Hypersensitivity angiitis

Question 1

What is it?

Answer 1

acute

necrotizing

inflammatory disease

of the smallest vessels (arterioles, venules, capillaries)

Question 2

Where is it?

Answer 2

Most commonly in the skin and limited to the skin

Question 3

What is cutaneous hypersensitivity angiitis called?

Answer 3

Leukocytoclastic vasculitis

Question 4

Leukocytoclastic vasculitis causes

Answer 4

10% due to drugs (quinolones, PCN, sulfas)
infections
tumors

Question 5

What is hypersensitivity angiitis involving internal organs?

Answer 5

Microscopic polyangiitis

Question 6

Organs involved in microscopic polyangiitis

Answer 6

kidneys
musculoskeletal
lungs
gut
skin
ear, nose, and throat

Question 7

Pathogenesis

Answer 7

immune-complex deposition and complement activation 7-10 days following antigen exposure

Question 8

Pathology

Answer 8

1. infiltration of blood vessels by neutrophils
2. leukocytoclasia (breakdown) disperses nuclear dust
3. fibrinoid change, thrombosis rupture, hemorrhage
4. lymphocytic infiltration

**Lesions are usually all in the same phase

Question 9

Signs and symptoms

Answer 9

Many (pts are very sick)

Palpable purpura!! (esp in lower legs)

Question 10

diagnosis

Answer 10

biopsy (usually of skin)

Question 11

Treatment of Leukocytoclastic angiitis

Answer 11

Stop causative agent (i.e. drug, infection, tumor)

Question 12

Treatment of microscopic polyangiitis

Answer 12

immunosuppressive therapy

cyclophosphamide + steroid