Severs disease

My son (10) has just been diagnosed with severs disease. He is a keen and good cross country runner coming 5th in the state championships last year. So far he only has it in one heel. I’ve been reading aritcles on the net and it doesn’t sound promising. Is this the end of his running? What are the odds for recovery. What age do they usually grow out of it. I’ve been told 15 and I’ve been told 18? Who do I see for treatment? Should he be X-rayed. Should he take anti-inflamatories?

Would love to hear of some good news stories to give us hope.