For example, I am highly allergic to fish oil. I cannot touch fish oil in any way or I have a "simple" allergic reaction where my hands get numb, red and itch like crazy. I have a big problem if I were to ingest fish or fish oil in any way, shape or form. I would have to get to the hospital quick in that case. I also am unable to be in the same room where it is being cooked or I start to sneeze and my eyes water, get red and itch. I can eat Shellfish though!! :D My parents use to joke that I had expensive tastes.
Ever thought about wanting to just go to church and being unable to because of an allergy? Well my mother has to think of this. She is highly allergic to smells and can get migraines because of them. She is unable to even attend church because of the perfume that people wear and shopping is a literal migraine inducing nightmare because of the perfumes, candles, and other strong smells
Another allergy that can be this severe is Peanuts or Nuts. Although Peanuts are not in the nut family, people can be allergic to both and this allergy (I have always heard) is almost always extreme. Children could have an allergic reaction from even, say, touching a door handle where someone who has just eaten PBJ sandwiches has touched.
I have heard about two specific people with these kinds of allergies in just the last couple of weeks. One story was heart warming for the way that people were helping to get Fletcher for Bailee. Fletcher is an allergen alert dog that was picked for this beautiful little girl. The other was how some cruel kids nearly killed a classmate with a severe nut allergy in Sweden. Two extremes on the emotion scale and two ways of thinking.
I don't know about anyone else, but I want to understand and help people who have extreme allergies such as these. I would love to find some books that have real world problems that the characters deal with if anyone has any recommendations. :D