Anything that causes an instant 'reaction' whether it be a rash/hives, sneezing/itching, wheezing/asthma, watery eyes/rhinitis is considered an allergic reaction as it involves the immune system reacting to an allergen - whatever that allergen may be.
Anaphylaxis is a rarer reaction but the problem with allergies is that that can often accelerate without warning, and whereas something is considered mild, it can escalate in severity with the next exposure without any forewarning.
Any allergy - however mild, can be very irritating and distressing for the person suffering so I think its a little unfair to dismiss it so readily.
I wasnt aware of the nut advice when pg with my DD so continued to eat peanuts. DD was born with cows milk protein allergy and it also transpired she has a peanut allergy. As she has got older the cows milk protein allergy has reduced in its reactivity, but she has developed other allergies to 'general' things (cats/dogs/dustmite) along the way.
We have been fortunate enough to have a paediatrician at our local hospital (which has recently been under threat of closure), who happens to specialise in allergies. He has been pretty good, and acknowledges that there isnt enough known about allergies (difficult to research).
The best way to identify allergies is through blood tests, but most practitioners do not readily put people forward for these, and will tend to hand out steroids, inhaled/snorted or otherwise, rather than investigate the cause. If someone knew that cows milk protein allergy was the underlying cause of their skin condition/asthma or whatever, they could easily avoid it.
Food packaging is in dire need of shaking up.
Tesco's for example, will only vaguely label their products as "may contain traces of nuts" because it acts as a pretty good disclaimer and negates the need for their factories to be audited properly for presence of nut products.
This means that most foods from Tescos cannot be had by DD "just in case". Total nightmare.
Sainsburys is far better with labelling, and so we continue to shop there. It also provides a far better range of "Free from" type products.
Marks and Spencer are also pretty good.
It's an absolute nightmare.