Immune thrombocytopenic purpura is an isolated thrombocytopenia consisting of premature platelet destruction mediated by self-reacting antibodies and an impaired platelet production. In children, most of the cases resolve spontaneously within six months. Several studies have shown a high incidence of vitamin D deficiency in auto-immune disorders, including immune thrombocytopenic purpura. We report the clinical history of an eight-year-old boy who presented with refractory immune thrombocytopenic purpura and major vitamin D deficiency. Supplementation in vitamin D was followed by a rapid normalisation of thrombocytosis. After six months of evolution, the child developed a relapse of immune thrombocytopenic purpura concomitant with a decrease of his serum level of vitamin D. Treatment with vitamin D associated with dapsone resulted in a prolonged remission. After thirteen months, dapsone treatment was stopped and the platelet count remained normal. This article reviews the approach of refractory immune thrombocytopenic purpura in children and discusses the potential interest of vitamin D in this disease.

(BELG J HEMATOL 2018;9(2):64–7.)