Disclaimer: I am not a doctor, and I do not have eczema. The only medical advice I give is that everyone should get medical advice.

Having said that, time to time I get a skin condition of various types. You need to carefully analyse it. Only patient can do this self debugging.

Some pointers:

Check his blood glucose right at the onset of his flare-up.

Take an antiworm medicine and see.

Take a broad-spectrum antiviral and check.

Take an antiprotozoal( anti-amoeba) pill and check.

Add neem oil to the bath water and check. Better yet, take neem oil capsules and try.

Now..

He might be having a cytokine storm of sorts.. so take an immunosuppressant and check. How do you get the doc to prescribe this - don't know. Tell him it is for science.

There are some good herbs-

Aloevera Tinosporia Cordifolia Acalypha indica Datura Caltropis

The last two or quite toxic. Even herbals must be taken under a qualified doctor.

You know sometimes it is just water. Check it. Also wash the shadows :-) the shadows habor bad stuff and it spreads.

Finally Borax. Use a cup of this in bath..

Now some science. Consume any plant that has protease or protinease inhibitors. These plants are basically biotoxic. They protect themselves from pests using pi. If we eat them we can become cytotoxic. It will protect us from bad guys too as long as it does not spiral into a cytotoxic storm.

Good luck..

Remember: I am not a doc. Not even a quack. I hack for a living.