Strawberry birthmarks are raised, soft red lumps on the skin. They are found on at least one in fifty babies and are the most common benign tumor in infants. Many myths have developed about these birthmarks. For example, if a pregnant woman does not satisfy a sudden wish for strawberries, it's said that the infant might bear a strawberry mark... But even today, the cause of birthmarks is not fully understood.
What are the different types of birthmarks?
There are two main categories of birthmarks: red birthmarks and pigmented birthmarks. Most birthmarks are not inherited. A birthmark comes from an overproduction of coloring of the melanocytes, which are the cells responsible for skin pigmentation. Red birthmarks are colored, blood vessel (vascular) skin markings that develop before or shortly after birth.
The most common types of red birthmarks are:
- Strawberry birthmark (has a raised red surface)
- Portwine birthmark (lies flat against the skin)
- Hemangiomas (have a reddish color are are usually present at birth or within a few months later)
- Salmon patches or stork bites (pink and flat) - extremely common, appearing on 30-50% of newborns.
Pigmented birthmarks are:
- Mongolian spots (usually bluish and appear as bruises)
- Moles (growths on the skin that usually are flesh-colored, brown or black)
- Congenital nevi (a brown to brownish black mark that is present at birth)
- Cafe-au-Lait Spots (light tan or light brown spots that are usually oval in shape)
Infants born with strawberry birthmarks: a genetic cause?
Strawberry birthmarks in infants, also called infantile hemangiomas, is due to an over growth of blood cells during development of the fetus. They are thought to occur as a result of a localized imbalance in factors controlling the development of blood vessels. This profileration of blood cells results in the red color.
Some birthmarks seem to have a genetic connection as other members of the family may have the same birthmarks. But strawberry birthmarks are not usually hereditary, although 10% of infants have a family history of these vascular birthmarks.
Any correlation between premature infants and birthmarks?
Are premature infants more likely to have strawberries birthmarks than babies born at term? A study by researchers at The Medical College of Wisconsin and Children's Research Institute shows that low birth weight is the most significant factor for the development of infantile hemangiomas.
"This study reaffirms several known risk factors for infantile hemangiomas, specifically female gender, white, non-Hispanic race/ethnicity, and prematurity," says Dr. Drolet who led the study. "The link to low birth weight may explain why physicians believe more infants are developing hemangiomas. Based on low birth weight statistics, we estimate that the incidence of infantile hemangiomas has increased by 40 percent in the last 20 years."
Are there other possible causes for strawberry birthmarks in infants?
Another study, also published in Pediatric Dermatology Journal, reveals that a disturbance of oxygen depletion was found in placentas of babies who developed infantile hemangioma. The researchers concluded that disturbed placental circulation is a factor underlying the development of hemangiomas in very low weight newborns and indicates that placental examination is essential for clarifying the physiologic changes leading to strawberry birthmarks in babies with normal birth weight.
More research is needed to determine the real cause of strawberry birthmarks. However, it is believed that no known food, medication, or activity during pregnancy can cause a hemangioma. So, parents shouln't feel guilty. It is natural to feel upset or worried, but birthmarks are not linked to anything the mother did during pregnancy.
Also, strawberry birthmarks tend to fade spontaneously. They are neither painful or harmful, although about one in a hundred will require medical treatment. So, it is still recommended to consult a doctor who will also evaluate and possible recommend some x-rays to see the extent of an infant strawberry birthmark.