Q fever as a rare cause of hemophagocytic lymphohistiocytosis: Case report.

Hemophagocytic Lymphohistiocytosis (HLH) is a reactive disorder of the mononuclear phagocytic system characterized by increased histiocytic proliferation, activation and hemaphagocytosis. The underlying etiology may be genetic (primary) or acquired (secondary). Secondary causes include drugs, autoimmune diseases, malignancies and infections of which EBV is the most common. A 28-year old male patient who was a shepherd with no known concomitant comorbid disease was admitted to the Emergency Department with the complaints of abdominal pain, fever, severe fatigue. Physical examination revealed high fever, hepatosplenomegaly and laboratory examination revealed pancytopenia, hyperferritinemia and hypertriglyceridemia. Hemophagocytes were observed in the bone marrow biopsy and the patient was diagnosed as HLH. The patient was treated with cyclosporine A, dexamethasone, intravenous immunoglobulin (IvIg) and etoposide according to the HLH 2004 protocol. Coxiella burnetii was detected in the serological evaluation of the etiology and doxycycline was added to the current treatment. Fever was controlled in the second week of the treatment and the patient was discharged after complete recovery of the cytopenia in the fourth week. In the outpatient setting, treatment was completed in 8 weeks and follow-up of the patient is still ongoing without medication. To the best of our knowledge, this is the first case from Turkey of HLH secondary to Q-fever which was treated and managed successfully. Since the mortality of HLH is quite high, the etiology should be determined as soon as possible to be able to provide appropriate treatment.