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Supernumerary Digit Clinical Presentation

  • Author: Luke Lennox, MD; Chief Editor: Dirk M Elston, MD  more...
Updated: Mar 29, 2016


Polydactyly is the most common congenital digital anomaly of the hand and foot. It may appear in isolation or in association with other birth defects.[8]



Temtamy and McKusick[9] classified polydactyly into preaxial, central, and postaxial types. Preaxial polydactyly refers to the duplication of the first digit. Central polydactyly involves duplication of the second, third, or fourth digit. Postaxial polydactyly involves the fifth digit. The terms radial, central, and ulnar can be used to describe polydactyly in the upper extremity. Similarly, the terms tibial, central, and fibular can be used to describe polydactyly in the lower extremity.

The association of hand and foot polydactyly is uncommon. If hand and foot polydactyly does occur, it may be a case of "crossed polydactyly"—when preaxial involement of the hand and postaxial involvement of the foot occurs or vice versa.

Synpolydactyly is the combination of syndactyly and polydactyly.[10, 11]



See Pathophysiology.

Contributor Information and Disclosures

Luke Lennox, MD Resident Physician, Department of Medicine, University of Buffalo, State University of New York School of Medicine and Biomedical Sciences

Disclosure: Nothing to disclose.


Thomas N Helm, MD Clinical Professor of Dermatology and Pathology, University of Buffalo, State University of New York School of Medicine and Biomedical Sciences; Director, Buffalo Medical Group Dermatopathology Laboratory

Thomas N Helm, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American Society for Dermatologic Surgery, American Society of Dermatopathology

Disclosure: Nothing to disclose.

Specialty Editor Board

Richard P Vinson, MD Assistant Clinical Professor, Department of Dermatology, Texas Tech University Health Sciences Center, Paul L Foster School of Medicine; Consulting Staff, Mountain View Dermatology, PA

Richard P Vinson, MD is a member of the following medical societies: American Academy of Dermatology, Texas Medical Association, Association of Military Dermatologists, Texas Dermatological Society

Disclosure: Nothing to disclose.

Robert A Schwartz, MD, MPH Professor and Head of Dermatology, Professor of Pathology, Pediatrics, Medicine, and Preventive Medicine and Community Health, Rutgers New Jersey Medical School; Visiting Professor, Rutgers University School of Public Affairs and Administration

Robert A Schwartz, MD, MPH is a member of the following medical societies: Alpha Omega Alpha, New York Academy of Medicine, American Academy of Dermatology, American College of Physicians, Sigma Xi

Disclosure: Nothing to disclose.

Chief Editor

Dirk M Elston, MD Professor and Chairman, Department of Dermatology and Dermatologic Surgery, Medical University of South Carolina College of Medicine

Dirk M Elston, MD is a member of the following medical societies: American Academy of Dermatology

Disclosure: Nothing to disclose.

Additional Contributors

Albert C Yan, MD Section Chief, Associate Professor, Department of Pediatrics, Section of Dermatology, Children's Hospital of Philadelphia and University of Pennsylvania School of Medicine

Albert C Yan, MD is a member of the following medical societies: American Academy of Dermatology, Society for Investigative Dermatology, Society for Pediatric Dermatology, American Academy of Pediatrics

Disclosure: Nothing to disclose.

Carter G Abel, MD Clinical Assistant Attending, Department of Dermatology, New York Presbyterian Hospital

Carter G Abel, MD is a member of the following medical societies: American Academy of Dermatology, American College of Mohs Surgery, American Society for Dermatologic Surgery, Medical Society of New Jersey

Disclosure: Nothing to disclose.

Denise M McCarthy, MD Associate Professor, Department of Radiology, Morristown Memorial Hospital

Denise M McCarthy, MD is a member of the following medical societies: American Association for Women Radiologists, American Roentgen Ray Society, Association of University Radiologists, Radiological Society of North America

Disclosure: Nothing to disclose.

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Twenty-eight-day-old supernumerary digit, rudimentary nail unit cartilage (2x).
Twenty-eight-day-old supernumerary digit, nerve bundle base (40x).
Twenty-eight-day-old supernumerary digit, connective tissue and epidermis (40x).
Supernumerary digit, no magnification.
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