My son's tonsil's did the same thing.
He was not sick (no fever) but when he was not quite 4 his tonsils were so large they almost touched each other across the back of his throat.
He snored something awful when he slept - he had constant dark circles under his eyes because you don't sleep well when you snore that badly.
He had trouble breathing, eating and swallowing.
We tried to shrink them with the steroids - they shrunk to about half what they were but were still very large - and as soon as we finished the steroids the tonsils swelled right back up again.
The ENT said sometimes huge tonsils just run in familys.
(I remember I had mine out when I was in kindergarten and mine were so big I could almost chew on them. - My sister, the same thing.)
Honestly for my son they had become an obstruction.
So right after his 4th birthday we had his tonsils and adenoids removed.
His recovery was fast - his breathing was SO quiet now when he slept I kept checking on him to make sure he was breathing (we'd forgotten how quiet breathing was suppose to be) - he was fine.
No more dark circles under is eyes!
He could eat, drink, swallow and sleep!
He did so much better in pre-school since he wasn't cranky and tired all the time.
It was the best thing we ever did - we have no regrets!