Strep unchecked can progress to Rheumatic fever which can cause valvular damage.
No need to let Strep go untreated.
Well that's not necessarily true: Many people are colonized ( meaning they have the organism present chronically w/out actual infection) because the overuse of antibiotics. So the strep cultures and rapid tests will be positive in a portion of the population- and it has no clinical significance. Strep infection itself does not cause valvular heart disease- Rheumatic Fever, which rarely can be the consequence of strep infection, can cause the valvular disease.
The overwhelming majority of Strep throat infections are self-limiting and resolve within a few days.
I personally would not take antibiotics, or swab for strep, a simple case of sore throat.
The risks associated with antibiotics ( development of drug resistant organisms, the risk of gastrointestinal problems. and the risk of serious allergic reaction) far outweigh the benefits.
The underlying problem is that patients demand antibiotics and most of us cave to that demand since its much easier to give in, then to argue.