Ectopic nail, also known as onychoheterotopia, is a rare condition where the nail grows in other places than the nail bed. This can affect both fingernail and toenails.
Majority of cases are congenital which means the individual is born with the condition. When congenital the ectopic nail typically grows alongside the original nail or is a small offshoot of the normal nail. It may also grow on the underside (palm side) of the finger/toe. In some cases an ectopic nail is acquired, which means it is caused by some environmental influence. In this situation a single, severe injury or repeated injury to the nail bed can cause abnormal nail growth. This is known as posttraumatic ectopic nail and the nail typically grows on the dorsal (top side) of the finger/toe.
Most cases of an ectopic nail do not cause problems but can lead to improper growth of the normal nail upwards instead of out, pain, inflammation, and infection.
An ectopic nail is diagnosed based on physical exam and looking at a small piece of the nail under the microscope to make sure it is nail tissue and not something else.
The treatment for ectopic nail is surgery to remove all the inappropriate nail tissue. If you or your child has been diagnosed with ectopic fingernail, talk to your doctor about current treatment options.
Description Last Updated: Apr 06, 2018