Hemophagocytic lymphohistiocytosis caused by primary Epstein-Barr virus in patient with Crohn's disease.

We present a case of a 19-year-old man with a 6-year history of Crohn's disease (CD), previously treated with 6-mercaptopurine, who was admitted to our department for Epstein-Barr virus (EBV) infection and subsequently developed a hemophagocytic lymphohistiocytosis (HLH). HLH is a rare disease which causes phagocytosis of all bone marrow derived cells. It can be a primary form as a autosomic recessive disease, or a secondary form associated with a variety of infections; EBV is the most common, the one with poorer prognosis. The incidence of lymphoproliferative disorders was increased in patients with inflammatory bowel disease (IBD) treated with thiopurines. Specific EBV-related clinical and virological management should be considered when treating a patient with IBD with immunosuppressive therapy. Moreover EBV infection in immunosuppressed patient can occur with more aggressive forms such as encephalitis and diffuse large B cell lymphoma. Our case confirms what is described in the literature; patients with IBD, particularly patients with CD receiving thiopurine therapy, who present 5 d of fever and cervical lymphadenopathy or previous evidence of lymphopenia should be screened for HLH.