II. Epidemiology

  1. Age of onset
    1. Type I Diabetes Mellitus: 22 (mean age of onset)
    2. Type II Diabetes Mellitus: 30 to 50 years
  2. Most common in women by 3 fold

III. Pathophysiology

  1. Unknown etiology
  2. Appears related to microvascular changes

IV. Associated Conditions: Diabetes Mellitus

  1. Necrobiosis patients with comorbid diabetes: 11-65%
  2. Prevalence of necrobiosis in Diabetes: 0.3 to 1.6%
  3. Necrobiosis predicts of future diabetes development

V. Symptoms

  1. Lesions are painless in most cases

VI. Signs

  1. Slowly growing oval atrophic Plaques
    1. May be several centimeters in size
    2. Initial
      1. Erythematous Plaque with raised irregular border
    3. Later
      1. Yellow brown waxy central atrophic area
  2. Distribution
    1. Classic (Diabetes): Bilateral shins, medial malleolus
    2. Other less-commonly involved locations
      1. Hands and Forearms
      2. Face and scalp
      3. Abdomen
  3. Telangiectases (subcutaneous vessels)
  4. Lesions may ulcerate with Trauma (risk of infection)
  5. Associated Neuropathy in 50% of patients
    1. Decreased pinprick and fine Touch Sensation

VII. Labs: Biopsy (often not needed)

  1. Necrobiosis of collagen
  2. Histiocytes and Lymphocytes surround collagen
  3. Inflammation around blood vessels

VIII. Differential Diagnosis

  1. Dermatopathology
    1. Granuloma Annulare
  2. Clinical
    1. Rheumatoid Nodules in Rheumatoid Arthritis
    2. Erythema Nodosum

IX. Management

  1. Corticosteroids
    1. Clobetasol Propionate under Occlusion for 6 weeks
    2. Intralesional Kenalog 10 mg/ml (dilute to 2.5 mg/ml)
    3. Oral Prednisone for 5 weeks
  2. Topical Psoralen with Ultraviolet A Exposure (PUVA)
  3. Inhibition of Platelet aggregation
    1. Pentoxifylline (Trental) 400 mg PO tid for 4-8 weeks
    2. Aspirin 325 mg PO qd for 3 to 7 months
    3. Dipyridamole (Persantine) 150-200 mg PO divided qid
  4. Skin Grafting or local excision
    1. Not recommended due to high recurrence rate
    2. Extensive skin involvement refractory to above
  5. Other treatment modalities
    1. Laser treatment for telangiectasias
    2. Benzoyl Peroxide for ulcerated lesions

X. Course

  1. Gradually resolves over 6-12 year period
  2. Residual atrophy persists after resolution

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