Food allergy can be dangerous enough to kill your guest. Worldwide many people are allergic to food.
The key food allergens can be divided into a few food groups.
Once you have food containing items you are alergic to, then you need to get immediate medical supervision
Avoid food that are allergens and disclose all ingredients to guest who are allergic
Featured image courtesy: By NIAID – Peanuts, Egg, and Milk, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=82983913