I described my situation in detail in my book,
Shaolin Trips. Basically, I was being treated at Shaolin, and had a tremendous reaction, which resulted in cellutis. It was pretty horrific, but fortunately it didn't manifest fully until I was leaving China. I had to go straight from SFO to the emergency room.
Therein lies one of the greatest hazards of dit da jow. It's completely unregulated, especially in America. TCMer could put rat **** in it and how would you know?
Now I get a reaction from a lot of topical liniments. For a while, I worked with a few TCM/Kung Fu people to try and identify what specifically I was allergic to, but it seems to be a gestalt of ingredients. So I abandoned dit da jow. If I need some sort of topical relief, there are so many other products for pain, soreness and bruising available - from Western scientifical stuff like Ben Gay, to classic herbal remedies like arnica blends, to aryuvedic recipes that are as venerated as dit da jow. I do miss dit da jow as that stuff was the bomb, but I had to move on.