Nut allergies are some way down the scale of lethality. The deadliest is probably anaphylaxis to dairy proteins, but it isn't often diagnosed until long after the funeral - not many people live into adulthood with it, and since dairy proteins are everywhere the cause is very hard to spot, it gets put down as idiopathic asthma until somebody else in the family gets the same thing. Then insect stings (often so catastrophic that an EpiPen will do nothing), and eggs - for a while the commonest diagnosed cause of death from allergy in the UK was children dying in the doctor's surgery from egg in allergy skin tests. (Allergy tests are not very safe - only get them done if you're sure you can make helpful use of the results).

For me, the wheat problem exacerbates pollen allergy. Either can make me sneeze, but pollen exposure after a slice of bread or an oatcake is ghastly. The label for this is "total allergic load" - many people can cope with one allergen at a time but not several at once.