also served as chief resident. Dr. Bogaert has been in practice in Winchester, Virginia for over 20 years. She enjoys caring for both adults and children with disorders of the skin, and is interested in general and surgical dermatology.

Frederick G. Wenzel, MD

Dr. Wenzel graduated summa cum laude from Davidson College and completed his medical degree at Duke University with honors. In addition, he was a basic science research fellow at Harvard University as the recipient of the prestigious Sarnoff Fellowship Program, and was awarded a student research award from the National Institutes of Health. He completed an internship in Internal Medicine and a residency in Dermatology at Johns Hopkins Hospital, and was selected as chief resident in Dermatology during his final year. He has been practicing general and surgical dermatology in Winchester since 1997. His interests include medical dermatology, autoimmune dermatologic disorders, and skin cancer surgery.

Stephen H. Flax, MD

Dr. Stephen H. Flax is a board-certified dermatologist and a fellow of the American Academy of Dermatology. Dr. Flax attended medical school at the Albert Einstein College of medicine of Yeshiva University in Bronx, New York. He interned in Syracuse at the State University of New York Health Science Center, and completed his residency at the National Naval Medical Center in Bethesda, Maryland. Dr. Flax has practiced in Winchester, Virginia since 1999. In addition to his interest in general dermatology, Dr. Flax’s areas of expertise includes skin cancer, dermatological surgery, cosmetic fillers, laser tattoo removal, and Botox Injections.

Michael E. Mathieu, MD

Dr. Michael E. Mathieu is board-certified both by the American Board of Dermatology and by the American Board of Internal Medicine. He attended Medical School at Howard University in Washington D.C., and afterward completed dual residencies in Internal Medicine and Dermatology at the University of Virginia in Charlottesville. He also earned a fellowship in infectious disease from Harvard Medical School. Dr. Mathieu has practiced dermatology in Winchester, Virginia since 2001. His special interests include skin cancer, pediatric dermatology, and dermatologic manifestations of systemic disease.

Megan Armstrong, RN

Megan received her Bachelor of Science degree from James Madison University. She is a registered nurse with 15 years of experience in cosmetic dermatology. Prior to joining Dermatology Associates, Megan was employed at The Pennsylvania Hospital in Philadelphia Pennsylvania. Megan specializes in cosmetic fillers,  IPL laser treatment, facial veins, acne, rosacea, hyperpigmentation, and acne scarring. Megan welcomes the opportunity to meet with you to develop a customized treatment plan for your skin.

Humza Ilyas, MD

After graduating cum laude from Penn State University, Dr. Ilyas earned his medical degree from Jefferson Medical College in Philadelphia. He then completed his internship in internal medicine at the Western Pennsylvania Hospital in Pittsburgh and his dermatology residency at Albert Einstein College of Medicine in New York City. During his final year of residency, Dr. Ilyas was awarded the honor of chief resident in dermatology.  Dr. Ilyas then completed a fellowship in Mohs Surgery & Procedural Dermatology at the University of Wisconsin.


Dr. Ilyas specializes in Mohs surgery and advanced reconstructive techniques.  Dr. Ilyas is a diplomate of the American Board of Dermatology, a fellow of the American Academy of Dermatology, and a member of the American College of Mohs Surgery.  He has published widely and presented his findings at numerous medical conferences. In addition, he has written textbook chapters on nonmelanoma skin cancer for primary care physicians.

Jacqueline Wetherbee, NP

Jacqueline is a board-certified Family Nurse Practitioner specializing in dermatology. She graduated magna cum laude from James Madison University earning a Master of Science in Nursing. She is a member of the American Association of Nurse Practitioners and the Dermatology Nurses Association. Prior to becoming an NP, Jacqueline practiced as a Registered Nurse for 6 years and has worked in ICU, surgery, and interventional radiology at Duke University and the University of Virginia. 


Jacqueline has completed multiple rotations in dermatology in her NP program. She has volunteered personal time to shadow two dermatologists in the Shenandoah Valley as well as a Mohs surgeon in Richmond. She is passionate about skin cancer prevention as well as medical and surgical dermatology, and is excited about advancing her expertise with the dermatologists at Dermatology Associates.