From what I understand a dystonic reaction and chronic dystonia are two different things. Although chronic dystonia can certainly happen after just one exposure to an offending med and a dystonic reaction. That is not always the case. I think there are some meds that cause dystonic reactions in a large percentage of people, but most do not develop dystonia as a chronic condition.Years ago, before I had symptoms of dystonia, I had a dystonic reaction to Compazine, which is an anti-psychotic that is frequently used in ERs because it stops vomiting. I had a dystonic reaction and went through the whole benadryl/muscle relaxant thing and was fine after that. I only developed chronic dystonia symptoms after taking another med for a couple of years.
Some doctors/researchers will tell you that a dystonic reaction does not indicate that you are more likely to get chronic dystonia from another med; all it means is that you say away from the med that gave you the reaction and anything similar. Others say that people who have dystonic reactions are more sensitive to getting the chronic condition, even to meds that only rarely cause it. I'm not a medical professional so I don't know which statement is true.
My guess is that if you're fine now after the course of benadryl, then you will continue to be fine. Just to be on the safe-side, stay away from drugs known to cause those reactions. I know people have posted a link to a site that lists those drugs. You could do a search for it or maybe someone who has the link will post it again.
Good Luck!
