| • | AKA allergic granulomatosis and angiitis |
| • | asthma – precedes other manifestations; onset at a later age than common asthma |
| • | peripheral eosinophilia - > 1500/mm3 |
| • | systemic vasculitis affecting 2 or more extrapulmonary organs; fever |
ARA criteria (4 of 6):
| • | a defining feature of CSS |
| • | precedes other manifestations |
| • | in contrast to common asthma, it develops at a later age |
| 2. | eosinophilia (>10% of WBC) |
| 4. | non-fixed pulmonary infiltrate |
| 5. | paranasal sinus abnormalities |
| 6. | extravascular eosinophils on biopsy |
| • | skin – the most distinctive, however not pathognomonic, cutaneous manifestations are tender nodules occurring primarily on the scalp and extremities, which resolve with scarring |
| • | major cause of mortality = cardiac failure (granulomatous infiltration of the myocardium resulting in restrictive cardiomyopathy and coronary artery vasculitis causing MI are both described) |
| • | renal failure occurs much less frequently in CSS compared with other major vasculitides |
| • | significant overlap with WG and PAN (i.e. the other “medium vessel vasculitides”) |
| • | labs – eosinophilia >10%; ANCA (+) (80% of the time) |
| • | p-ANCA (= vs. myeloperoxidase) – 70% |
| • | c-ANCA (= vs. proteinase 3) – 10% |
| • | treatment: systemic steroids – life saving by preventing irreversible organ damage |
histology:
| • | small arterial vessels affected preferentially |
| • | nodular lesions: characteristic extravascular granulomas |
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