When I was a kid, a couple of hundred years ago, it was a common childhood malady. I don’t know if remains so, but in any case, here is a reading on tonsillitis along with its attendant vocabulary-building and comprehension worksheet if you can use them.
If you find typos in these documents, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.