Husband started trazodone 50mg a month and a half ago. About two weeks ago he started having swelling of lips and chin. We narrowed it down to carrageenan an additive in coffee creamer ( he's never had a reaction before to coffee creamer before) gave him 10 ml benadryl swelling went away he'not drinking coffee 2 weeks later his cheek and lip are slightly swollen again today gave him 10 ml of benadryl and muscle tighting in right arm for over a week.he's 67. Would it taken this long for an allergic reaction to happen. And why two weeks between swelling reactions