[Major thrombocytosis associated with severe anemia in children. Diagnosis of 9 cases].

Major thrombocytosis associated with severe anemia is uncommon in pediatrics. We report 9 consecutive cases observed in Albert Royer Children Hospital of Dakar. They were 7 boys and 2 girls 4 to 15 years old (mean age = 10 years). Six patients had a history of geophagia and 3 presented recent emission of worms by the stools. Anemia was clinically well tolerated in all cases. In initial blood count platelet levels varied from 800 10(3) to 1180 10(3)/mm3 (mean = 1032 10(3)/mm3), while hemoglobin level varied from 3.4 to 7.4 g/dl (mean = 4.9 g/dl). Anemia was microcytic, hypochromic and associated with low serum iron level in all patients. We considered the diagnosis of reactive thrombocytosis induced by iron deficient anemia in all cases. Platelet count and red cell indices were progressively normalised with iron treatment and no complication of thrombocytosis was observed. Considering published data, iron deficiency is one of the most frequent causes of reactive thrombocytosis in children. The physiopathologic mechanism, still unknown, could involve cytokines of thrombopoiesis. Reactive thrombocytosis induced by iron deficiency or other factors have usually a benign course and need no specific treatment other than that of the etiology.