Purpura

Sep 16, 2019 admin DA LIỄU 0

Purpura

Aka: Purpura, Purpuric rash, Petechiae, Ecchymosis, Ecchymoses

II. Definitions

  1. General: Non-blanching cutaneous Hemorrhages
  2. Petechiae: Pinpoint Hemorrhages <2 mm in diameter
  3. Purpura: 2 to 10 mm in diameter
  4. Ecchymosis: >10 mm in diameter

III. Signs: Purpura

  1. Visible non-blanching Hemorrhages
    1. Compare with Contusions which are Traumatic non-blanching Hemorrhages
    2. Contrast with Vascular Skin Reaction which does blanch
  2. Occurs in the skin or mucus membranes
  3. Size: 2-10 mm in diameter (see definitions above)
  4. Characteristics
    1. Palpable Purpura suggests Vasculitis
  5. Distribution
    1. Petechiae on the head or neck
      1. Violent coughing (e.g. Pertussis), Vomiting or strangulation
    2. Purpura on Lower extremities (gravity dependent)
      1. Henoch-Schonlein Purpura
    3. Purpura on palms and soles
      1. Rickettsial infection

IV. Signs: Associated Conditions

  1. See Purpura Causes
  2. See Thrombocytopenia
  3. Fever and ill appearing or signs of toxicity
    1. Meningococcemia or Meningitis
    2. Pneumococcal Pneumonia
    3. Sepsis with Disseminated Intravascular Coagulation (DIC)
    4. Rocky Mountain Spotted Fever
  4. Fever without signs of toxicity
    1. Mononucleosis (EBV)
    2. Adenovirus
    3. Pertussis
    4. Streptococcal Pharyngitis
      1. Also most common cause of Henoch-Schonlein Purpura
  5. Preceding viral illness
    1. Idiopathic Thrombocytopenic Purpura
  6. Hepatosplenomegaly and Lymphadenopathy
    1. Malignancy (e.g. Leukemia)
    2. Mononucleosis (EBV)
  7. Hypertension
    1. Chronic Renal Failure
    2. Renal Vasculitis
    3. Hemolytic Uremic Syndrome
  8. Hemarthrosis
    1. Hemophilia
    2. Von Willebrand Disease
  9. Arthralgias
    1. Henoch-Schonlein Purpura
    2. Rheumatologic causes (esp with eye symptoms)
  10. Skeletal abnormalities
    1. Thrombocytopenia-absent radii (TAR syndrome)
    2. Fanconi’s Anemia (Short Stature)
  11. Skin hyperelasticity and joint hypermobility
    1. Ehlers-Danlos Syndrome
  12. Telangiectases
    1. Hereditary Hemorrhagic Telangiectasia
    2. Liver disease

V. Labs: General

  1. Initial Tests
    1. Complete Blood Count with Platelet Count
    2. Peripheral Smear
    3. Coagulation tests (INR, PTT)
    4. Urinalysis with microscopic exam
  2. Tests to consider
    1. Comprehensive Metabolic Panel
    2. Blood Cultures (fever, ill appearance and Petechiae/Purpura)
    3. Streptococcal Test
    4. Monospot (EBV titer in age <5 years old, Monospot inaccurate in that group)

VI. Labs: Complete Blood Count and Peripheral Smear

  1. Schistocytes
    1. Hemolytic-Uremic Syndrome
    2. Thrombotic Thrombocytopenic Purpura
    3. Disseminated Intravascular Coagulopathy
  2. Atypical Lymphocytosis
    1. Infectious Mononucleosis
    2. Cytomegalovirus
    3. Leukemia blast cells with similar appearance
  3. Reticulocyte Count increased
    1. Hemolytic Anemia

VII. Labs: Platelet Count and Indices

  1. Anemia and Thrombocytopenia
    1. Leukemia
    2. Systemic Lupus Erythematosus
    3. Aplastic Anemia
  2. Thrombocytopenia with otherwise normal CBC
    1. Idiopathic Thrombocytopenic Purpura
  3. Altered platelet size
    1. See Mean Platelet Volume (MPV)

VIII. Labs: Urinalysis with Hematuria or Proteinuria

  1. Henoch-Schonlein Purpura
  2. Systemic Lupus Erythematosus
  3. Hemolytic-Uremic Syndrome

IX. Causes

  1. See Purpura Causes

X. Approach: Children (older protocol)

  1. Step 1 (non-bleeding cause)
    1. If unable to identify cause, go to step 2 below
    2. Identify potential cause based on history and exam
      1. See Purpura Causes
      2. See Signs above
  2. Step 2 (bleeding cause)
    1. Obtain Bleeding Disorder lab-work
      1. Complete Blood Count (CBC) with Platelet Count
      2. Peripheral Blood Smear
      3. ProTime
      4. Activated Partial Thromboplastin Time (aPTT)
    2. Evaluate Platelet Count
      1. Platelet Count low: Go to Step 3a below
      2. Platelet Count normal: Go to Step 3b below
  3. Step 3a (Low Platelet Count)
    1. See Thrombocytopenia
    2. Prothrombin Time and aPTT prolonged
      1. Sepsis
      2. Disseminated Intravascular Coagulopathy
    3. Prothrombin Time and aPTT not prolonged
      1. Idiopathic Thrombocytopenic Purpura
      2. Hemolytic-Uremic Syndrome
      3. Thrombotic Thrombocytopenic Purpura
      4. Systemic Lupus Erythematosus
      5. Bone Marrow aplasia
      6. Platelet Sequestration
  4. Step 3b (Normal Platelet Count)
    1. Prothrombin Time and aPTT prolonged
      1. Coagulation Factor deficiency
      2. Von Willebrand’s Disease
      3. Circulating Anticoagulant
      4. Liver disease
    2. Prothrombin Time and aPTT not prolonged
      1. Go to Step 4 below
  5. Step 4 (Bleeding Time)
    1. Obtain Bleeding Time
    2. Bleeding Time prolonged
      1. See Platelet Dysfunction
      2. Von Willebrand’s Disease
    3. Bleeding Time normal
      1. Child Abuse (Nonaccidental Trauma)
      2. Von Willebrand’s Disease
      3. Vascular Purpura

XI. Disposition

  1. See Thrombocytopenia for hospitalization indications related to Low Platelets
  2. Admit or observe febrile or ill appearing patients with Petechiae or Purpura if no clear cause
  3. Well-appearing, afebrile infants with isolated, localized Petechiae and normal history exam are unlikely to have serious illness
    1. Lee (2012) Pediatric Emerg Care 28(6): 503-5 +PMID: 22653463 [PubMed]

XII. Precautions: Patients with bleeding tendency

  1. See Thrombocytopenia for activity and procedure limitations based on Platelet Count
  2. Caution with fever or ill appearing patients
    1. Consider Meningococcus, Pneumococcus, DIC, Rocky Mountain Spotted Fever
    2. Consider HSP, TTP, HUS
  3. Caution with strenuous activity or Contact Sport
  4. Caution with Intramuscular Injections
  5. Avoid Aspirin and NSAIDs

XIII. References

  1. Behar, Spangler, Swadron in Herbert (2016) EM:Rap 16(3): 14-6
  2. Baselga (1997) J Am Acad Dermatol 37:673-705 [PubMed]
  3. Leung (2001) Am Fam Physician 64(3): 419-28 [PubMed]
  4. Stevens (1995) Am Fam Physician 52(5):1355-62 [PubMed]

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