Suggest Treatment For Allergy Causing Red Patches All Over Body

I am suffering elergic problem in whole body effected with red patches, ealier after my tkr i year before in both knees. I have start taking medrol cartisone for 7 days with the advise of local family doctor I got very good result but as soon as I stop taking cartisone the condition comes like before.Please advise me to I should consult in nagpur and what are the investigations which shold be done.with regards Anand ram Nankani age 86yr You can send me your valuable advise on email id of my son YYYY@YYYY