Vasculitis
Many thanks to Dr. Marcia Friedman for this fantastic overview on vasculitis, a fascinating group of diseases!
Plugging-in a mnemonic I learned in medical school:
Small vessel vasculitis involves “SKELN” - skin, kidney, ENT, lung, nerve
—Mengyu (rheumatology enthusiast)
A few notes on pathology explanation:
Rash in small vessel vasculitis is non-blanching because blood vessels are damaged
Pathology of livedo reticularis: zone of arterial cone (hypoperfusing) +zone of venous drainage
Glomerulonephritis in small vessel vasculitis is featured by active urine sediments (RBC, protein, casts) - things that should stay in the blood spill into urine
DAH (ie, capillaritis) is a medical emergency, as there is nothing to tamponade. BAL is features by “bloodier and bloodier” tubes
Mononeuritis multiplex is a misnomer - it’s not nerve inflammation per se; it’s involvement of vasa nervorum which supplies the nerve, and the nerve becomes ischemic.
GCA causes loss of vision (anterior ischemic optic neuropathy), as well double vision (oculomotor palsy). Scleritis (painful red eye) is small vessel involvement.
Vasculitis Mimics: