Abstract
Background: Churg-Strauss syndrome (CSS) is potentially fatal, unless promptly diagnosed. The American College of Rheumatology (ACR) requires fulfillment of four of six criteria (asthma, eosinophilia, neuropathy, pulmonary opacities, paranasal sinusitis, and vasculitis with eosinophilic infiltration) for diagnosis. An association between CSS and production of interleukin (IL)-5, IL-13, and eotaxin-3 has been reported.
Case Report: A 66-year-old man, with asthma and sinusitis, presented with high fever, abnormal limb sensations, diarrhea, and palpable purpura. He had been administered glucocorticoids and suplatast tosilate (Th2 cytokine inhibitor). Purpura and intestinal mucosa biopsy revealed vasculitis with eosinophilic infiltration. Computer tomography revealed lung involvement. All ACR criteria for CSS, except peripheral eosinophilia, were fulfilled. Since CSS without eosinophilia is very rare, diagnosis was not prompt. Symptoms subsided after steroid pulse therapy. Subsequently, extremely high IL-5, IL-13, and eotaxin-3 were detected. After the steroid pulse, these became undetectable.
Conclusions: These cytokines supported CSS diagnosis and may be used as biomarkers. Prior medication of glucocorticoid and suplatast tosilate may have suppressed peripheral eosinophilia. This is the first case of CSS without eosinophilia, in which the clinical picture and cytokine profile were reported in detail. Therefore, this report will provide useful insight into the differential roles of individual cytokines in CSS pathogenesis.

Keywords: Churg-Strauss syndrome, Eosinophilia, suplatast tosilate, Interleukin-5, Interleukin-13, Eotaxin-3, Interleukins, Eotaxins, cytokine