Question: A 19-year-old girl with no medical history of interest, except for a self-limiting flu-like illness 3 weeks before, who went to the Emergency Department for petechiae and spontaneously occurring bruising. On physical examination, the patient is in good general condition, afebrile, normotensive and oriented in time and space. Petechiae disseminated by EEII and small abdomen and ecchymoses are observed in decubitus areas. No enlarged adenopathy or splenomegaly. The analysis carried out offers the following findings: Hb 12.6 g / dL, Leukocytes 5,500 / mm3, platelets 7000 / mm3. The study of the peripheral blood smear offers a normal erythrocyte morphology, normal differential leukocyte count and the platelet count is concordant with the autoanalyzer figure without observing plaque aggregates. Biochemistry, proteinogram, beta 2 microglobulin and normal LDH. What do you think is the most appropriate initial treatment of the following? 
 Options:  <1> Platelet transfusion. <2> Rituximab in weekly schedule. <3> Cyclophosphamide in pulses of 4 days every 21 days. <4> Plasmapheresis daily. <5> Prednisone at 1 mg / day for 2-3 weeks.
5