Seborrheic keratoses: Who gets and causes

Who gets seborrheic keratoses?

The people most likely to develop these harmless growths have fair skin and family members who have seborrheic keratoses. These growths also develop in people with medium to dark skin. In dark skin, seborrheic keratoses tend to be small and appear around the eyes.

Some people develop seborrheic keratoses during pregnancy or after estrogen replacement therapy.

Most people develop seborrheic keratoses in middle age or later. The number of seborrheic keratoses tends to increase with age.

Children rarely have seborrheic keratoses.

What causes seborrheic keratoses?

The cause of seborrheic keratoses is unknown. We do know the following:

• Seborrheic keratoses seem to run in families. Some people seem to inherit a tendency to get many of these growths.

• The sun may play a role in causing seborrheic keratoses. Studies suggest that these growths develop on skin that's gotten lots of sun. Because these growths also develop on skin that's always covered, more research is needed.

• Seborrheic keratoses are not contagious. These growths may seem to multiply and spread to other parts of the body. What's really happening is that people get more of these growths as they age.