What, in your opinion, causes eczema?

Hi, For most of my childhood, i suffered from extreme eczema that made me spend my time in hospital getting bandaged. Thankfully, the condition eased when i was 10 years old. But my eczema is still there. I have found that certain foods ( seafood, nuts, fried food) cause it to come back. Also, when it is too warm or too cold, it comes back as well. I would like to know if this happens to anyone else? Also, what factors cause your skin to inflame and itch like mine? ( so i don't risk anything) Just curious as people think i exaggerate when i tell them i can't eat certain foods and i would just like some back up on this.I.e. If i'm being melodramatic or not. Thanks!