I underwent phototherapy for a few years and noticed a significant decrease in the severity of my eczema. Ultimately, I stopped going during the pandemic and have yet to restart due to the time commitment (driving, parking, waiting, therapy, etc.). When I was going, it was 2-3 times per week.
This is a treatment that should only be pursued under the care and supervision of a board certified dermatologist in a clinical setting. A tanning bed is NOT the same thing.
For more background on phototherapy, here is a link to an article on the Cleveland Clinic site.