An increased risk of thrombosis has been described in patients with hypereosinophilic syndromes, including Churg-Strauss syndrome (CSS).
We report the case of a 43-year-old man with CSS who presented with asthma, pansinusitis, blood eosinophilia (9650/μL), peripheral neuropathy, cutaneous eosinophilic vasculitis, and a positive result for antineutrophil cytoplasmic antibodies. An analysis of plasma during active disease revealed elevated levels of prothrombin fragment 1+2 (marker of thrombin generation) (832 pM; normal range, 68-229 pM)
and D-dimer (marker of fi brin degradation) (2300 ng/mL; normal range, 130-250 ng/mL), which indicate an increased risk of thrombosis.
Both parameters returned to normal values during remission after immunosuppressive treatment. Skin histology showed leukocytoclastic vasculitis with numerous eosinophils in the dermal infi ltrate. Immunohistochemistry revealed expression of tissue factor by skin-infiltrating eosinophils, as confirmed by colocalization with eosinophil cationic protein, a classic marker of eosinophil granulocytes. In conclusion, we present a patient with active CSS and a prothrombotic state that reverted during remission achieved by immunosuppressive therapy.

Key words: Churg-Strauss syndrome. Eosinophil. Tissue factor. Thrombosis.