MEDizzy - A 7-year-old boy presents with the acute onset of fever,

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Cardiovascular System

A 7-year-old boy presents with the acute onset of fever, pain in several joints, and a skin rash. Physical examination finds an enlarged heart, several subcutaneous nodules, and a skin rash on his back with a raised, erythematous margin. Laboratory tests find an elevated erythrocyte sedimentation rate and an elevated antistreptolysin O titers. Which one of the following is most likely to be present in the heart of this child?

ExplanationAnitschkow cells are modified tissue monocytes that are found in cardiac lesions of acute rheumatic fever (RF). They are located around areas of fibrinoid necrosis. This entire area is called an Aschoff body. The nuclei of the Anitschkow cells are long, slender, wavy ribbons that resemble a caterpillar (hence the name “caterpillar cells”). Occasional multinucleated giant cells (Aschoff cells) may be seen. The Aschoff body, which is pathognomonic for acute rheumatic fever, may be found in any of the three layers of the heart (pancarditis). RF is a systemic autoimmune disease that usually develops 10 days to 6 weeks after a pharyngeal infection with group A β-hemolytic streptococci. This autoimmune disorder results from cross-reactions between cardiac antigens and antibodies evoked by one of the many streptococcal antigens, for example, streptococcal M protein. There are no streptococci within any portion of the heart. Rheumatic fever produces both acute and chronic manifestations. The major clinical findings of acute RF include migratory polyarthritis of large joints, carditis, erythema marginatum of skin (although skin involvement is not very common), subcutaneous nodules, and Sydenham chorea. In contrast, chronic RF mainly produces damage to cardiac valves. The mitral valve is most commonly involved, followed by the aortic valve. The stenotic valve has the appearance of a “fish mouth” or “buttonhole.” An additional finding in chronic RF is a rough portion of the endocardium of the left atrium, called a MacCallum patch.