What causes eczema or dermatitis?

Genetics allergies. People inherit the tendency toward allergic conditions as eczema. You have dry sensitive skin which loses water . Barrier creams such as eletone and hylatopic can be helpful in treating the condition.
Many causes . Can be caused by over-drying of the skin such as washing with hot water or using drying harsh soaps or chemicals, stress, heat or cold, change in weather or environment, allergies.