Chapter 17: Fever Evaluation & Management

Fever Evaluation & Management categorizes fevers based on pathophysiology, distinguishing between those responsive to antipyretics and those caused by heat stroke or drug toxicity, while also defining Fever of Unknown Origin (FUO) based on duration and diagnostic resistance. The text outlines a systematic diagnostic reasoning process, emphasizing the importance of collecting a focused history regarding fever onset, duration, measurement methods, and associated symptoms to identify localizing signs of infection in the respiratory, gastrointestinal, or genitourinary tracts. Significant attention is placed on age-specific considerations, noting that neonates and young infants often present with nonspecific signs like lethargy or poor feeding which may indicate serious bacterial infections like sepsis or meningitis, whereas older adults frequently exhibit a blunted febrile response with lower baseline body temperatures. The physical examination section highlights critical assessments, including checking for nuchal rigidity (Kernig and Brudzinski signs) to rule out meningitis, inspecting the skin for petechial rashes indicative of meningococcemia or vasculitis, and evaluating tympanic membranes for otitis media. The chapter also covers the relevance of travel history, animal exposure, and immunization status in identifying etiologies like malaria, cat-scratch disease, or vaccine-preventable illnesses. Diagnostic strategies are reviewed, ranging from basic laboratory studies like complete blood counts and urinalysis to invasive procedures such as lumbar punctures and blood cultures for detecting occult bacteremia or osteomyelitis. Finally, the summary concludes with a broad differential diagnosis framework, contrasting self-limiting viral upper respiratory infections against critical conditions such as Kawasaki disease, pelvic inflammatory disease, and deep tissue infections.