Small vessel leukocytoclastic vasculitis

Small vessel leukocytoclastic vasculitis
Diagnosis in short
Leukocytoclastic vasculitis. H&E stain.
Synonyms	leukocytoclastic vasculitis, hypersensitivity vasculitis
LM	small vessels intramural inflammatory cells (neutrophils), vessel damage (fibrin deposition)
LM DDx	dermatitides with perivascular inflammation
Stains	PAS -ve
Site	blood vessels - see vasculitides
Signs	palpable purpura
Prevalence	uncommon
Prognosis	dependent on underlying cause
Clin. DDx	see etiology section
Treatment	remove underlying cause; colchicine and/or dapsone; immunosuppression

Small vessel leukocytoclastic vasculitis, also leukocytoclastic vasculitis (abbreviated LCV) and hypersensitivity vasculitis, is an inflammatory process of the small blood vessel.

General

• Most common cutaneous vasculitis.

Clinical:

• Palpable purpura, usu. lower extremity.

Treatment - dependent on cause - may include:

• Remove underlying cause if it can be determined.
• Colchicine and/or dapsone.
• Immunosuppression.

Etiology

Has a very broad DDx:

1. Infectious:
   • Bacterial.
   • Viral.
   • Fungal.
2. Vasculitic disorders:
   • ANCA mediated vasculitides:
     • Granulomatosis with polyangiitis (Wegener granulomatosis).
     • Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome).
   • Henoch–Schönlein purpura.
   • Urticarial vasculitis.
3. Other:
   • Connective tissue disease, e.g. mixed connective tissue disease, SLE, rheumatoid arthritis.
   • Cryoglobulinemia - may be due to multiple myeloma, hepatitis C; have intravascular thrombi.
   • Paraneoplastic.
   • Drugs.

Gross

• Palpable purpura - raised lesions that can appreciated with touch, red/purple in colour.

Microscopic

Features:

• Small upper dermis vessels with:
  1. Neutrophils.
     • Fragmentation of neutrophils (leukocytoclasia).
  2. Vessel damage: fibrin deposition (bright pink acellular stuff) or "nuclear dust" (punctate hyperchromatic material).

DDx:

• Dermatitides with perivascular inflammation.

Image

Case

• 

  LCV - very low mag. (WC)

• 

  LCV - low mag. (WC)

• 

  LCV - intermed. mag. (WC)

• 

  LCV - high mag. (WC)

• 

  LCV - very high mag. (WC)

www

• LCA (ancavasculitis.com).
• LCA of the GI tract - several images (upmc.edu).

Stains

• PAS - look for fungus.

Sign out

Skin, Left Outer Thigh, Punch Biopsy:
     - Hypersensitivity vasculitis (leukocytoclastic vasculitis).

Alternate

Skin, Right Leg, Punch Biopsy:
     - Leukocytoclastic vasculitis. 

Micro

The sections show red blood cells extravasation and nuclear dust. Scattered neutrophils are within the wall of small blood vessels.

See also

• Vasculitides.
• Inflammatory skin disorders.