My son eczema is so bad that his skin is all aver the house with him scratching what can I do to help him, can it be parasits?

Possibly. If your son truly has eczema, it is likely just eczema causing his miserable condition. It could possibly be parasites, or parasites on top of eczema. I have seen kids with both eczema and scabies and eczema and a bed bug infestation. It's best, that you get him re-evaluated since he is suffering so much.