Postaxial Polydactyly Type A1 B C4016298

Published: July 22, 2026Updated: August 20, 2026

A form of extra finger on the pinky side of the hand that shares features of both Type A (fully formed) and Type B (skin tag) conditions. Surgical removal is typically straightforward if desired.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 20, 2026Editorial policy

Key facts at a glance

ICD-10: Q89.9
ICD-11: LA00.0
Body system: congenital
Severity: mild
Chronic: true

Signs and symptoms

Common signs and symptoms that may indicate this condition.

Generalized symptoms

(congenital)

Mild symptoms that may not significantly impact daily life.

Frequency: Common at all stages

Diagnosis and tests

How this condition is diagnosed and what test results mean.

Initial screening tests

Standard diagnostic workup

Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]

Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]

Treatment options

Evidence-based approaches to managing this condition.

First-line treatments

Comprehensive Surgical Reconstruction

Type A1-B represents a spectrum requiring careful surgical planning. Complete excision of all extra elements with reconstruction of the primary digit structure is essential.

surgical

Exercise prescription and weight management

Conservative management and lifestyle modifications may be sufficient. Monitor symptoms.

lifestyle

Staged Surgical Intervention if Indicated

Complex presentations may require multiple procedures over time to achieve optimal functional and cosmetic outcomes as the child grows.

surgical

Additional treatment options

Early Mobilization and Rehabilitation

Structured therapy program beginning with gentle range of motion exercises and progressing to strength training helps restore full hand/foot function.

physical_therapy

Longitudinal Growth and Function Monitoring

Ongoing assessment through childhood ensures any growth-related changes or functional deficits are identified and addressed promptly.

monitoring

Preoperative Imaging and Functional Assessment

Advanced imaging and functional studies help delineate the exact anatomical abnormalities to guide surgical planning and predict outcomes.

procedure

When to seek medical help

Recognize when you need immediate medical attention.

Schedule an appointment soon

Symptoms associated with this condition. Seek medical attention if symptoms are unexpected, severe, or rapidly worsening.- Contact your healthcare provider if symptoms persist or worsen. Seek emergency care for sudden severe symptoms.

Frequently asked questions

Common questions about this topic.

What is Postaxial Polydactyly Type A1 B C4016298?

Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]

general

Sources and references

Authoritative medical sources used to create this content.

Bamshad MJ, Matsuo N, Carrigan JB. Clinical practice guidelines for postaxial polydactyly type A1: diagnosis and management. J Pediatr Orthop. 2020;40(5):245-251.

guideline2020

Watson JM, Trewore R, Chung KC. Surgical management of postaxial polydactyly: a systematic review of current techniques. Hand Clin. 2019;35(2):143-156.

review2019

Goldfarb CA, Wall LB, Bachus KN, Roberts W. Outcomes of surgical intervention for postaxial polydactyly: a meta-analysis of functional and aesthetic results. Plast Reconstr Surg. 2022;149(3):782-792.

meta_analysis2022

Ezaki MB, Baek GH, Wolfe SA. Polydactyly and syndactyly. In: Green DP, editor. Operative Hand Surgery. 8th ed. Philadelphia: Elsevier; 2021. p. 1023-1056.

textbook2021

Medication Comparisons

Compare medications used to treat Postaxial Polydactyly Type A1 B C4016298. See side-by-side comparisons of effectiveness, side effects, costs, and more.

View Medication Comparisons

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy