Question: Can you identify this condition?

A 62-year-old Mediterranean man presented with a 4-day history of chills, shivering, fever (40°C), general fatigue, nonpruritic maculopapular rash, and muscle weakness. He developed the chills 6 days after working on a farm near the mountains surrounding Madrid, Spain, then noticed an insect bite on his left elbow.

The maculopapular rash first appeared on his forearms and extended to his trunk; it spared his palms and soles. Examination also revealed a single ulcerative lesion on his left elbow, approximately 15 mm in diameter, covered by a dry, black eschar. He had lymph node enlargement in his left axilla. The rest of the physical examination did not reveal hepatosplenomegaly or other abnormalities.

Laboratory analyses showed the following values: hemoglobin, 14.9 g/dL; leukocyte count, 4300/L with predominant neutrophils; mild thrombocytopenia (platelet count, 132 × 103/L); aspartate aminotransferase, 73 IU/L; alanine aminotransferase, 47 IU/L; mild hyponatremia (sodium, 131 mg/dL), C-reactive protein, 60 mg/dL. Chest radiographs were unremarkable.

The most likely diagnosis is

1. Trypanosomiasis

2. Mediterranean spotted fever

3. Lyme disease

4. Q fever

5. Dengue

Answer on page 807

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