| Birthmark | |
|---|---|
 | |
| Mongolian spot visible on six-month-old baby | |
| Specialty | Dermatology |
A birthmark is a congenital, benign irregularity on the skin which is present at birth or appears shortly after birth—usually in the first month. Birthmarks can occur anywhere on the skin.[1] They are caused by overgrowth of blood vessels, melanocytes, smooth muscle, fat, fibroblasts, or keratinocytes.
Dermatologists divide birthmarks into two types: pigmented birthmarks and vascular birthmarks. Pigmented birthmarks caused by excess skin pigment cells include: moles, café au lait spots, and Mongolian spots. Vascular birthmarks, also called red birthmarks, are caused by increased blood vessels and include macular stains (salmon patches), hemangiomas, and port-wine stains. A little over 1 in 10 babies have a vascular birthmark present by age 1.[2] Several birthmark types are part of the group of skin lesions known as nevi or naevi, which is Latin for "birthmarks".
Birthmarks occur as a result of a localized imbalance in factors controlling the development and migration of skin cells. In addition, it is known that vascular birthmarks are not hereditary.[2][3]
- ^ "birthmark" at Dorland's Medical Dictionary
- ^ a b "Birthmarks". American Academy of Dermatology. Archived from the original on 2009-11-08. Retrieved 2011-06-20.
- ^ "Birthmarks". Seattle Children's Hospital and Regional Medical Center. Archived from the original on 2017-02-02. Retrieved 2008-08-02.