If left untreated, what complications can strep throat cause?

Strep throat, caused by infection with the bacteria Streptococcus pyogenes, can lead to serious complications if not treated. One of the most significant complications is rheumatic fever, which can develop from an autoimmune response triggered by the infection. This inflammatory reaction can affect the heart, joints, skin, and central nervous system. Over time, rheumatic fever can cause long-term damage to the heart valves, leading to rheumatic heart disease.

Additionally, untreated strep throat can lead to kidney complications, particularly glomerulonephritis. This condition affects the kidney's filtering units and can result from an immune response to the streptococcal infection. Symptoms may include swelling, high blood pressure, and changes in urine output.

Understanding these associations emphasizes the importance of timely diagnosis and treatment of strep throat to prevent these severe complications. The other potential conditions mentioned in the other options do not directly arise from untreated strep throat in the same manner.