Formula and eczema

So my son was born prematurely and never had the strength to breastfeed so for the first 3 and a half months he was exclusively ebf. Then it became a lot as I felt he needed more so I moved to mixed ebf and formula but he started gaining weight and sleeping better on the formula so by 4 months he was on only formula now at 7 months he has horrible eczema and when I look back it seemed to start when I introduced formula and now he is on the progress stage it is really bad.

Has anybody else has a reaction similar??