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PubMed This is a summary of 34 peer-reviewed journal articles Updated
Pediatrics

Postaxial Polydactyly Type B: A Guide for Parents

At a Glance

Postaxial polydactyly type B is a common, benign condition where a baby is born with a small extra finger or toe lacking bone structure, resembling a skin tag. It is usually an isolated finding that does not affect development and is effectively treated with a minor office-based procedure.

Finding out your baby has an extra finger or toe can be an unexpected and overwhelming experience. However, Postaxial Polydactyly Type B is a very common, benign condition that doctors often describe as a simple “skin tag” [1][2]. In the vast majority of cases, this is an isolated finding, meaning your baby is otherwise perfectly healthy and the extra digit has no impact on their overall development [3][1].

This guide is designed to help you understand your baby’s diagnosis, navigate the treatment options, and know what to expect as your child grows.

Resource Guide Index

01

Understanding Your Baby's Extra Digit: Postaxial Polydactyly Type B

Learn about postaxial polydactyly type B, a common condition where babies have a small extra finger or toe. Understand causes and safe removal options.

02

The Diagnostic Process: Distinguishing Type A vs. Type B

Learn how doctors diagnose postaxial polydactyly in babies. Understand the difference between Type A and Type B, why X-rays are needed, and when to test.

03

Treatment Options: Suture Ligation vs. Surgical Excision

Understand the treatment options for your baby's extra digit (Type B Polydactyly). Compare the pros and cons of suture ligation versus surgical excision.

04

Recovery and Long-Term Hand Function

Learn what to expect during recovery from Postaxial Polydactyly Type B removal. Understand your child's long-term hand function, wound care, and outcomes.

Common questions in this guide

What is postaxial polydactyly type B?
It is a common, benign condition where a baby is born with a small extra finger or toe. In type B, the extra digit does not have bone or joint connections and often resembles a skin tag.
Will my baby's extra finger or toe affect their development?
No. In the vast majority of cases, postaxial polydactyly type B is an isolated finding. The extra digit has no impact on your baby's overall health or long-term hand or foot function.
Why do doctors order an X-ray for an extra finger?
Doctors use X-rays to see if there is any bone or joint connection inside the extra digit. This helps them confirm whether it is type A (which contains bone) or type B (which does not), ensuring they choose the safest treatment.
How is postaxial polydactyly type B treated?
Treatment options typically include tying it off with a suture or performing a minor surgical excision. Modern pediatric guidelines generally prefer a quick surgical excision for better outcomes.
Can the extra digit be removed in the doctor's office?
Yes, many pediatricians and specialists perform surgical excision safely in the office without needing a hospital operating room. Your doctor will discuss whether an in-office procedure is appropriate for your baby.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.How many times have you treated Postaxial Polydactyly Type B in your practice?
  2. 2.Do you perform the preferred surgical excision in your office, or do you refer out to a pediatric orthopedic surgeon?
  3. 3.What specific signs or symptoms should prompt me to call your office after we go home?

Questions For You

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References

References (3)
  1. 1

    Polydactyly, postaxial, type B.

    Holmes LB, Nasri H, Hunt AT, et al.

    Birth defects research 2018; (110(2)):134-141 doi:10.1002/bdr2.1184.

    PMID: 29377639
  2. 2

    Isolated postaxial polydactyly: Epidemiologic characteristics from a multicenter birth defects study.

    Ortiz-Cruz G, Luna-Muñoz L, Arteaga-Vázquez J, Mutchinick OM

    American journal of medical genetics. Part A 2019; (179(8)):1432-1441 doi:10.1002/ajmg.a.61193.

    PMID: 31091006
  3. 3

    Predictors of Syndromic Association in Ulnar Polydactyly: Analysis of a Multicenter Congenital Hand Differences Registry in the United States.

    McQuillan T, Antonellis H, Wall L, et al.

    The Journal of hand surgery 2026; (51(3)):292-300 doi:10.1016/j.jhsa.2025.03.019.

    PMID: 40377505

This guide on postaxial polydactyly type B is for educational purposes only. Always consult your pediatrician or a pediatric orthopedic surgeon for medical advice and treatment decisions regarding your child.

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