What is the most common site of complications in rheumatic fever?

Rheumatic fever is a complication that can arise following a streptococcal throat infection and is characterized primarily by inflammation of the heart, joints, skin, and central nervous system. Among the potential cardiac complications, the mitral valve is recognized as the most commonly affected valve in rheumatic fever.

This predisposition can be attributed to the immunological response triggered by the initial infection. The antibodies produced in response to the Group A Streptococcus can mistakenly target the body's own tissues, including the heart valves. The mitral valve typically experiences damage due to this cross-reactivity, leading to conditions such as mitral stenosis or regurgitation, which can arise either acutely during the febrile illness or as chronic sequelae over time.

Additionally, while both the aortic and tricuspid valves can be involved, they are less commonly affected compared to the mitral valve in the context of rheumatic fever. The pulmonic valve is rarely involved in rheumatic heart disease. Thus, the predominant involvement of the mitral valve aligns with clinical observations and the underlying pathophysiology associated with rheumatic fever, confirming it as the site most frequently associated with complications.