Differential Diagnosis for LCV Vasculitis

The following list presents a differential diagnosis for Leukocytoclastic Vasculitis (LCV), categorized from most common to least common as the primary cause, along with key diagnostic criteria and justifications.

• Single Most Likely Diagnosis

  • Henoch-Schönlein Purpura (HSP)
    • Key diagnostic criteria:
      • Palpable purpura
      • Abdominal pain
      • Arthritis
      • Renal involvement
    • Justification: HSP is the most common form of systemic vasculitis and a leading cause of LCV, especially in children and young adults.

• Other Likely Diagnoses

  • Essential Mixed Cryoglobulinemia
    • Key diagnostic criteria:
      • Cryoglobulins in serum
      • Skin, joint, and kidney involvement
      • Hepatitis C infection often associated
    • Justification: This condition is known to cause LCV and is associated with various infections, including hepatitis C, and autoimmune diseases.
  • ANCA-Associated Vasculitis (e.g., Granulomatosis with Polyangiitis, Microscopic Polyangiitis, Eosinophilic Granulomatosis with Polyangiitis)
    • Key diagnostic criteria:
      • Presence of ANCA antibodies
      • Respiratory and renal involvement
      • Granulomatous inflammation on biopsy
    • Justification: These conditions can present with LCV and are characterized by the presence of ANCA antibodies, affecting small to medium-sized vessels.
  • Infection-Associated Vasculitis
    • Key diagnostic criteria:
      • Recent or ongoing infection
      • Positive blood cultures or serology
      • Response to antimicrobial therapy
    • Justification: Various infections can trigger LCV, making it essential to investigate recent infections or exposures.

• Do Not Miss Diagnoses

  • Malignancy-Associated Vasculitis
    • Key diagnostic criteria:
      • Underlying malignancy
      • Atypical or unexplained vasculitis presentation
      • Paraneoplastic phenomena
    • Justification: Although rare, vasculitis can be a paraneoplastic syndrome, and missing an underlying malignancy could be fatal.
  • Drug-Induced Vasculitis
    • Key diagnostic criteria:
      • Recent introduction of a new medication
      • Temporal relationship between drug use and vasculitis onset
      • Improvement upon drug withdrawal
    • Justification: Certain drugs can induce LCV, and failing to recognize and withdraw the offending agent could lead to prolonged illness.

• Rare Diagnoses

  • Relapsing Polychondritis
    • Key diagnostic criteria:
      • Recurrent cartilaginous inflammation
      • Involvement of ears, nose, trachea, and joints
      • Ocular and audiovestibular manifestations
    • Justification: Although rare, relapsing polychondritis can present with LCV among its diverse manifestations.
  • Behçet's Disease
    • Key diagnostic criteria:
      • Recurrent oral ulcers
      • Genital ulcers
      • Ocular involvement
    • Justification: This multisystem disorder can include LCV among its manifestations, particularly in the context of systemic inflammation and vasculitis.