Pathology
Bleeding tendencyHemorrhage and extravasations of blood from vascular spaces.
Causes:Vascular disorder.
Decrease platelet count.
Defect in platelet function.
Coagulative disorder
Tests used in the diagnosis of bleeding tendency:
Platelet count (NR 150-450 *109\L) CBPBleeding time ( NR 2-5 min )
Prolongation seen in thrombocytopenia or defect in platelet function , vonwillebrands disease , acquired vascular disorder.
3- clottimg time (NR :5-12)m .prolongation of clotting time occur in abnormality of clotting factors.
4- Prothrombin time (NR 5-12 sec) .
Prolong in defect of extrinsic factor as factor VII ( oral anticoagulant therapy , DIC , liver disease ).5-Activated partial thromboplastin time ( APTT ) (NR 30-40 sec )
Prolongation seen ii abnormality of intrinsic factor as haemophilia , parental heparin therapy , DIC , liver disease .
6- Assay of serum level of deficit factor.
Haemorrhagic diathesis due to vascular disorder
Normally mild , characterized by petechiae, purpura or ecchymosis confined to the skin & m.mMajority of screening tests are including bleeding time are normal
Could be congenital or acquired , the most common causes include :
Henoch schonlan purpura : ( self limited disease of children of hyper sensitivity vasculitis characterized by purpura , haematuria , colicky abdominal pain , polyarthralgia )
Infection: as in septicemia and measles.
Steroid purpura.
Senile purpura: seen in old age due to atrophy of supportive tissue of blood vessel.
Scurvy
Hemorrhagic diathesis due to platelets disorder due to reduction in the number or due to defect in function
Thrombocytopenia: which may result from:
Impaired in the production due to disease of bone marrow or a plastic anemia, leukemia, megaloblastic anemia or infiltration by malignancyIncrease in platelet destruction: as in idiopathic thrombocytopenia (ITP), drugs.
Hypersplemism
dilutional due to mass blood transfusion with old blood stored blood
ITP : acute , chronic
Acute:
Affect children, history of vaccination or infection, characterized by petichial haemorrhage easy bruising, epistaxis . spontaneous remission seen in 90% up to 6 months.Chronic ITP:
Usually seen in adult female (20-40 years), insidious persist for many years, usually idiopathic or may follow SLE, ch. Lymphocytic leukemia or Hodgkin disease, characterized by petechial bleeding , easy braising & menorrhagiaDX:
Bleeding time prolong ,clotting time is normal.
Platelet count reduced 10-50 * 109\L.
Blood film Show occasional platelet with normal RBC &WBC
B.M show increase in megakaryocyte
Anti platelet antibody
Coagulation disorder: Hereditary coagulation disorder: hemophilia A ,Christmas disease(hemophilia B) & vonwillbrand disease.
Acquired coagulation disorder: VK deficiency ,coagulation disorder due to liver disease &DIC.
Haemophilia A:
It is the second most common coagulation disorder, occur due to deficiency or reduce activity of factor VIII.Transmitted as sex-linked recessive so the disease is seen in male & female act as a carrier with few exception.
Clinically: patients suffer from bleeding for few hours after injury, recurrent bleeding in the joint (haemorthrosis) & muscle haematoma, Sometime hematuria
Investigation:
Clotting time is prolong in severe cases. Bleeding time is normal.
Platelets count is normal.
Prothrombin time is normal.
APTT is prolong.
VIII assay show lower activity & this test is useful for DX of carrier which show 50% reduce activity while symptomatic patient show 25% reduce activity.
Christmas disease (haemophilia B)
Rarer than haemophilia A.
Due to deficiency of factor IX.
Clinically &laboratory diagnosis is same as haem. A but except it show reduce activity of factor XI.
Vonwillebrand disease:
Most common hereditary disorder due to deficiency of vonwillebrand factor . It transmit as autosomal dominant.Clinically: spontaneous bleeding from M.M & excessive bleeding after trauma.
Investigation (laboratory finding)
Prolong bleeding time (due to defect in platelet function).
Clotting time prolong .
Platelets count is normal.
Reduce VWF concentration
Defective platelet aggregation with restocin , an antibiotic.
Reduce factor VIII activity.