Traveling to Rome with nut allergies

Look at this thread for partial advice. https://community.ricksteves.com/travel-forum/italy/cinque-terre-with-a-nut-allergy

I'd simply print a warning note in Italian using one of the many sites. And eat at restaurants like thousands of people with allergies did before you.

Last time I checked there were no Nuts on Pizzas and most roman dishes. Avoid tourist traps and you will also Steer clear of Pesto.

I would write up something in Italian, and let them know if that includes pine nuts...pesto, you know. Also whether tree nuts or peanuts, or both. 'nut' has a broad definition, so be precise. Also, if severe, I am assuming this includes cross contamination or airborne flecks?
How do you deal with it at home?
have you read the numerous 'nut-free' blogs? https://emsnutfreeeats.com/allergy-friendly-restaurant-guide-rome/

Aren't nuts a common ingredient for Gelato [especially pistachio] as well as bakery products? So two classes of establishments to avoid?

Although most gelato flavors don't include nuts, I'd think cross-contamination could be an issue at gelato shops.

Another place to be careful is pastry shops (pasticcerie). I don't know how broadly it is used in Italian desserts, but Sicilian pastries are sometimes covered in marzipan (almond paste). There are no visible nuts; you might assume you're looking at some sort of hard frosting, but it could be marzipan. I'm afraid a careless employee, if asked about nut content, might not think immediately about the marzipan.

I was really impressed by how much American food allergies have affected labeling when we visited Rome. Many shops had warning labels about gluten, nuts, which sorbet flavors had dairy, etc. The problem you'll find is if your children are triggered by items made on machines that also process nuts. I would learn how to say your children have a life-threatening nut allergy and that you would like a clean serving spoon even for nut-free flavors.

I might spend some time on trip@dvisor searching for restaurants that accommodate nut allergy. A few of the restaurants near Pantheon advertised gluten free kitchens with separate pans, etc, and these same establishments had many of the major allergies listed upfront on their menus. Also, there are some excellent grocery stores with ready-to-go (take and heat) complete meals and
an upscale frozen section.

This blog may help you.

You will need to specify what nuts. My niece has a severe nut allergy but it doesn't include almonds so she is fine with marzipan which is good since almonds are quite common here. The more touristy places can accomodate you.

My daughter spent a month in Italy and did not have to spend it "living off cheese, fruit and canned food ..."

In addition to nut( all legumes) allergy, she cannot do seafood. She ate well.

Let the waiter know about the allergies or ask if any nut product is used in the prep of something.

You will need to specify what nuts

I'd stay on the safe side and use the Broader definition of "frutta con guscio" (that does not include legumes)

An effective card would say:

"I miei figli sono gravemente allergici a tutta la frutta con guscio, come ad esempio: noci, nocciole, pinoli e mandorle".