Vasculitis

p-ANCA immunofluorescence

Today we discussed the diagnosis and management of vasculitis, specifically ANCA-associated vasculitis. These diseases are rare, complex, multisystemic, and present many challenges to everyone involved (including those trying to blog about it). Good thing we had an expert!


When to suspect vasculitis?

1) Multiorgan involvement otherwise unexplained

2) Systemic symptoms (constitutional, etc. ) otherwise unexplained

3) Organ ischemia or infarction (bowel, renal, myocardial, etc)

4) Common condition in uncommon age group (MI, pulmonary edema, etc.)


How to classify vasculitis:

May classify by vessel size, by complement levels, by ANCA associated or not, and other features. Most commonly vessel size (Chapel Hill classification)

Large: Takayasu's, GCA

Medium: Kawasaki's, isolated CNS

Medium +/- small: PAN, Churg-Strauss, Wegener's

Small: HSP, cryoglobulinemia, hypersensitivity, microscopic polyangiitis


Basic features of some vasculitides (not intended to be exhaustive!)

Takayasu's:
pulse deficits, fever, malaise; may cause aortitis or dissection

Giant cell:
>50, sudden onset of pain, stiffness, fever, temporal h/a. Often pulse deficits, aortitis, aortic insufficiency

Kawasaki's
children with acute onset rash, fever, conjunctivitis. Often associated with coronary arteritis

Wegener's
fatigue, malaise, fever, inflammation of sinuses, kidneys, lungs. Also often cutaneous vasculitis. Often cANCA +ve

Microscopic polyangiitis
leukocytoclastic vasculitis, glomerulonephritis, hemoptysis, abdo pain. Often p-ANCA +ve

Churg-Strauss
Asthma, eosinophilia. Renal involvement is rare. p-ANCA often +ve

PAN
Assoc with HBV or HCV antigenemia. Fatigue, HTN, fever, renal failure, rash, mononeuritis multiplex. Marked HTN is classic for acute onset. May present as testicular pain.


Non-vasculitic causes of ANCA positivity

IBD, autoimmune hepatitis, CF, TB, many drugs (esp. PTU, methimazole, hydralazine, minocycline).

Some references for vasculitis diagnosis and management

http://www.bmj.com/cgi/content/full/338/apr22_2/b1461

http://jama.ama-assn.org/cgi/content/full/298/6/655

http://content.nejm.org/cgi/content/short/348/4/333