Preauricular pit
Also called: Preauricular sinus · Ear pit · Congenital auricular fistula
A tiny hole in the skin just in front of the ear, present from birth, that can lead to a tunnel under the skin. It is harmless unless it gets infected.
How common
Do you have this?
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 shape3. 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 face3. Under the skin the tract varies in length, and it can branch3. It can also lead to a small cyst3. The tract is an inward fold of skin4, so dead skin cells and other debris can build up inside it1.
The pit is present from birth. It can be on one side or both. It runs in families1. It is thought to be inherited in a dominant pattern with incomplete penetrance, meaning not everyone with the gene shows it4. How often it turns up also depends on ancestry1.
How common it is
Pits and skin tags in front of the ear are common in newborn babies, and a doctor usually finds them at the first well-baby visit5. The number of people with a pit is given as a range because it differs between populations. It is about 0.1–0.9% in the US, 0.9% in the UK, and 4–10% in Asia and parts of 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:
- turns red or swollen,
- becomes painful,
- leaks fluid or pus.
These signs mean the tract may be infected.
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.
Sources and further material
- Wikipedia Preauricular sinus and cyst
- Wikipedia Branchio-oto-renal syndrome The rare syndrome in which ear pits occur with hearing loss and kidney problems.
- NCBI Preauricular sinus: a novel approach Indian Journal of Otolaryngology and Head & Neck Surgery. Explains how the ear forms from six hillocks and where the pit usually sits.
- NCBI Preauricular Sinus: A Tale of Forgetful Rediscovery Cureus. History of the pit and its inheritance, which the paper says is still not fully known.
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Related oddities
Darwin's tubercle
A small bump on the folded rim of the ear, which Darwin thought was the leftover tip of a pointed ancestral ear. Between 10% and 58% of people have one, depending on the population.
Attached and free earlobes
Some earlobes hang free and others join the head directly. Textbooks taught this as one gene, but a 2017 study found at least 49 genetic regions involved, and the two shapes blend into each other.
Supernumerary nipples
An extra nipple, usually small and flat, on a line running from the armpit to the groin. Between 1 in 500 and 1 in 18 people have one, and it is often mistaken for a mole.