Hi,
Has he taken any antibiotics in last few days?
I think he is having an oral thrush or mouth candidiasis.t is fungal infection that can occur when you have a weak immune system.Nystatin Drops or rinses are used but as these are not available over the counter .Also your liver should be functioning normally when these drugs are taken (as they affect liver) so its better to see your physician .
Regards,
Dr.Naeem
Never prescribed it so have no idea.But some people reported recovery after its use.Its upto you if you want to give a try probably there is no harm as its plant in origin.
Doctor (MD)
Medical Doctor,Ireland.