He would take the childrens formula and you need the adult formula - both of you can use the cream for the itching.
Parasite testing is very unreliable and very expensive. I have had customers send actual parasites to labs and the results come back negative.
My advice has always been to just parsite cleanse at least 2 times a year - whether you think you have parasites or not. If you do have parasites - you will get rid of them - if you don't, you will be protected from them infecting you in the first place.
Parasite cleansing will not hurt you - but leaving the parasites in your body will cause all sorts of problems.