What is a pilomatricoma?

Pilomatricoma or pilomatrixoma is a benign (non-cancerous) bump under the skin.

It usually forms on the head or neck of school-aged children, but can grow anywhere on the body. Typically, only one pilomatricoma forms at a time. Some people are prone to getting them and may get several at one time or over their lifetime.

WHAT CAUSES IT?

Pilomatricomas grow from cells in the hair follicle (where the hair forms). The exact cause of pilomatricomas is not known. Some people have an injury or irritation at the site before the pilomatricoma forms.

WHAT DOES IT LOOK LIKE?

Pilomatricomas are often more easily felt than seen because they are under the skin. They feel like a small, hard lump (like a pebble) under the skin. The skin over the lump looks normal or can be a purple or blueish color. If the pilomatricoma becomes irritated, it can appear red or swollen. Pilomatricomas can be tender to touch, but usually do not cause a lot of pain or other problems.

HOW IS A PILOMATRICOMA DIAGNOSED?

Your doctor or provider can diagnose a pilomatricoma with a physical examination. A biopsy can be done to confirm the diagnosis, but is often not needed.

WHAT DO I DO IF MY CHILD’S PILOMATRICOMA IS PAINFUL?

Your child should be seen by a provider if the pilomatricoma becomes painful, red, swollen, or is growing very quickly.

WHAT IS THE TREATMENT FOR A PILOMATRICOMA?

Pilomatricomas do not usually go away on their own. They can slowly grow over time. If needed, pilomatricomas can be removed with a minor surgery. The surgery leaves a small scar.

THE DECISION TO REMOVE A PILOMATRICOMA DEPENDS ON:

  • How old your child is
  • How well your child can sit still for a short procedure
  • How much the pilomatricoma bothers your child

© 2016 The Society for Pediatric Dermatology