My Husband Is Suffering With Incredible Itching On His Instepes

My husband is suffering with incredible itching on his instepes and arms and red raw weeping on his feet muscle tested him and seems to be at the moment allergic to sofa,car seat and chair from where he spends a lot of time siting for work,I'm thinking maybe he's allergic to formaldehyde, so covered everything with a natural non bleached cotton sheet at first it seemed to alleviate it but stil has a lot of itching.
So bought trigentax today to see will it help.
Would really like to know what could be causing his problem.