4 year old with a mystery sleep condition ?

my daughter is 4 years old and for the past year has battling eczema and terrible break outs so our nights have been quite tough.
To top it off, we have something else happening and wonder if any other mums may know or experienced similar.
She first cries out gently she may be itchy or thirsty. Then she works herself up so quickly that phlegm builds up and oozes from her mouth and she chokes on it constantly drinking like she is severely dehydrated. Meanwhile the phlegm continues and then she throws tantrums by jumping up and down screaming her nose is running needs a tissue. She may even throw in there she is itchy and needs cream for her eczema. We sit with her with the water bottle and tissue til she calms down and either she quickly falls asleep or all of a sudden she snaps out of it and just talks nicely.
We wonder whether she is awake through these episodes just like those who have night terrors.
This routine of thirst, cough, phlegm, runny nose is how it unfolds each and every time.
Any ideas parents ?