About Us

At Center City Dermatology we do more then just treat your skin. In addition to providing you with a comprehensive and customized treatment plan, we strive to educate our patients about the health of their skin. Having a better understanding of how to take care of your skin and a personalized regimen to use at home, your skin will be set up for success!



Stephen D. Hess, M.D., Ph.D. is a board-certified Dermatologist with extensive experience in all aspects of medical, surgical, and cosmetic dermatology. Dr. Hess completed his dermatology residency at the University of Pennsylvania, one of the top-ranked dermatology training programs in the country. While at the University of Pennsylvania, Dr. Hess also completed a one year fellowship in cutaneous oncology which allowed him to develop additional expertise in the diagnosis and management of skin cancer. He received comprehensive training in pediatric dermatology at the Children’s Hospital of Philadelphia. Dr. Hess has been practicing in the Philadelphia / South Jersey region since 2008.

A native of Buffalo NY, Dr. Hess graduated from the State University of New York at Buffalo School of Medicine where he earned both his medical degree (M.D.) and a doctorate (Ph.D.) in Immunology at the Roswell Park Cancer Institute. He completed his undergraduate education at Wake Forest University in Winston-Salem, NC.

Dr. Hess has published extensively in top medical journals in the fields of dermatology and oncology, and has lectured at numerous local and national meetings. He is a member of the American Academy of Dermatology (AAD), the American Society for Dermatologic Surgery (ASDS), the American Society for Mohs Surgery (ASMS), the Pennsylvania Academy of Dermatology (PAD), and the Philadelphia Dermatologic Society. Dr. Hess is also a Clinical Associate of Dermatology at the University of Pennsylvania, where he is involved in teaching dermatology residents and medical students.

Dr. Hess is currently accepting new patients. He is committed to providing the highest quality medical care in a patient-friendly environment.


Dr. Tina Ho is a fellowship-trained facial plastic and reconstructive surgeon and board-certified head and neck surgeon. She attended the College of William and Mary as a 1693 Scholar. Dr. Ho then received her medical degree at the University of Virginia. She matched into the highly competitive specialty of Otolaryngology – Head and Neck Surgery and completed a five-year residency at the University of Kansas Medical Center. Dr. Ho then pursued a fellowship in facial plastic and reconstructive surgery at the University of Illinois in Chicago and trained under world-renowned leading authorities in rhinoplasty, aging face surgery, and injectable procedures.

Dr. Ho has childhood roots in the suburbs of Philadelphia and is proud to return and practice locally as Philadelphia’s female facial plastic surgeon. She is a member of the American Academy of Facial Plastic and Reconstructive Surgery and the American Academy of Otolaryngology – Head and Neck Surgery. As a female facial plastic surgeon, Dr. Ho upholds an approachable, relatable relationship with her patients and empowers them with beautiful, natural results. Dr. Ho is a face specialist and specializes in injectable treatments as well as surgery procedures.


Samantha Colosi, MS, PA-C, was born and raised in Southern New Jersey. In 2013, she completed her undergraduate studies in Malvern, PA, where she received a Bachelor of Science in Biology from Immaculata University. In July of 2015, she graduated from Philadelphia College of Osteopathic Medicine with a Master of Science in Physician Assistant Studies. Samantha specializes in medical and cosmetic dermatology, treating both children of all ages and adults. Samantha treats a variety of skin disorders including skin cancers, hair loss, acne, rosacea, warts, seborrheic dermatitis, psoriasis, and eczema. She also enjoys cosmetic dermatology where she can use her artistic talents to get patients the results they desire. Samantha is well known for her non-surgical techniques using Botox/Dysport and softi-tissue facial fillers such as Juvederm and Restylane. Lip fillers, in particular, have become one of her specialties and most sought after procedures.

Samantha is board certified by the National Commission on Certification of Physician Assistants and is registered in the states of Pennsylvania and New Jersey.

Brittany L. Flowers, MSN, CRNP, FNP-C

Brittany was born and raised in Bucks County, Pennsylvania and has been living locally in the City of Brotherly Love for the past several years. She joins us with seven years of experience in the Intensive Care Unit at the world-renowned Children’s Hospital of Philadelphia where she governed and chaired a patient safety committee and served as a preceptor and mentor to her nursing colleagues. Brittany graduated Magna Cum Laude with her Bachelor of Science in Nursing degree from the University of Pittsburgh and then went on to receive her Master of Science in Nursing degree from Thomas Jefferson University as a Family Nurse Practitioner. Brittany is registered as a Certified Nurse Practitioner through the American Academy of Nurse Practitioners.

Brittany has a special interest in dermatological care and strongly believes in providing individualized care to fit each patient’s unique needs and diagnosis. She specializes in treating a multitude of dermatologic conditions in both children and adults, including skin cancer, acne, psoriasis, rosacea, and atopic dermatitis. She focuses her visits on treating the patient, not just the diagnosis, and recognizes the importance of establishing trust and comfort when discussing a patient’s needs and building a treatment plan. Brittany’s goal is to provide a safe environment for her patients to openly and comfortably discuss their dermatological needs. Brittany enjoys treating patients and families throughout the lifespan and fine-tuning treatment to optimize a patient’s quality of life.

Brittany also specializes in surgical and cosmetic dermatology including surgical excisions of atypical moles/skin cancers/cysts, biopsies, and assessing/administering botulinum toxin injections (i.e., Botox® and Dysport®) She strives to provide high-quality cosmetic outcomes whether she is excising a skin cancer or removing a cosmetically distressing lesion.

Brittany is thrilled to be a member of our CCD team and looks forward to treating you!

Sarah Humbarger, MS, PA-C

Sarah Humbarger, MS, PA-C is an experienced board certified Physician Assistant in both medical and cosmetic dermatology. Sarah attended The University of Delaware where she received degrees in both Nutritional Science and Dietetics. She then completed her Masters in Physician Assistant Studies at Arcadia University in Glenside, PA in 2001. Since this time, she has been working in clinical dermatology in the Philadelphia region.
Sarah sees patients of all ages and treats all dermatologic conditions. She has a passion for treating psoriasis patients and has extensive experience and training with the biologic medications to treat this condition. She also treats acne, warts, skin cancers, rashes, eczema, and other medical dermatological conditions. Sarah has a passion for cosmetic treatments including but not limited to Botox, Dysport, and hyaluronic acid fillers. Sarah works with each patient to come up with a plan that will accomplish their skin care goals.
When not practicing medicine Sarah can be found spending time with her husband and four children. Sarah loves to run and exercise. She also enjoys her summers on Long Beach Island.
Sarah looks forward to working with you and providing you the most individualized skin care possible.


Amber is so excited to join the team at CCD where she started out as patient addressing her own skin concerns.
Amber’s dedication and curiosity of beauty and skincare started at a young age. Now has grown into a true passion. She took a leap of faith in 2020 and changed her career. Chasing her dream of helping others feel comfortable and confident in their own skin, by becoming an aesthetician. 
Amber studied at the prestigious Rizzeri Aveda School in Voorhees New Jersey, she holds a license in both NJ and PA.
Amber has been part of the Philadelphia restaurant industry for over a decade. The skills that she has developed in that time will be instrumental in her success as an aesthetician. Amber loves the authentic conversations that she has with patients and is attentive to help fulfill their personal goals. She is compassionate and dedicated to help others with theirs. 
Amber lives in South Philly with her cat Uma Purrman. She is completely in love with this city and all of the randomness it has to offer. When not in the office you’ll find Amber taking a spin class or seeking out live music.
Amber looks forward to the opportunity to be of service to all the patients at the Philadelphia location of CCD.


Kasey is a Philadelphia area native and a licensed medical aesthetician in our Exton office. After high school, she received her Bachelor of Arts in Communication Studies from Temple University.

Wanting a new adventure, she moved to Hilton Head Island where she worked in the hospitality industry for 7 years. During this time, she aimed to provide a memorable experience for each patron and mastered her customer service skills.

Kasey had struggled with acne for several years, which sparked her interest in skin care. Choosing to change career paths, she moved back to Philadelphia and graduated from the esthetics program at Chrome Institute of Cosmetology.

Kasey has experienced first-hand how skin issues can affect mental health and self esteem. Having this experience makes her the perfect travel buddy on your skin care journey, providing empathy and trust along the way. She understands not all skin is the same, and is eager to work with you to build a customized and sustainable skin care regimen. She enjoys learning the science behind different ingredients and each service offered. Kasey is also dedicated to continuing her education in order to provide the best results for her patients. She looks forward to seeing you in Exton!

Call 267.687.4437 to request an appointment in our Center City location. Or call 484.237.2432 for our Exton location!

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