My 9 year old son has a rash on his right wrist and left elbow bend. it came on then subsided. it is back. it is very itchy.

Eczema possibly: Due to location and itching and on and off most likely eczema, but hard to tell without seeing it. i suggested making a consult and we can help you. In general for eczema use fragrance free products (detergents, shampoo, soap), no softeners, use moisturizer every day (fragrance free) and a steroid cream can help on the patch that is worse, but i would suggest a consult to verify it is eczema.