Hennessey, Patrick, M.D.

Compassionate healthcare is how we describe our 36 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.

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.

Dr. Mark A. Halsey, MD is a double board-certified dermatologist practicing general, cosmetic, and pediatric dermatology in the Hamptons. Dr. Halsey received his undergraduate degree from the Massachusetts Institute of Technology. He graduated from the University of South Florida College of Medicine, where he was a member of the Alpha Omega Alpha medical honor society, and served as president of his medical school class. He completed his internship at the world-renowned Massachusetts General Hospital (Harvard Medical School), followed by dermatology residency at the University of Massachusetts, where he served as Chief Resident in his final year. He then completed additional training in pediatric dermatology at Boston Children’s Hospital (Harvard Medical School, Dept. of Dermatology) to obtain a second board certification in pediatric dermatology. He completed the American Society of Dermatologic Surgery Preceptorship program to gain additional expertise in cosmetic dermatology, and minimally invasive procedures of the skin.

Dr. Halsey is a Diplomate of the American Board of Dermatology, with dual board certifications in Dermatology and Pediatric Dermatology. Dr. Halsey serves as an Assistant Clinical Professor at NYU, where he has taught residents and medical students since 2016. He maintains a clinically focused and patient-centered practice.

Mark Halsey has deep ties to the South Fork, with family living in the Hamptons for the past 13 generations. He lives in Bridgehampton, with his wife, June, and his son.

Michael Ferranti is a certified Physician Assistant specializing in cosmetic, laser, general/surgical dermatology and STD medicine. He has been practicing as a P.A. since graduating Hahnemann University. He has worked in dermatology for the past 15 years. Past specialties include internal medicine, emergency medicine, family medicine, and oncology. In 1997, Michael also helped to start and accredit the Lenox Hill Hospital/Pace University Physician Assistant Program and still an adjunct professor. 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.

117 East 18th Street.
New York, NY
New York