DermNet NZ

Facts about the skin from DermNet New Zealand Trust. Topic index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Fistulas and sinuses of the neck and face

What is a fistula and a sinus?

A fistula is an abnormal channel leading between two cavities or surfaces which may drain a fluid material such as saliva or pus. An example would be from the mouth (oral cavity) to the skin surface, usually of the face or neck, and this specific type is called an orocutaneous fistula.

A sinus has one open draining end and the channel ends in a blind ending. An example would be a dental sinus draining from a dental abscess to either the inside of the mouth or the skin.

The words however are often used interchangeably.

Fistulas and sinuses of the neck and face: classification

Fistulas and sinuses of the neck and face may be classified by cause.


Fistulas and sinuses due to developmental causes are usually present at birth.

Preauricular pit Preauricular sinus
Preauricular sinus


Cysts are lumps in the skin containing fluctuant contents. They may have an opening to the skin surface.

Epidermal cyst
Epidermal cyst showing opening to external skin



Lymph node

Scrofuloderma Scrofuloderma


How is a fistula or sinus diagnosed?

In addition to careful history and examination, one or more of the following tests will usually be required to confirm the diagnosis and determine the cause:

  1. passing a probe into the channel
  2. radiology – may include plain x-rays, x-rays using contrast medium, CT or MRI scans
  3. microbiological assessment of swabs or biopsy material
  4. biopsy and pathology

Treatment of a fistula or sinus

This will be determined by the specific cause.

Related information


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Author: Dr Delwyn Dyall-Smith FACD, Dermatologist

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