Drug-induced immune-mediated thrombocytopenia

Dear Sir, A 24‐year‐old female presented with acute onset of multiple petechial skin rashes all over the body along with subconjunctival hemorrhages in both eyes and hematuria for 2 days. Hematological investigations showed hemoglobin of 6.5 g/dL and platelet count of 10 × 109/L with normal total leukocyte count of 5.82 × 109/L. Peripheral blood film did not show any atypical cells, and a subsequent bone marrow biopsy was also normal. She was receiving anti‐tubercular therapy (ATT) namely rifampicin (R), isoniazid (H), pyrazinamide (Z), and ethambutol (E) for the past 2 weeks for tubercular pleural effusion. Her platelet count was 228 × 109/L at the time of diagnosis of tuberculosis and before starting ATT. She had no other comorbidities. She did not have coagulopathy and antinuclear antibody & indirect Coomb test were negative. She was tested negative for hepatitis B, hepatitis C, and human immunodeficiency virus serology. Serum Vitamin B12 and folic acid levels and ultrasonography of the abdomen were also normal. A possibility of drug‐induced thrombocytopenia (DIT) was kept, and all the four anti‐tubercular drugs were stopped. However, platelet counts did not improve even after giving transfusion of multiple random donor platelets and single‐donor apheresis platelets, rather her platelet count decreased further up to 5 × 109/L. A possibility of immune‐mediated peripheral destruction of platelet was kept, and she was given oral prednisolone (1 mg/kg/day) and the platelet count improved to 100 × 109/L after 7 days of steroid induction with resolution of the bleeding manifestation. A diagnosis of ATT‐induced immune‐mediated thrombocytopenia was made, and all the four anti‐tubercular drugs (HRZE) were restarted in full dose and the dose of steroid was gradually tapered and subsequently stopped. Her platelet count was 325 × 109/L on ATT 7 days after stopping steroid, and she did not have any further recurrence of thrombocytopenia.