Churg–Strauss syndrome (CSS) is a rare systemic vasculitis characterized by hypereosinophilia, necrotizing vasculitis with granulomas of extravascular eosinophils and asthma history [1]. CSS has also been shown to be a pathological syndrome of angiitis and allergic granulomatosis [2]. Three principal classifications are described

Lanham’s criteria which depend upon clinical aspects [1].

Chapel Hill Consensus Conference [3].

The American College of Rheumatology that has suggested 6 criteria from which 4 are required for a diagnosis of CSS with 99.7% specificity and 85% sensitivity. The 6 criteria include asthma, eosinophilia > 10%, paranasal sinusitis, vasculitis based on histology, and mononeuritis multiplex [4].

Vasculitis lesions of CSS on histological examination are not typically seen in biopsies and are not specific for CSS; at the same time their absence is not cause to reject a diagnosis of CSS [5].