Chapter 61: Common Hematological and Immunological Complaints

Bruising, or ecchymosis, represents blood extravasation into interstitial tissue and follows a predictable color progression as macrophages break down erythrocytes and release hemosiderin and hematoidin. While trauma is the most common cause, spontaneous bruising warrants investigation for thrombocytopenia, hematological malignancy, chronic corticosteroid use that compromises vascular integrity, or anticoagulant therapy; clinicians managing warfarin therapy typically maintain international normalized ratio values between 2.0 and 3.0 to balance efficacy against bleeding risk. Fatigue presents diagnostically challenging because it encompasses multiple etiologies requiring careful phenomenological characterization—acute fatigue typically accompanies infection, while chronic fatigue that worsens throughout the day but improves with rest suggests medical disease such as anemia, whereas cancer-related fatigue is described as paralyzing, sudden in onset, and unresponsive to sleep or rest. Fever, defined as temperature elevation above an individual's baseline, manifests as either acute high-grade fever suggesting infection or drug reaction, or chronic low-grade fever that may herald hematological malignancy; fever of unknown origin requires sustained elevation above 101.3°F documented on at least three separate occasions over three weeks without identified etiology after standard diagnostic workup. Older adults present special consideration because age-related immune decline may blunt the febrile response, instead producing atypical presentations such as confusion or delirium. Lymphadenopathy describes lymph node enlargement or abnormality and classifies as regional when localized proximal to infection sites, systemic when involving three or more dispersed sites, or lymphadenitis when inflammation is the underlying mechanism; age significantly influences diagnostic interpretation, as slow-growing cervical lymphadenopathy in patients over seventy carries high suspicion for lymphoma, while the same finding in younger patients without tobacco exposure suggests benign etiology. Tender nodes typically indicate acute infection, whereas malignancy and chronic conditions like HIV produce nontender nodes; HIV-associated lymphadenopathy may present as reactive hyperplasia in early disease or progress to involve opportunistic infections and human papillomavirus-related neoplasms in advanced stages.