This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S., Subject name: Pediatrics
A 2 year old child with a known history of rheumatic heart disease presents with a 3 weeks history of fever with palpitations. Most likely cause is: 
Select and explain. 
A. Kawasaki's disease, B. Collagen vascular disease, C. Staphylococcal endocarditis, D. None of these
C: Staphylococcal endocarditis
Answer: C: Staphylococcal endocarditis 
Explanation: Ans. C. Staphylococcal endocarditisHistory of prolonged fever in a child with a previous history of heart disease should always raise suspicion of infective endocarditis. Since Staphylococcus is the most important cause, the best answer here should be Staphylococcal endocarditis