How long can you leave strep throat untreated before its could turn serious. i've had white spots in throat for four days now. no fever no pain?

White spots: The white spots in your throat arent necessarily due to strep. The exsudate may in fact, be due to a virus. You should see your doctor for a culture for a definitive diagnosis. You can go about a week before a strep infection can start giving you problems.

White spots: In the throat does not necessarily mean strep throat.You don't have any other signs and symptoms. More than likely food particles or tonsilloliths which are benign.Consult your physician if you start spiking a fever, swollen glands, fatigue, achy etc.

1 week: I think that the general consensus is that you have a week to treat in order to prevent serious complications such as rheumatic fever, heart disease, kidney disease, etc.

Define "serious": The major issue I worry about is the 1/200 that will trigger antibodies that attack the heart/brain/kidneys, a process lumped into the Rheumatic fever label. Data suggests 10 days from the first fever as the window of opportunity to treat & stop RF. It is probably only 5-7 days to stop the kidney failure. Some strep cases actually improve without meds, but go on to develop the complications later.