Hematology and Oncology Book

Coagulopathy

Platelet Disorders

Rheumatology

  • Henoch-Schonlein Purpura

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Henoch-Schonlein PurpuraAka: Henoch Schonlein Purpura, Henoch-Schoenlein Purpura, Henoch Schoenlein Purpura, HSP

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  1. Epidemiology
    1. Children and young adults
      1. Peak Incidence at 5 year old
      2. Ages 2-11 years represent 75% of cases
      3. Milder case occur in children under age 2 years
    2. Occurs more often in boys (2:1)
    3. Incidence: 14 cases per 100,000
    4. Occurs most frequently in spring and fall
  2. Pathophysiology
    1. Idiopathic inflammatory IgA hypersensitivity
    2. Diffuse Vasculitis from immune complex deposition
    3. Upper Respiratory Infection precedes in 60-75% cases
  3. Associated conditions preceding HSP
    1. Infectious agents
      1. Group A Streptococcus (most common)
      2. Mycoplasma
      3. Epstein-Barr Virus
      4. Varicella Zoster Virus
      5. Parvovirus B19
      6. Campylobacter enteritis
    2. Vaccinations
      1. Typhoid
      2. Measles
      3. Cholera
      4. Yellow Fever
    3. Environmental exposures
      1. Allergens in drugs and foods
      2. Cold exposure
      3. Insect Bites
  4. Symptoms: Classic Triad
    1. Palpable Purpuric rash on lower extremities
    2. Abdominal Pain or renal involvement (Nephritis)
    3. Arthritis
  5. Signs: Rash (100% of cases)
    1. Timing
      1. Rash precedes other signs and symptoms of HSP
      2. First appears as erythematous Papules
      3. Purpuric rash follows
    2. Distribution
      1. Typically appears on lower extremities and buttocks
      2. Can involve extremities, face and trunk
      3. Gravity and pressure dependent
    3. Classic lesions
      1. Urticarial wheels
      2. Erythematous Macules
      3. Erythematous Papules
      4. Target lesions
      5. Petechiae
      6. Purpura
        1. Initially blanch on pressure; later they do not
        2. Purpura Color changes over time
          1. Initially red-purple
          2. Becomes rust-colored with brownish hue
          3. Fades as illness resolves
          4. Lesions may become hemorrhagic or necrotic
  6. Signs: Abdominal Pain (65% of cases)
    1. Colicky Abdominal Pain (may mimic Acute Abdomen)
    2. Stools may show occult or gross blood
    3. Vomiting, Hematemesis
  7. Signs: Joint Involvement (70% of cases)
    1. Transient arthritis with no permanent deformity
      1. Ankles and knees most commonly affected
      2. Elbows, hands and feet may also be affected
    2. Arthritis precedes rash in 25% of cases
  8. Signs: Renal Disease (25-50% of cases)
    1. General
      1. Most serious complication of HSP
      2. Develops within 3 months of rash
    2. Presentation
      1. Hematuria most common presenting sign
  9. Complications
    1. Myocardial Infarction
    2. Pulmonary hemorrhage
    3. Pleural Effusion
    4. Intussusception
    5. Gastrointestinal Bleeding
    6. Bowel infarction
    7. Renal Failure
    8. Hematuria
    9. Proteinuria
    10. Seizures
    11. Mononeuropathies
  10. Differential Diagnosis
    1. Hypersensitivity Vasculitis
      1. Elevated Renal Function tests (BUN, Creatinine)
      2. Global organ involvement
    2. Acute Abdomen
    3. Meningococcal Meningitis or septicemia
    4. Rheumatoid Arthritis
    5. Rheumatic Fever
    6. Idiopathic Thrombocytopenic Purpura
    7. Systemic Lupus Erythematosus
    8. Child Abuse
    9. Drug Reactions
    10. Bacterial endocarditis
    11. Rocky Mountain Spotted Fever
  11. Diagnostics
    1. Abdominal Ultrasound
      1. If GI symptoms present
    2. Skin Biopsy
      1. Leukocytoclastic Vasculitis
    3. Renal Biopsy
      1. Glomerular crescents
      2. Indistinguishable from IgA Nephropathy
  12. Labs
    1. Complete Blood Count (CBC)
      1. Leukocytosis with Eosinophilia
      2. Platelets may be elevated
        1. Low platelets suggest Thrombocytopenic Purpura
    2. Sedimentation rate (ESR) variably elevated
    3. Urinalysis
      1. Hematuria may be present
    4. Stool Guaiac
      1. Occult or gross blood may be present
    5. Renal Function tests (BUN, Creatinine)
      1. Elevation may suggest Hypersensitivity Vasculitis
  13. Management
    1. No specific treatments are available
    2. Bedrest
    3. Hydration
    4. NSAIDs for joint pain
    5. Systemic Corticosteroids for severe Abdominal Pain
  14. Course
    1. Lasts 4-6 weeks
    2. Recurrence in 50% of patients
  15. Prognosis
    1. Excellent in general
    2. Renal Disease develops in 5% (<1% develop ESRD)
    3. Predictors of serious nephropathy or ESRD
      1. Bloody stools
      2. Rash persistence
      3. Nephritis-Nephrotic Signs
        1. Progresses to ESRD within 10 years in 50% of cases
      4. Renal Biopsy with glomerular crescents
        1. Progresses to ESRD in 100% of cases
  16. References
    1. Kraft (1998) Am Fam Physician 58(2):405
    2. Saulsbury (2001) Curr Opin Rheumatol 13(1):35

Heat shock proteins (C0018850)

Definition (MSH)Proteins which are synthesized in eukaryotic organisms and bacteria in response to hyperthermia and other environmental stresses. They increase thermal tolerance and perform functions essential to cell survival under these conditions.
Definition (CSP)any of a group of proteins that are synthesized in response to hyperthermia, hypoxia, or other stresses and that are believed to enable cells to recover from these stresses, perhaps by enabling recovery of gene expression; occur in prokaryotes and eukaryotes, and at least some proteins are similar in vertebrates and invertebrates.
Definition (NCI)A family of highly-conserved proteins that are synthesized in response to hyperthermia (heat shock), hypoxia, or other stresses that appear to increase cellular thermal tolerance and enable cells to recover from stress. Some heat shock proteins may protect other proteins from denaturation, degradation or perform functions essential to cell survival under these conditions.
ConceptsAmino Acid, Peptide, or Protein (T116) , Biologically Active Substance (T123)
EnglishHeat Shock Protein, Heat shock proteins, HSP, Stress Proteins
CreditsDerived from the NIH UMLS (Unified Medical Language System)



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