Case Presentation: An 8-year-old HIV-negative boy presented to a hospital in Malawi in septic shock secondary to typhoid fever with ileocecal perforation. He underwent repair and peritoneal washout without bowel resection. He was treated with ceftriaxone, metronidazole and supportive care. Initial labs were notable for hemoglobin of 10g/dl, platelets of 22/dL, and WBC 2.8/dL. Two days later his hemoglobin and platelets decreased to 7.2g/dL and 1/dL, respectively, requiring transfusions. Antibiotics were broadened to meropenem due to persistent fever and hypotension. Despite clinical improvement with these changes he remained persistently thrombocytopenic with petechiae and nosebleeds. His profound thrombocytopenia was initially attributed to bone marrow suppression related to his infection, however his other cell lines eventually normalized while platelets remained low. Blood smear showed a single giant platelet. The combination of isolated thrombocytopenia with lack of response to platelet transfusion suggested immune thrombocytopenic purpura (ITP), which has been reported in cases of typhoid fever. He was treated with methylprednisolone for 4 days with improvement in his platelet count to 67/dL. He was transferred to rehab where he continued to improve without recurrence of his ITP.
Discussion: Typhoid fever is caused by Salmonella enterica serotype Typhi and is endemic to Sub-Sarahan Africa. Classic features of the disease include fever, abdominal pain, and salmon-colored macules or “rose spots.” Left untreated, the infection can lead to ileocecal perforation resulting in sepsis and peritonitis. Anemia and leukopenia are commonly seen and typically improve with resolution of infection. Salmonella infection can also lead to bone marrow infiltration causing persistent pancytopenia. Additionally, there have been several case reports of typhoid-associated ITP with similar presentations and clinical courses as our patient. ITP is an immune-mediated destruction of platelets and is therefore refractory to platelet transfusion. Steroids remain the first line of treatment in pediatrics, although intravenous immune globulin (IVIg) is also used when available. Megakaryocytes are classically seen on blood smear, however this is not required as it is a diagnosis of exclusion.
Conclusions: It is important to consider alternative causes to thrombocytopenia in patients with typhoid fever, particularly when the other cell lines have improved and there is no effective response to transfusion. Typhoid-associated ITP is a rare, but documented occurrence, and patients can respond quite well to treatment with corticosteroids.