Eli5: As somebody with eczema, why can’t dry skin just be rehydrated by water, why does water make it worse, especially hot water I’ve been told

Question

I get really bad eczema on my hands, and the doctors tell me I wash my hands too much, never knew that was a thing but I work in a restaurant so don’t really have a choice. But I just don’t understand why we need lotion or prescribed ointment, why can’t I just skin my hand in a tub of water for an hour and bam hydrated.

In: Biology

Answer 1

Oil (commercial moisturizer for example) hydrates. Water washes away the oil, thereby drying the skin.