From the Guidelines
Laboratory workup for pediatric nosebleeds should be selective and guided by clinical presentation, with no routine testing necessary for most isolated, uncomplicated cases. For most children with nosebleeds, the cause is typically due to local factors like digital trauma, dry air, or minor trauma, and thus, no laboratory testing is necessary 1. However, when nosebleeds are recurrent, severe, difficult to control, or associated with concerning symptoms, laboratory evaluation may include:
- Complete blood count (CBC) to assess for thrombocytopenia or anemia
- Coagulation studies (PT/INR, PTT) to evaluate for bleeding disorders
- Von Willebrand factor assays if a bleeding disorder is suspected In cases of significant blood loss, hemoglobin and hematocrit should be checked. The American Academy of Pediatrics suggests that if a laboratory evaluation is conducted, tests should be chosen based on the prevalence of the condition, patient and family history, ease of testing, blood volume required for testing, and probability of a bleeding disorder causing the condition 1. For children with systemic symptoms or family history of bleeding disorders, more extensive testing may be warranted, including factor assays. The timing of these tests is important - they should be performed before significant blood loss occurs to avoid dilutional effects. This targeted approach helps identify underlying conditions like coagulopathies, platelet disorders, or hematologic malignancies while avoiding unnecessary testing in straightforward cases.
From the Research
Pediatric Nosebleed Workup Labs
When evaluating a pediatric patient with a nosebleed, the following lab tests may be considered:
- Complete Blood Count (CBC) with differential count and reticulocyte count to help narrow the differential diagnosis and tailor the subsequent evaluation 2
- Prothrombin Time (PT) and activated partial thromboplastin time (aPTT) to assess coagulation pathways 3, 4, 5, 6
- International normalized ratio (INR) to evaluate extrinsic coagulation pathway 6
- Fibrinogen assay to assess coagulation factor levels 4, 6
- Bleeding time (BT) test, although less commonly performed, to evaluate platelet function 3, 5
Initial Evaluation
The initial evaluation of a pediatric patient with a nosebleed should include a comprehensive history, physical examination, and laboratory testing to identify potential causes of abnormal bleeding 6. A bleeding assessment tool and patient-provided photographs can also aid in diagnosis 6.
Laboratory Testing
Laboratory testing for pediatric nosebleed workup may include:
- PT and aPTT to assess coagulation pathways 3, 4, 5, 6
- CBC with differential count and reticulocyte count to evaluate blood cell counts and morphology 2
- Fibrinogen assay to assess coagulation factor levels 4, 6
- INR to evaluate extrinsic coagulation pathway 6
Consultation
Consultation with a hematologist is recommended when initial evaluation indicates a bleeding disorder or when suspicion remains high despite a normal laboratory workup result 6.