Webbing of the fingers and toes is called syndactyly. It refers to the connection of two or more fingers or toes. Webbing usually only involves a skin connection between the two areas, but in rare cases may involve the connection (fusion) of bones.
Syndactyly may be discovered during an examination of an infant or child. In its most common form, it is seen as webbing between the second and third toes. This form is often inherited and is not unusual. Syndactyly can also occur along with other birth defects involving the skull, face, and bones.
The web connections usually run up to the first joint of the finger or toe, but may run the entire length.
"Polysyndactyly" describes both webbing and the presence of an extra number of fingers or toes.
More common causes:
Very rare causes:
Cornelia de Lange syndrome
Use of the medication hydantoin during pregnancy (fetal hydantoin effect)
When to Contact a Medical Professional
This condition is normally discovered at birth and evaluated during the newborn hospital stay.
What to Expect at Your Office Visit
The health care provider will perform a physical exam and ask questions about the child's medical history. Questions may include:
Which fingers (toes) are involved?
Have any other family members had this problem?
What other symptoms or abnormalities are also present?
An infant with webbing may have other symptoms that together may be signs of one syndrome or condition. That condition is diagnosed based on a family history, medical history, and physical exam.
The following tests may be done:
Lab tests to check for certain proteins (enzymes) and metabolic problems
An orthopedic surgeon may perform surgery to separate the connected fingers or toes.
Carrigan RB. The upper limb. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 673.
John Goldenring, MD, MPH, JD, Pediatrician with the Sharp Rees-Stealy Medical Group, San Diego, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.