Dapsone: An Old but Effective Therapy in Pediatric Refractory Immune Thrombocytopenia.

There are no definitive guidelines for management of chronic or refractory immune thrombocytopenia (ITP) in children. Dapsone is an inexpensive and efficacious, yet neglected, therapeutic option for treatment of chronic ITP. We evaluated the efficacy and safety of dapsone in the management of chronic ITP in children. Children with chronic ITP < 14 years with minimum grade 2 bleeds refractory to either splenectomy/rituximab/eltrombopag; who were offered dapsone therapy were retrospectively analyzed. Dapsone intolerance and G6PD deficiency were excluded. Dapsone was started at a dose of 1-2 mg/kg/day. Response to dapsone as per international working group definitions, time to response along with side-effects were noted. Forty-four children enrolled; 29 analyzed. Nineteen were refractory to rituximab, 8 to splenectomy and 6 to eltrombopag. Median age was 9.8 years (3-14) with 16/29 males. Median dapsone dose was 1.59 mg/kg/day (range 1-2.1). Overall response was seen in 21/29 (72%): Complete Response in 7/29 (24%), Partial Response in 14/29 (48%). All responses were sustained for minimum 3 months. Median duration to response was 2.9 months (2-6.6). Median follow up was 28 months (6-73) and relapse rate-21%. Major side effects noted: Methemoglobinemia-01, skin ulceration-02. In three cases dapsone could be tapered and stopped without relapse. Dapsone is an economical and efficacious agent with good safety profile in childhood chronic/refractory ITP.