Here's a story on Eater: How Chefs With Food Allergies Make It Work.

Orgeat:

The biggest takeaway from her allergy has been discovering just how poorly the hospitality industry still handles them. She’s had incidents where she’s been assured by waitstaff that her meal didn’t have nuts, only to find out that an ingredient like orgeat (an almond-based syrup) had been used in her cocktail. But she says people are more understanding than they used to be.

The most common food allergies:

the eight most common food allergens: Milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, and soybean account for 90 percent of all food allergies in the United States.

About the realities of living and working with allergies:

Back when she still worked in kitchens, Selengut says that “other than peanut or something, we didn’t really believe in allergies.” Unfortunately, change has not been uniform in the industry, and while kitchens are better at taking allergies seriously, she still regularly finds garlic in her food when she goes out to eat. The only way to make things better, Selengut says, is to have “a serious overhaul of quality control and management from the chef de cuisine to the busser.”

It would be interesting to hear from some bartenders with food allergies.