What is a common complication associated with untreated streptococcal pharyngitis?

Rheumatic fever is a common complication associated with untreated streptococcal pharyngitis, particularly in children. This condition arises as an autoimmune response to the infection caused by Group A Streptococcus bacteria. When the throat infection is not properly treated, the immune system may mistakenly attack the body’s own tissues, particularly affecting the heart, joints, skin, and central nervous system. This can lead to serious complications such as rheumatic heart disease, which can cause permanent damage to the heart valves.

While scarlet fever can occur as a result of streptococcal pharyngitis due to the presence of a specific toxin, it is often viewed as a manifestation rather than a direct complication. The other options—bronchitis and pneumonia—are generally not subsequent issues stemming from untreated streptococcal pharyngitis but rather relate to different infectious processes or complications altogether. Therefore, rheumatic fever stands out as a critical and severe consequence of untreated streptococcal pharyngitis, necessitating early identification and treatment of the infection to prevent it.