quizlet a 10-year-old boy is seen in a rural arizona clinic because of prostration, fever of 40°c (104°f), and severe headache. examination is negative for rash, stiff neck, joint tenderness, and chest and abdominal abnormalities. however, several tender, enlarged lymph nodes are palpated in the left axilla, which is very edematous. he has a history of being bitten by fleas. the most likely diagnosis is: