A 9-year-old boy is brought to the emergency department by his parents due to prolonged bleeding following a
tooth extraction earlier in the day. Past medical history is noncontributory. Temperature is 37.5°C (99.5°F),
pulse is 88/min, respirations are 14/min, and
blood pressure is 112/62 mmHg. Physical exam shows
gingival bleeding and
petechiae. Laboratory testing is obtained, and the results are shown below.
| Laboratory value | Result |
| Hematologic | |
| Hemoglobin | 12 g/dL |
| Hematocrit | 40% |
| Platelet count | 95,000/mm3 |
| Leukocyte count | 9,000/mm3 |
| Coagulation studies | |
| Prothrombin time (PT) | 12 seconds |
| Activated partial thromboplastin time (aPTT) | 29 seconds |
| Bleeding time* | 15 minutes |
*Reference Range: 2-7 minutes
Which of the following conditions is the patient at greatest risk of developing?
