Churg–Strauss syndrome

• also known as eosinophilic granulomatosis with polyangiitis [EGPA] or allergic granulomatosis) is an autoimmune medium and small vessel vasculitis in persons with a history of airway atopy; pulmonary-renal syndrome

share many features with PAN, so think of PAN in an asthmatic patient

• first described in the early 1950s by Dr. Jacob Churg and Dr. Lotte Strauss (hence the original name, the Churg–Strauss syndrome)

The American College of Rheumatology 1990 criteria for diagnosis of Churg-Strauss Syndrome lists the following criteria:

1. Asthma
2. Eosinophils greater than 10% of a differential white blood cell count
3. Presence of mononeuropathy or polyneuropathy
4. Non-fixed pulmonary infiltrates
5. Presence of paranasal sinus abnormalities
6. Histological evidence of extravascular eosinophils

For classification purposes, a patient shall be said to have Churg–Strauss syndrome (CSS) if at least 4 of these 6 criteria are positive. The presence of any 4 or more of the 6 criteria yields a sensitivity of 85% and a specificity of 99.7%.

• Wegener's is closely associated with c-ANCA, while Churg-Strauss can be associated with elevations of p-ANCA.

Five-point system ("five-factor score" or FFS) that predicts the risk of death in Churg–Strauss syndrome using clinical presentations. These five factors are:

• Reduced renal function (creatinine >1.58 mg/dL or 140 μmol/l)
• Proteinuria (>1 g/24h)
• Gastrointestinal hemorrhage, infarction or pancreatitis
• Involvement of the central nervous system
• Cardiomyopathy

The lack of any of these factors indicates milder case, with a five year mortality rate of 11.9%. The presence of 1 factor indicates severe disease, with a five year mortality rate of 26%, and 2 or more very severe disease: 46% 5 year mortality rate.