Preauricular pit

How it works

The outer ear forms in the embryo from six small bumps of tissue, called hillocks, which grow together into the folded ear shape¹. If two of the hillocks fail to fuse fully, a small tract can be left behind. It opens as a pinhole in the skin, usually just in front of the upper rim of the ear where it meets the face¹. Under the skin the tract runs a few millimetres to a few centimetres and ends blind. It is lined with skin cells, so it can collect dead cells and oil like a pore¹.

The pit is present from birth. It can be on one side or both. It runs in families and is inherited in a dominant pattern with incomplete penetrance, meaning not everyone with the gene shows it¹.

How common it is depends on ancestry. Studies find it in under 1% of people in Europe and the United States, and in 4% to 10% in parts of Asia and Africa¹.

Is it a problem?

On its own, no. A pit that is dry, clean, and painless needs nothing and can be ignored for life. See a doctor if the pit becomes red, swollen, or painful, or if it leaks fluid or pus. That means the tract is infected. Infection is treated with antibiotics and sometimes drainage¹. Pits that get infected again and again can be removed by a small operation¹.

Rarely, a pit occurs together with hearing loss or kidney problems as part of branchio-oto-renal syndrome². Doctors who find a pit in a newborn sometimes check hearing for this reason. In a child who hears normally and has no other signs, a pit is simply a pit.

History and culture

Many people with a pit never notice it until someone else points it out. Online photo threads of ear pits are common, and most posters report finding it on themselves as adults.