Is there any link between what we eat and getting itchy skin and eczema ?

Certainly some people experience skin reactions related to certain components of their diet. The commonest manifestations are swelling and utricarial reactions (like nettle rash), but eczema can also be triggered this way. If the case is severe then it is probably sensible for a sufferer to undergo sensitivity or "prick" testing whereby a small amount of different potential allergens are left in contact with the skin surface to see which ones provoke a red "flare" reaction consistent with an allergic response. Food items containing that allergen can then be avoided, which can help to improve skin symptoms. But in mild cases full scale sensitivity testing like this is probably not necessary. Instead a "trial and error" approach can be used, with possible causative food items being eliminated from the diet one at a time. If after a certain food is withdrawn the symptoms improve this substance may be the culprit. To find out for sure, reintroduce the item to see whether the skin symptoms return.