eczema versus psoriasis, The primary difference between psoriasis and eczema is the underlying cause. Psoriasis is an autoimmune condition, which means your immune system is malfunctioning and your skin cells are growing and multiplying too quickly. The cells begin to build up on the skin’s surface, generating the white scale.The etiology of eczema is significantly more intricate and difficult to pinpoint. Doctors at Kayakalp Global say that the rash could be caused by both genetic and environmental factors.