Diagnosis

The criteria for diagnosis of this syndrome has been outlined by the American College of Rheumatology. The six classification criteria identified in the study were: (1)

• asthma
• peripheral blood eosinophilia
• neuropathy
• pulmonary infiltrates
• paranasal sinus involvement
• biopsy showing vasculitis with extravascular eosinophils

The presence of four of these criteria permitted discrimination of Churg-Strauss syndrome from other vasculitides with a sensitivity of 85% and a specificity of 99.7%.

Laboratory diagnosis is based on tissue biopsy and the antineutrophil cytoplasmic antibody (ANCA) test

• serologically, the prevalence of ANCA is anti-MPO pANCA 60% and anti-PR3 cANCA 10% and undetected in the remaining 20% (2)

This syndrome is also characterised by elevated levels of IgE.

Reference:

1. Jennette JC et al. Nomenclature of systemic vasculitides. Proposal of an international consensus conference. Arthritis Rheum. 1994 Feb;37(2):187-92