Which of the following is not a complication of untreated group A streptococcal pharyngitis?

Untreated group A streptococcal pharyngitis can lead to a variety of complications, but hemolytic anemia is not one of them.

Complications from untreated strep throat primarily arise from the body's immune response to the infection. Glomerulonephritis can develop as a post-infectious complication due to immune complexes that form after the initial infection. Rheumatic heart disease is associated with the systemic inflammation and autoimmune response triggered by the streptococcal infection, leading to damage to the heart valves. Scarlet fever is a rash caused by specific strains of the bacteria that produce toxins, typically occurring alongside the throat infection.

Conversely, hemolytic anemia is not directly linked to group A streptococcal infections or their sequelae. It generally arises from various conditions that cause the destruction of red blood cells rather than as a complication stemming from strep throat.