A risk factor  is anything that increases a person's chance of developing a disease. Although risk factors often influence the development of mastocytosis, most do not directly cause the disorder. Some people with several risk factors never develop the mastocytosis, while others with no known risk factors do. However, knowing your risk factors and talking about them with your doctor may help you make more informed lifestyle and health care choices.
The following factors may raise a person's risk of developing mastocytosis:
Age. Most often, cutaneous mastocytosis begins during infancy and early childhood. The risk of developing mastocytosis also increases during middle age.
C-kit receptor mutation. The c-kit receptor is a protein on the surface of some cells that binds to stem cell factor (a substance that causes certain types of cells to grow). A mutation of c-kit may cause some types of mastocytosis.