A 6-month-old boy presents to your office after his mother notices swelling and ecchymosis over his anterior right thigh. She does not recall any trauma to the area. The mother denies any history of bleeding problems, including during his circumcision. On physical examination the child has a large hematoma over his thigh. There are no obvious bony deformities and the child otherwise looks well. You suspect the child may have an inherited coagulation disorder.
Question 6.1.1 Which of the following statements is NOT correct?
A) Child abuse should be included in the differential diagnosis.
B) The child did not bleed during circumcision, so the possibility of hemophilia need not be considered.
C) A careful family history is important in the work-up.
D) Coagulation studies (PT, PTT) and CBC should be obtained.
Answer 6.1.1 The correct answer is "B." The absence of bleeding during circumcision in no way rules out hemophilia. Up to half of hemophiliac patients do not bleed after circumcision. Depending on the severity of factor deficiency, the diagnosis may not be made until the child is very active or even in adulthood, after surgery, etc.
Question 6.1.2 Which of the following is NOT TRUE about hemophilia A?
A) It is an X-linked disorder.
B) It is the result of factor VIII deficiency.
C) It generally leads to mucosal bleeding.
D) It occurs most often in males.
E) It can be treated with factor VIIa
Answer 6.1.2 The correct (and wrong) answer is "C." Hemophilia A is an X-linked deficiency of factor VIII, which presents with hematomas, bleeding, and hemarthrosis (and not generally mucosal bleeding or petechiae). Deficiency of factor IX, or hemophilia B, also known as "Christmas Disease," is also X-linked but is much less common. "D" deserves special mention. Hemophilia rarely occurs in females but can occur in two situations: (1) the female patient is a heterozygote who has early inactivation of the second X chromosome during embryogenesis or (2) if both parents are carriers—in which case the father would have the disease overtly. "E" is true. Factor VIIa can be used in most cases of hemophilia A and B to stop bleeding. It is mostly used in patients who have factor inhibitors in the blood (developed as a response to repeated exposure to factor VIII or factor IX [Christmas disease]).
Generally speaking, petechiae and mucosal bleeding result from platelet problems (e.g., mild von ...