Bornholm's disease, according to the books, usually occurs with fever and a cough, is generally accompanied by severe chest pain attacks lasting one to three days, and almost always resolves in a month.
But there are always exceptions to every rule, and your son may be one. The virus that causes it, Coxsackie B, lives in the intestines and passes to new victims through poor handwashing or contaminated food.
The virus attacks the muscles between the ribs, killing the cells and causing inflammation.
Attacks are described as remarkably painful and sudden but, on the bright side, even the worst cases seem to go away with time.
One brief aside regarding psychosomatic illness: it's common and often presents with unusual symptoms that defy diagnosis, and causes very real pain to the people suffering from it.
If doctors don't consider it, they'll never get it diagnosed correctly.
So please don't be put off if your doctor asks about it, or about other diagnoses such as depression - they're trying to do the right thing.
Best wishes for your son's complete recovery.
Gary Payinda MD is an emergency medicine consultant in Whangarei.
If you have a science or health topic question you'd like addressed, email drpayinda@gmail.com
(This column provides general information and is not a substitute for the advice of your doctor.)