Compassionate healthcare is how we describe our 39 year old culture.  

Hennessey Dermatology LLC is a boutique dermatologic practice that has been operating for almost 4 decades with offices in Manhattan and in the Hamptons.  Headed by one of the leading dermatologists in the country, Dr. N. Patrick Hennessey created a culture based on lifelong doctor-patient relationship, compassion, and delivering highest quality dermatologic care available. 

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Dr. N. Patrick Hennessey MD

Head of Dermatology

 Dr. N. Patrick Hennessey is a highly accomplished, friendly dermatologist located in New York City (Manhattan) and in the Hamptons (Wainscott).  Dr. Hennessey earned his medical degree from Michigan State University and completed his internship in Michigan and continued an Internal Medicine residency at Harvard University's the Deaconess/Brigham Hospital.  He also completed both his residency in dermatology and his fellowship in Malignant Melanoma at the New York University Medical Center.

Dr. Hennessey is certified by the American Board of Dermatology.  His medical career is colored by many outstanding contributions to medicine, including several publications, research and scientific presentations.  Dr. Hennessey is on the medical staff of NYU Langone Medical Center and the Southhampton Hospital.  Dr. Hennessey is part of the NYU Medical School and the NY College of Osteopathic Medicine as well as serving as a Principal Investigator at the Manhattan Medical Research Group.

Dr. Hennessey is devoted to ensuring the longevity of his patients' health and developing long-lasting relationships with them.  He takes his time to understand symptoms and give correct diagnoses to ensure the continued health of all of his patients.



Frank Alexopoulos, P.A.

Physician Assistant

Frank Alexopoulos earned his Physician Assistant degree from Long Island University/The Brooklyn Hospital Center.  He is board certified by the National Commission on Certification of Physician Assistants and has been practicing dermatology for 14 years. Frank provides general and surgical dermatologic procedures and is licensed to practice medicine as a Physician Assistant in the States of New York and Florida.  He is affiliated with Mount Sinai Hospital and the dermatology departments of Elmhurst Hospital Center and Queens Hospital Center.  He is a member of the Society of Dermatology Physician Assistants, the American Academy of Physician Assistants, and the New York State Society of Physician Assistants


Jennifer Kallio

Physician Assistant

Jennifer is originally from St. Petersburg, Florida. She attended the University of Florida where she received her Bachelor of Science (BS) in Food Science and Human Nutrition with a specialty in Dietetics and also completed a Dietician internship in Manhattan at New York Institute of Technology. Jennifer then went on to Nova Southeastern University where she received a Bachelor of Science (BS) in Physician Assistant studies and a Master in Medical Science (MMS). Upon graduation, Jennifer worked in Pediatrics, Family Practice and has now spent the last 13 years working in Dermatology. 

Jennifer provides general dermatology care for patients of all ages. This includes acne treatment, skin care screenings, mole evaluations and many other common dermatology conditions. Jennifer also specializes in the diagnosis and management of psoriasis, eczema, vitiligo and other skin conditions which require ultra violet light and other cutting edge treatments. She also has received specialized training in surgical assisting / suturing for skin cancer (MOHS) surgery. She can perform biopsies, cryosurgery along with minor surgical procedures. 

Along with helping patients with dermatology concerns, Jennifer also specializes in numerous cosmetic procedures.  She is able to treat sun/brown spots, melasma, hair removal, redness, rosacea and can consult on any anti-aging concerns. Jennifer is highly skilled in cosmetic injectables including Botox and fillers. 

Jennifer is a member of the American Academy of Physicians Assistants, Society of Dermatology Physician Assistants, New York Society of Dermatology Physicians Assistants, New York State Society of Physician Assistants and was formerly a member of the Florida Society of Dermatology Physician Assistants and was the local liaison for the Florida Academy of Physician Assistants. She is certified with the National Commission on Certification of Physician Assistants. PA Jennifer was a member of the Allergan Review Panel which took place in NYC and has also helped with organizing and worked at numerous Physician Assistant Conferences. Jennifer is also fluent is Sign Language. 

When Jennifer is not working she enjoys traveling, attending shows, reading, running and spending time with her husband and mini dachshund Bo.