Severe neutropenia revealing a rare presentation of dengue fever: a case report.

Background: Arboviruses are a common cause of fever in the returned traveler often associated with leucopenia, especially lymphopenia and thrombocytopenia. Transient neutropenia has been described in a few cases of arboviruses. However, prolonged and severe neutropenia (<500/mm) has rarely been reported in dengue fever, especially in the returned traveler in Europe.

Case Presentation: A 26-year-old healthy female without any medical past history, flying back from Thailand, presented a transient fever with severe neutropenia (<500/mm). Laboratory tests showed a mild hepatic cytolysis and thrombocytopenia, mimicking malaria or viral hepatitis. While she underwent protective isolation, NS1 antigen returned positive in favor of a dengue fever. Outcome was favorable without any antimicrobial therapy.

Conclusion: Physicians should be wary of possible unusual presentation of dengue fever with prolonged neutropenia. Although such biological sign is more often associated with malaria or severe bacterial infection, it may be a sign of arbovirus.