Ive developed an intolerance to ibuprofen. get very hot/red, feels like fever after taking it. found out my mom was allergic to it. connection?

Side effect vs: allergy, you put it right, what you are experiencing can be a side effect to the drug , not a true allergy. What your mother had, could have been the same, or may be a true allergy. There could be a connection, but no direct relationship. You may want to avoid ibuprofen, probably all NSAIDS, but if taking it is a medical necessity, kindly see an allergist for evaluation, best wishes