[Acute infectious lymphocytosis associated to Giardia lamblia and Blastocystis hominis coinfection].

Acute infectious lymphocytosis is characterized by marked peripheral blood lymphocytosis, often associated with a mild, nonspecific febrile illness. We present a 4-year-old girl with acute infectious lymphocytosis associated with Giardia lamblia and Blastocystis hominis coinfection. Analysis of peripheral lymphocyte markers showed overall proliferation of B and T cells with a reduction in the proportion of T cells, especially in the CD4T cell subpopulation. Hematologic values returned to normal after treatment with metronidazole.