Is an allergy causing vomiting following restaurant food?

Occasionally when I go out to a restaurant I get queasy and throw up within 15-20 minutes after eating. A couple times it has been at chain restaurants (Applebees, TGI Fridays) - most recently it was a Mexican restaurant, but I am no stranger to Mexican food. I don't over-eat, either.

Is this a food allergy, possibly? If so, is it important to figure out what the allergen is? I always feel fine after vomiting, and I have never been able to associate one particular food item as the trigger.

I do have acid reflux related to eating large amounts of dairy (and a couple of these visits I did have greasy food or cheese), but is throwing up a symptom of that? I'm fine with fast food.

The surefire way to determine food allergies is to keep a food diary, and start with one suspected food at a time, wait 24 hours, then proceed to the next suspected food. It takes time, but you should be able to hone in on the allergen. Yes, food allergies can cause vomiting. I've had food allergies all my life. If you can't find the source, you may not be allergic at all, but are having digestive issues with certain types of food, like you do with dairy.

if you want to eat out you need to figure it out, with my husband it was crustations. he was told it was chickengumbo but it turned out to be shrimp, yuck. also it could be that they arent washing the dishes well enough but that usually doesnt happen at all resturants or that quickly.

How much do you weigh, if your eating too much or too fatty of a food it can do it to you, im a 207lb guy and if i eat too much fatty food at once i feel nauseated and its not an allergy. Also did you have anything similar within the same meals?

Dont give up on restaurants once you figure it out. If you have an allergy just make sure your waiter knows so they can Special Instruction it out to the kitchen, and if not then Stay Away from the Fried Mac And Cheese, O its good going down, but its not good coming up.

Trust me i work at fridays.

*EDITED TO ADD*

The dishwashing machines at 90% of restaurants suck but i highly doubt thats the reason you are getting sick over and over again at many different restaurants.

Investigate the possibility of a mild reflux.