It's very possible to develop allergies from adrenal fatigue. I have seasonal allergies and I think it's related to adrenal fatigue because they have been less severe the more energetic I feel (which tells me I must be making more cortisol:-)
It's also possible to develop leaky gut and food sensitivities from adrenal fatigue. I don't have too many of those, thank goodness (just soy and certain dairy but not all dairy). I've reversed previous sensitivities (like wheat- not that I would eat that now, LOL!) but the dairy one remains, so I suspect it's more genetic.
BTW- I always felt worse in general after eating bananas. Not only is the sugar bad for adrenal fatigue but the potassium can be problematic, since the lack of aldosterone production lets potassium build up as sodium depletes. I was so happy to discover how helpful salty water on hot days was- I formerly would get heat-fatigued to the point of having to lay down to recover (I felt like SUCH a wuss!) but no more! Just give me some salty water with a twist of lime and I'm good!