Straightforward enough: does anyone know whether or not P.F. Chang’s uses MSG in their food preparation? The last three times we’ve had lunch there, my wife has been feeling unwell by bedtime; we just noticed the pattern last night, when she got violently ill & then felt better almost immediately afterwards. We both ate from the same dishes but I didn’t get sick, so I guess that rules out food-borne bacteria. We had the same thing for breakfast, too. She’s not especially aware of a MSG allergy, but what else can it be?
A second possibility might be sensitivity to niacin (either nicotinic acid or niacinamide). Most of the population experiences a sensation resembling a flush and a sense of having a mild fever after ingesting substantial niacin “in one fell swoop” (as, for example, in a high-mg niacin vitamin pill). Many of us, myself included, have a milder similar reaction to many Chinese dishes, apparently somehow connected to niacin concentration in soy (soy sauce, soy extract in the dish, or perhaps high-niacin foodstuffs) in many cases. The few times we’ve eaten at the local P.F. Chang’s, I did not experience this, but I’ve had it happen with a wide variety of other Chinese dishes. It is for me merely a mild discomfort that passes away fairly quickly (~15 minutes). But it’s a possibility she may want to check out.
There are also lots of people out there with food sensitivities you might never expect. In many occasions a coloring or seasoning could be the culprit and you are not even aware of the problem because you are not associating the proper compnent of the dish with the discomfort. It took me about 3 visits to figure out something in the dollar menu chicken sandwitches at jack in the box was giving me violent headaches about an hour after eating them.