As the parent of a child with a severe, life-threatening peanut allergy, these treatments could be a Godsend. It's hard to describe the life change that occurs when a normal food like peanuts suddenly becomes a disguised killer that could take my child away at any moment. The speed with which it strikes is stunning; according to our allergist, we have only minutes to administer EpiPens to avoid the runaway anaphylact…
While I appreciate your concern and caution, I feel like the medical community has worked the public into a bit of hysteria over peanut allergies. So few people die from peanut allergies each year it's hard to actually get good numbers on the phenomenon. And yet I have several friends who report having someone deathly allergic to peanuts in their family. It seems incongruent.
In all seriousness, the best bet for concerned people is to see the doc and get tested. Our kid's reaction to the prick test was ~10x the normal "allergy" reaction - the doc immediately stopped the test and gave him medicine. (As mentioned elsewhere, kids do grow out of the allergy so it's important to retest!)
According to our allergist, the problem with peanut allergies in particular is that the reaction can vary dramatically for the same person. Ingesting it one time may cause nothing but hives, whereas another will result in throat constriction within minutes. Cue the news stories where people with seemingly minor allergies are suddenly in the hospital. For example, recently a girl in CA with a known allergy took a bite of a peanut butter brownie and then spit it out. Her parent, who was a doctor, waited 20 min to administer the EpiPen. She died.
(Disclaimer: not a doctor, probably didn't remember everything right, etc.)