Eczema has two major causes. The first is called atopic eczema, which is a result of a problem from within the body. The second is called contact dermatitis, which is caused by a substance outside of the body, according to Patient.co.uk.
People with atopic eczema sometimes have flareups of a rash or itchiness with no identifiable cause, notes Patient.co.uk. However, the flareup can sometimes result from an infection or stress. External causes of eczema include contact with certain types of clothing or materials, toiletries and perfumes or even a reaction to the temperature. Treatments include corticosteroids, antihistamines and immune modulators, explains WebMD.