I've had eczema since I was 1 years old. I took steroids and various topical creams until I was 22 thinking it was helping make me better. Taking stronger and stronger steroids until one day they just stopped worked. I broke out in a 2 year long nasty rash that just wouldn't quit. It wasnt just the dry skin on my hands and arms that I was used too. It was everywhere, broken skin, bleeding, swollen and pussing.
I tried every diet (elimination, GF, dairy free, vegan, keto, paleo) and every topical treament (emuaid, silver, all natural, coconut oil, tea tree, baking soda, even bleach).
I finally sought out a kinesiologist for back pain I was having and they recommended I try intermittent fasting for my skin, saying it could be related to a weak stomach. Within 3 days of eating from only noon to 6 pm and drinking a gallon of water a day my skin started clearing up. After a week it was completely healed, leaving behind soft pink new skin.
So naturally I stopped fasting thinking I was cured. Within 2 days my skin started breaking out again. I started experimenting and noticed the longer I stuck to my fast the more frequently I could break it without seeing a change in my skin. For example, if I stuck to a healthy diet with lots of veggies and not a lot of sugar/alcohol/simple carbs and ate only 6 hours a day for a 7 day streak, I could have pizza and beer one night and not have a problem. If I ate clean and fasted for 2 weeks I could eat poorly for 2 days and not have a problem.
Now I aim to eat for 6-8 hours a day. Drinks lots of water. Eat a paleo focused diet. And I never have any problem with my skin. When I veer off the path too much, a long weekend of eating whatever and whenever I want, or a couple of days of non stop partying, my eczema starts to pop back up giving me a warning to get it together.
The cause of everyone's eczema is different. Just know that your skin is trying to tell you something. For me it was a weakened stomach lining. Fasting allows my body to focus on healing instead of digesting. If I have a bad breakout and an event coming up that I need clear skin for, I can fast for a full 24 hours and my skin will mostly clear up.
Always consult with your doctor before starting any form of fasting.