Lec 01. Disorders of Primary Hemostasis: Vascular Disorders

thrombosis

formation of intravascular clots

petechiae

<3 mm hemorrhages into skin of different sizes

purpura

1 cm hemorrhages into skin of different sizes

ecchymosis

>3 cm hemorrhages into skin of different sizes

telangiectasia

chronic dilation of the capillary walls

menorrhagia

excessive menstrual bleeding

metorrhagia

irregular uterine bleeding not related to menstruation

hematohidrosis

sweating of blood

epistaxis

nosebleed

hematemesis

vomiting of blood

hemoptysis

expectoration of blood

hemarthrosis

leakage of blood into the joint cavity

hematochezia

passage of fresh blood in stool

melena

passage of old blood in stool

purpura

group of petechiae

vascular disorders

the pathophysiology of disorders of vessels and their supporting tissues is obscure

normal

results of laboratory studies of platelets and blood coagulation in vascular disorders

vascular disorders

diagnosis is often based on medical history and is made by ruling out other sources of bleeding disorders

• bruise easily

• bleed spontaneously

usual clinical sign of vascular disorders

1. Hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome)

2. Hemangioma-thrombocytopenia syndrome (Kasabach-Merritt syndrome)

3. Ehlers-Danlos syndrome

4. Homocystinuria

5. Pseudoxanthoma Elasticum

6. Osteogenesis Imperfects (brittle bone disease)

7. Marfan syndrom

Hereditary Vascular Disorders

Rendu-Osler-Weber Syndrome

Hereditary hemorrhagic telangiectasia

Rendu-Osler-Weber syndrome

• autosomal dominant

• telangiectasias (dilated superficial blood vessels that create focal red lesions) occur throughout the body — most obvious on face, lips, tongue, conjunctiva, nasal mucosa, fingers, toes, and trunk under the tongue

Rendu-Osler-Weber syndrome

• telangiectasias are fragile & prone to rupture

• lesions blanch when pressure is applied

• manifested by puberty

Rendu-Osler-Weber syndrome

diagnosis is based on the characteristic skin or mucous membrane lesions, a history of repeated hemorrhage, and a family history of a similar disorder

Kasabach-Merritt syndrome

Hemangioma-thrombocytopenia syndrome

Kasabach-Merritt syndrome

external hemangiomas may become engorged with blood and resemble hematomas

Kasabach-Merritt syndrome

condition present at birth

Ehlers-Danlos syndrome

may be transmitted as an autosomal dominant, recessive, or X-linked trait

Ehlers-Danlos syndrome

manifested by hyperextensible skin, hypermobile joints, joint laxity, fragile tissues, and bleeding tendency

Ehlers-Danlos syndrome

disorder generally can be ascribed to defects in collagen production, structure, or cross-linking, with resulting inadequacy of the connective tissues

homocystinuria

disorder of methionine metabolism, leading to an abnormal accumulation of homocysteine and its metabolites (homocysteine, homocysteine-cysteine complex, and others) in blood and urine

homocystinuria

increasing visual problems may lead to diagnosis of

Pseudoxanthoma Elasticum

progressive disorder characterized by accumulation of deposits of calcium and other minerals (mineralization) in elastic fibers

Pseudoxanthoma Elasticum

• yellowish bumps on skin of the neck, under the arms, and groin area

• periodic weakness in the legs (claudication)

• bleeding in GIT, particularly stomach

Osteogenesis Imperfecta

autosomal dominant disorder that prevents the body from building strong bones

Brittle Bone Disease

people with Osteogenesis Imperfecta might have bones that break easily, so it’s commonly called

Marfan Syndrome

affects connective tissue — fibers that support and anchor the organs & other structures in the body

Marfan syndrome

tall & thin w/ unusually long arms, legs, fingers, and toes

Henoch-Schoenlein purpura

allergic purpura

Allergic pupura (Henoch-Schoenlein purpura)

primary a disease of children, occurring most commonly in children 3-7 years old

Allergic purpura (Henoch-Schoenlein purpura)

relatively uncommon among individuals <2 years old & >20 years old

Allergic purpura (Henoch-Schoenlein purpura)

2x as many as boys as girls are affected

Allergic purpura (Henoch-Schoenlein purpura)

result of allergic vasculitis which involves the skin, GIT, kidneys, heart, and CNS

Allergic purpura (Henoch-Schoenlein purpura)

appearance of lesions: very rapid & accompanied by itching

Palpable purpura

lesions of Allergic purpura (Henoch-Schoenlein purpura) have been described as

Allergic purpura (Henoch-Schoenlein purpura)

• normal platelet count, bleeding time, blood coagulation

• elevated WBC & ESR

Paraproteinemia

high conc. of paraprotein can cause severe hemorrhagic manifestations as a result of a combination of hyper viscosity & platelet dysfunction

• IgA myeloma

• Waldenstrom macroglobulinemka

• IgG myeloma

Paraproteinemia is a platelet function abnormalities seen in

Paraproteinemia

poor correlation between abnormal results of protine, apt, thrombin time, bleeding time, & clinical bleeding

reduction in level of paraprotein

treatment for bleeding complications of Paraproteinemia is primarily:

Amyloid

fibrous protein consisting of rigid, linear, branching, aggregated fibrils approx. 7.5-10 nm wide and if indefinite length

Amyloidosis

thrombosis & hemorrhage have been ascribed to amyloid deposition in the vascular wall surrounding tissues

Amyloidosis

low factor X levels from binding of factor X to amyloid fibrils, hyperfibrinolysis related to excessive urokinase activity & platelet function alterations may enhance bleeding tendencies

Senile purpura

• occurs more commonly in elderly men

• due to lack of collagen support for small blood vessels & loss of subcutaneous fat & elastic fibers

Senile purpura

• dark blotches are flattened

• about 1-10 nm in diameter

• do not blanch with pressure

• resolve slowly, often leaving a brown stain in the skin (age spots)

Senile purpurs

laboratory tests are normal & no other bleeding manifestations

Drug-induced vascular purpuras

purpura associated w/ drug-induces vasculitis occurs in the presence of functionally adequate platelets

• aspirin

• warfarin

• barbiturates

• diuretics

• digoxin

• methyldopa

• sulfonamides

• iodides

drugs that induce vascular purpuras

Vitamin C deficiency (scurvy)

insufficient dietary intake of Vit C —> scurvy & decreased synthesis of collagen, w/ weakening of capillary walls & the appearance of purpuric lesions (normal lab test results)

unknown origin

purpura simplex, psychogenic purpura disease nature

purpura simplex (easy bruisability)

• inc. bruising that results from vascular fragility

• usually affects women

Gardner-Diamond syndrome, auto erythrocyte sensitization, or painful bruising syndrome

psychogenic purpura is referred to as

psychogenic purpura

• rare & poorly understood clinical presentation

• patients develop unexplained painful bruises, mostly on the extremities and/or face, during times of stress

factitious purpura

self-induced trauma and by pinching or suction

Schamberg’s purpura

development of cayenne pepper petechaie usually seen in diabetic patients