Constitutional Symptoms and Their Differential Diagnosis

Constitutional Symptoms and Their Differential Diagnosis

Constitutional Symptoms and Their Differential Diagnosis

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Constitutional Symptoms: Overview - Body's Red Flags

  • Definition: Non-specific systemic indicators: fever, weight loss, fatigue, night sweats, anorexia. Signal underlying disease.
  • General Approach:
    • History: Detail B symptoms (lymphoma).
    • Exam: Thorough physical.
    • Labs: CBC, ESR/CRP, LFT, RFT, TSH, urinalysis.

⭐ The presence of B symptoms (fever, night sweats, weight loss) in lymphoma significantly impacts staging and prognosis.

Fever: Investigation & Differentials - Heat of Battle

  • Definition: Oral temp >37.8°C (100.0°F), Core temp >38.3°C (101.0°F).
  • Fever Patterns: Sustained, Intermittent, Remittent, Hectic, Pel-Ebstein. Offer clues but have limited specific diagnostic utility. 📌 Mnemonic: SIR HP (Sustained, Intermittent, Remittent, Hectic, Pel-Ebstein). Fever Patterns: Sustained, Intermittent, Remittent, Hectic
  • Differential Diagnosis (DDx): Key categories:
    • Infections: TB, malaria, typhoid, UTI, pneumonia.
    • Malignancies: Lymphoma, leukemia, RCC, HCC.
    • Autoimmune/Inflammatory: SLE, RA, vasculitis, Still's disease.
    • Drug fever.
    • Miscellaneous: PE, DVT, gout, IBD, sarcoidosis.
  • Fever of Unknown Origin (FUO): Petersdorf & Beeson criteria: Fever >38.3°C (on several occasions), duration >3 weeks, no diagnosis after 1 week of inpatient investigation or 3 outpatient visits.

⭐ Pel-Ebstein fever, a cyclical fever pattern, is classically associated with Hodgkin's lymphoma.

FUO Diagnostic Approach (Indian Context)

Weight Loss: Unintentional Shedding - The Great Shrink

  • Significant: >5% body weight loss in 6-12 months or >4.5 kg.
  • Causes:
    • Malignancy (GI, lung, hematologic)
    • Chronic infections (TB, HIV, fungal)
    • Endocrine (hyperthyroidism, uncontrolled DM, adrenal insufficiency)
    • GI disorders (malabsorption, IBD, PUD)
    • Psychiatric (depression, anorexia nervosa)
    • Severe organ dysfunction (CHF, CKD, COPD)
    • Medications, Substance abuse
  • Initial Evaluation: History (diet, meds, psych), Physical Exam (seek red flags: lymphadenopathy, organomegaly, masses).

⭐ Occult malignancy is a leading cause of unexplained involuntary weight loss in the elderly, particularly GI and lung cancers.

Fatigue & Malaise: Chronic Drain - Energy Vampires

  • Fatigue: Subjective lack of physical/mental energy.
  • Malaise: General feeling of discomfort or illness.
  • Differential Diagnosis (Energy Vampires):
    • Infections: Chronic (TB, HIV, EBV, CMV, endocarditis)
    • Endocrine: Hypothyroidism, adrenal insufficiency, DM, hypogonadism
    • Hematologic: Anemia
    • Malignancy
    • Psychiatric: Depression, anxiety, somatization
    • Autoimmune: SLE, RA
    • Neuromuscular: MS, myasthenia gravis
    • Sleep disorders: OSA
    • Medications: Beta-blockers, sedatives
    • Chronic Organ Failure: Cardiac, renal, hepatic
    • Chronic Fatigue Syndrome (ME/CFS)
  • Red Flags: New/progressive fatigue, unexplained weight loss, persistent fever, lymphadenopathy, focal neurological signs.

⭐ Fatigue is a common presenting symptom of hypothyroidism and often improves significantly with thyroid hormone replacement.

Night Sweats & Anorexia: Damp & Diminished - Ominous Duo

  • Night Sweats: Drenching sweats, requiring change of bedclothes, not solely due to warm environment.
    • Key Causes: Infections (TB - classic, HIV, endocarditis), Malignancies (lymphoma - B symptom, leukemia), Endocrine (hyperthyroidism, pheochromocytoma), Medications (antidepressants, antipyretics), Autoimmune.
  • Anorexia: Loss of appetite.
    • Key Causes: Often overlaps weight loss causes (malignancy, chronic infections, GI disorders, depression, uremia). Differentiate from sitophobia (fear of eating due postprandial pain).

⭐ Drenching night sweats, especially when accompanied by fever and weight loss, are a strong indicator for investigating tuberculosis or lymphoma in the Indian context.

High‑Yield Points - ⚡ Biggest Takeaways

  • Fever of Unknown Origin (FUO): >3 weeks, >38.3°C, undiagnosed after 1 week inpatient workup.
  • Significant weight loss: >5% in 6-12 months; suspect malignancy, TB, hyperthyroidism.
  • Fatigue: Differentiate from weakness; consider anemia, hypothyroidism, chronic infections, depression.
  • Night sweats: Often with FUO; classic for TB, lymphoma, menopause.
  • Pallor: Suggests anemia; investigate nutritional deficiencies, chronic disease, blood loss.
  • Lymphadenopathy: Localized vs. generalized; consider infections, malignancy (lymphoma), autoimmune diseases.

Practice Questions: Constitutional Symptoms and Their Differential Diagnosis

Test your understanding with these related questions

An elderly woman presented with confusion, thirst, and abdominal pain symptoms. On examination, she had pallor and thoracic spine tenderness. X-ray spine showed osteolytic lesions. Her lab investigations showed the following findings. What is the most likely diagnosis? - Hb - 6.9 g/dl

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Flashcards: Constitutional Symptoms and Their Differential Diagnosis

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What is the earliest hematological response to iron therapy in iron-deficiency anemia?_____

TAP TO REVEAL ANSWER

What is the earliest hematological response to iron therapy in iron-deficiency anemia?_____

Bone marrow erythroid hyperplasia

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