How come I have tinea, but nobody else in the family has it?

Common infection. Tinea is a common fungal infection of the skin. It can be transferred from surfaces (showers, floors, towels) or from one place on your skin to another. It is unusual to see this type of skin infection spread throughout a family. It is easily treated in most cases. Other skin conditions can look similar, though, so if it is not responding to treatment, you should see a dermatologist.