Systemic inflammatory response syndrome (SIRS) can be related to acute inflammatory conditions that can be sometimes missed and inappropriately managed as severe infections. We report a case of Churg Strauss Syndrome (CSS), presenting as septic shock with acute onset of fever and multiple organ failure including pulmonary involvement with severe hypoxemia, hypotension requiring vasoactive support and acute renal failure. Antibiotics were discontinued and intravenous steroids allowed a rapid clinical improvement in close relationship with the fall in circulating eosinophils count.