Bruising and Blood Disorders

Disseminated Intravascular Coagulopathies are a group of disorders that affect clotting or thrombosis. These disorders come in both genetic and acquired forms and are not easily diagnosed. Coagulation Disorders produce increased vascular permeability and a decreased ability to clot after suffering a subdural hematoma. Unfortunately, because most of the clotting and complement disorders can only be tested on circulating blood, it is nearly impossible to determine retrospectively, during autopsy, whether a child had a clotting disorder that exacerbated or caused a subdural hematoma.

A. Thrombocytopenia (TCP) is a coagulopathy defined by platelet counts less than 100,000/mm of blood. Platelet counts of less than 50,000 have been associated with bleeds from minor trauma whereas platelet counts between 10,000-15,000 results in spontaneous hemorrhages. TCP can travel with other congenital conditions, such as TCP with Absent Radii (TAR) syndrome, May Hegglin Syndrome, Wiskott-Aldrich Syndrome, and Autosomal Recessive TCP. TCP can also be idiopathic. Ideopathic or immune TCP is caused by an autoimmune process which destroys platelets. It is found in 1 in 10,000 people. Ideopathic TCP is generally diagnosed from bruises or petichae on the body or mucosa sinuses, bleeding gums, epistaxis hematuria, menorrhagia, weight loss, fever, and headache. Treatment includes prednisone or splenectomy. TCP has three major causes:

1. Decreased bone marrow production: Can be tested by bone marrow biopsy. Generally affects hemopoeisis so may be accompanied by varying degrees of anemia or luekopenia.

2. Splenic Sequestration Abnormalities: Check for enlarged spleen. Most common cause is portal hypertension secondary to liver disease.

3. Accelerated Distraction: Abnormal vessels, fibrin thrombi or intravascular prostheses can all shorten the life span of a platelet and cause non-immunologic TCP.

a) Drug Induced TCP:
Most patients recover within 7-10 days. Some more
severely affected patients require platelet transfusions or temporary support with glucocorticoids or plasmapheresis. Patients are warned to avoid the offending drug in the future because even "minute" amounts of the drug are needed to set up subsequent immune reactions. Heparin is highly suspect to cause TCP and is more common in Heparin derived from beef lung. Vaccines have been shown to produce such results

b) Idiopathic TCP:
90% of the pediatric cases of immunologic TCP are seen following a recovery from upper respiratory illness or from a "viral exanthem." Acute idiopathic TCP generally recovers in 4-6 weeks though some cases take 3-6 months

B. (Thrombocythemia (i.e. Thrombocytosis) is a coagulopathy characterized by platelet counts greater than 400,000. Both forms of TCC can cause hemorrhages in the veins of the skin, stomach, eyes, brain and vital organs

1. Primary Throbocythemia(TCC) is a condition where platelets are produced in greater number than usual.

2. Secondary Thrombocytopenia is more rare and more difficult to diagnose. It follows splenic atrophy, malignancy of the lungs etc. or chronic blood loss.

C. Von Willebrands Disease (VWD) is the most common inherited bleeding disorder. This disorder is characterized by a decreased production of Von Willebrand factor, (VWF) does two things.

1. Facilitates platelet adhesion under conditions of high shear stress by linking platelet membrane receptors to vascular subendothelium. Normal VWF levels are 10mg/L. "A modest reduction in VWF concentration or selective loss of high-molecule weight multimeters, decreases platelet adhesion and causes clinical bleeding."

2. Serves as a plasma carrier for factor VIII the antihemophilic factor that facilitates coagulation.