this is a huge bugbear of mine (being a nurse and therefore unsympathetic to nonsense).
Got a call from the school, can i please come and pick ds1 up because hes a bit pale and feels a bit sick.
So i aked if hed actually been sick and they said no but theyd like me to go pick him up 
When i was at school (80s) youd have to be bleeding out of your eyes before theyd call your parents! If id been at work it wouldve been tough!
Doesnt it just set the example that you can say you feel a bit whatever and then go home?
Suprise hes spemt 20mins in bed and now 'feels better' 