Concept of Vasculitis: Vasculitis of small vessels (arterioles, venules, capillaries), muscular
arteries, and elastic arteries. All of these vasculitis present with different signs and symptoms
(ie like coagulation disorders vs. platelet disorders).
Small vessel vasculitis – 99% of the time it is due to a type III HPY, meaning it is involves
immune complex deposition, that will deposit in the small vessel, activate complement and
attract neutrophils (C5a), and will get fibrinoid necrosis and damage to the small vessel and
PALPABLE PURPURA; (remember the old person with purpura on the back of the hand – that
was not palpable and was due to hemorrhage into the skin, there was no inflammatory
problem – it just ruptured into the skin) but if it was palpable, it would be considered a SMALL
VESSEL vasculitis not a platelet problem.
Leukocytoclastic vasculitis (hypersensitivity vasculitis);
nuclear dust = fibrinoid necrosis and immune complex dz’s; and
Henoch-Schonlein purpura. So, SMALL VESSEL vasculitis = PALPABLE purpura (always told in
the stem of the question).
Muscular artery vasculitis – Polyarteritis Nodosa and Wegener granulomatosis. These will get
THROMBOSIS of the vessel, not palpable purpura. Will have INFARCTION. Example:
Kawasaki’s Dz in children “crims” coronary artery vasculitis ,rash,infarction,mi, swelling
– get coronary artery vasculitis – MCC MI in children = Kawasaki’s dz – b/c part of the
syndrome, in addition to mucocutaneous inflammation, desquamation of skin, and
lymphadenopathy, there is a coronary artery vasculitis – thrombosis occurs and little child will
have an infarction. So, infarction is what you see with a muscular artery vasculitis. Examples:
Polyarteritis Nodosa, Wegener granulomatosis, Kawasaki’s dz in kids.
Elastic artery vasculitis – When you knock off an elastic artery, then you deal with arch vessels,
and they will get pulseless dz=Takayasu’s arteritis – the vasculitis will block off the lumen of one
of the arch vessels, leading to STROKES and can knock off the internal carotid. Example:
Takayasu’s – young, far eastern lady with absent pulse.
So, palpable purpura = small vessel vasculitis
Infarction = muscular vasculitis
Involves pulse/stroke = elastic artery vasculitis
Temporal Arteritis – unilateral headache, aches and pains all over body, loss of vision of same
side of headache, hurts when pt chews in temporal area. This is a granulomatous (have
multinucleated giant cell) vasculitis of the temporal artery, a type of giant cell arteritides. It can
involve other portions of the artery including the ophthalmic branch and produce blindness.
That’s why the sedimentation rate is the ONLY screen discreet for temporal arteritis. Why? Not
that it is specific, but b/c this is an arteritis, (an inflammation) the sed rate should be elevated.
If the sed rate is NOT elevated, it could be a transient ischemic attack. This is good screen b/c it takes time to take a biopsy and look at it, and the pt could go blind. So, you must put the pt on
corticosteroids immediately (right there and then) just based on hx alone. The pt will be on
corticosteroids for one year. It’s associated with polymyalgia rheumatica – muscle aches and