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The Best in FOAM Education

  • Timothy Khowong, MD

A Brief Approach to Petechial Rash

A 6 year old female with no PMH is brought into the ED by her parents. She has had 1 week of malaise, somewhat decreased activity, low grade fevers, and a few days of progressively worsening petechial rash that started on the trunk and became more widespread to the mouth, arms, and legs. ROS otherwise negative. No abdominal pain, urinary symptoms, or sore throat.

On exam, her vital signs are within normal limits. She is afebrile but you notice scattered petechiae on the entire body and oral mucosa, sparing the palms and soles. Otherwise unremarkable, patient is well-appearing, without localizing infectious signs.

Differential Diagnosis

Most likely:

  • ITP

Cannot miss:

  • Sepsis/meningococcemia

  • HUS

  • TTP

  • DIC

  • Bone marrow failure

  • Malignancy

  • Hemophilia

  • Vasculitis


  • vWF disease

  • Vitamin K deficiency

  • Vitamin C deficiency

  • Factor deficiencies

Work Up

Definitely: CBC with differential, Chem 8, hepatic panel, coagulation panel

Consider (based on history): Blood cultures, RVP, reticulocyte count, LDH, haptoglobin, ESR/CRP

Results demonstrated thrombocytopenia with a platelet count of 1K (nml 150K - 350K). Otherwise unremarkable. Coags WNL. Hematology consulted. They recommend admission for IVIG vs steroids.


Admitted to Pediatric Hematology/Oncology service.

Hospital Course

During admission, patient received IVIG without response. She was started on steroids with improvement in platelet counts. Ultimately she had to have platelet transfusion. Bone marrow biopsy was negative for malignancy. She was discharged home and is now doing well.

Take Away #1

Purpura/petechiae are indicative of either small vessel damage, dysfunction in the coagulation cascade, or severe thrombocytopenia.

Take Away #2

History, vital signs, general appearance of the child will guide you towards the appropriate work-up. VS abnormalities/ill appearing in a child with thrombocytopenia should be setting off alarm bells.

Take Away #3

Even if the patient is well appearing now, spontaneous hemorrhage can occur in profound thrombocytopenia, especially in platelet counts <15K. In children, prevent them from falling, hitting their head, and picking their noses. Platelet transfusion may or may not be indicated based on the underlying condition.


Timothy Khowong is a current second year resident at Stony Brook Emergency Medicine.


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