OK but a drupe is a botanical definition of the fruiting body. It does not seem to indicate any evolutionary proximity to other drupes. Dates should be more similar to coconuts than Almonds are. Of course that does not indicate the level of correlation between coconut and other "tree nut" allergies. I wonder if there is a statistic available? The correlation between treenut and peanut is very high, as is egg, but the correlation to legumes in general seems lower. I've seen no reasonable explanation of this either. Has anyone seen one? I imagine it has some connection to protein content and prevalence in our diets, but one would think there must be some other contributing factor as well.
Sorry for raising this, but I am trying to figure out how likely it is that my 3rd kids with NKA suddenly has a coconut allergy and nothing else.