- Kidneys, GU tract
- Peripheral nerves
- Medium-sized vessel vasculitis
- Hepatitis B, C, HIV, Hairy cell leukemia
- More commonly sub-acute over months
- Fever, sweats,, malaise, weight loss, muscle/joint pain
- Multiple systems: arthritis, skin findings, other GU organ involvement (e.g. testicular pain, renal infarct) from arterial insufficiency
- Abdominal pain--> blood per rectum
- Peripheral nerve pain and motor dysfunction
- Can sometimes also develop mono-neuritis multiplex--> weakness, numbness pain affecting specific PN
- Hypertension
- Skin w/ulcers
- Small, palpable purpura→ don't blanch when compress them, can coalesce
- Peripheral neuropathy related: decreased distal sensation, weakness, diminished reflexes
- Elevated ESR, biopsy of skin or affected organ, angiography
- If renal involvement, insufficiency related to ischemia (renal artery vasculitis) and not glomerulonephritis