Week 2 - Vascular Disorders Flashcards
Abnormal bleeding involving the loss of red blood cells from the microcirculation.
Purpura
Characterized by obvious hemorrhages into the skin and mucous membranes that appear as extensive areas of red or dark-purple discoloration.
Purpura
If small, purplish hemorrhagic spots on the skin or mucous membranes are evident, it is called.
Petechiae
If the patches of bleeding into the tissues are larger, this is referred to as
Ecchymosis
Hereditary Hemorrhagic Telangiectasia
Rendu-Osler-Weber Syndrome
Autosomal Dominant
Hereditary Hemorrhagic Telangiectasia
Rendu-Osler-Weber Syndrome
Characterized by thin-walled blood vessels.
Hereditary Hemorrhagic Telangiectasia
Rendu-Osler-Weber Syndrome
○ Discontinuous endothelium
○ Inadequate smooth muscle
○ Inadequate or missing elastin in the stroma
Hereditary Hemorrhagic Telangiectasia
Rendu-Osler-Weber Syndrome
Manifests by puberty and progresses throughout life.
Rendu-Osler-Weber Syndrome
Universal finding of Rendu-Osler-Weber Syndrome
Epistaxis
Mutations in the ENG gene.
Type 1 Hereditary Hemorrhagic Telangiectasia
Mutations in the ACVRL1 gene.
Hereditary Hemorrhagic Telangiectasia type 2
Unknown mutation of HHT
Hereditary Hemorrhagic Telangiectasia type 3
caused by mutations in the gene SMAD4.
Juvenile Polyposis/HHT
Dilated superficial blood vessels that create small,
focal red lesions.
Telangiectasia
The lesions blanch when pressure is applied.
Telangiectasia
● Most obvious on the face, lips, tongue, conjunctiva, nasal mucosa, fingers, toes, trunk, and under the tongue.
● Fragile and prone to rupture.
Telangiectasia
Diagnosis of HHT
Based on the consensus clinical criteria of Curacao.
Presence of 3 out of 4 criteria:
○ Spontaneous recurrent epistaxis
○ Cutaneous telangiectasia
○ Visceral involvement
○ Familial heredity
Other Disorders with Telangiectasia
Cherry-redhemangioma
Ataxia-Telangiectasia (Louis-Bar Syndrome)
Chronic Actinic Telangiectasia
Hemangioma-Thrombocytopenia Syndrome
Kasabach-Merritt Syndrome
Hereditary basis has not been established, but condition is present at birth
Hemangioma-Thrombocytopenia Syndrome
Kasabach-Merritt Syndrome
Giant hemangioma may occur
congenitally soon after birth or affect the skin, liver, and spleen.
Either visceral or subcutaneous, but rarely both.
Hemangioma-Thrombocytopenia Syndrome
Kasabach-Merritt Syndrome
External hemangiomas may become engorged with blood and resemble hematomas.
Hemangioma-Thrombocytopenia Syndrome
Kasabach-Merritt Syndrome
Giant Cavernous Hemangioma (Vascular Tumor)
Complications
Microangiopathic hemolytic anemia
Associated disease of Hemangioma Thrombocytopenia Syndrome
Giant Cavernous Hemangioma (Vascular Tumor)
Thrombocytopenia
Bleeding diathesis
Thrombocytopenia complications
Sequestration of platelets in hemangiomas
Bleeding Diathesis complications
Acute or chronic disseminated intravascular coagulopathy
Ehlers- Danlos Syndrome
Mode of inheritance:
Autosomal dominant
Autosomal recessive
X-linked trait
Can be ascribed to defects in collagen production.
Ehler danlos syndrome
Ehler Danlos Syndrome Manifestations
● Hyperextensible skin
● Hypermobile joints
● Joints laxity
● Fragile tissues
● Bleeding tendency
● Subcutaneous hematoma formation
EDS IV mode of inheritance
Autosomal dominant
Mode of inheritance of EDS
Greatest risk for major bleeding.
EDS Type4
Mode of inheritance of EDS
Structural defect in proa1(III) chain of collagen encoded by COL3A1 gene
EDS TYPE 4
Pseudoxanthoma Elasticum (PXE) other name
Groenblag-Strandberg Syndrome
Autosomal recessive
Pseudoxanthoma Elasticum (PXE)
Groenblag-Strandberg Syndrome
Inherited connective tissue disorder that results in calcification and mineralization of elastic fibers
Pseudoxanthoma Elasticum (PXE)
Groenblag-Strandberg Syndrome
Pseudoxanthoma Elasticum (PXE)
Groenblag-Strandberg Syndrome mutations
Mutations in the ABC-C6 gene.
Group of nonthrombocytopenic purpuras characterized by apparently allergic manifestations, including skin rash and edema
Allergic Purpura
Anaphylactoid Purpura
Associated with certain foods and drugs, cold, insect bites, and vaccinations.
Allergic Purpura
Anaphylactoid Purpura
Acute IgA-mediated disorder
Henoch-Schonlein Purpura
Generalized vasculitis involving the skin, joints, kidneys, GI tract, and, less commonly, the lungs.
Henoch-Schonlein Purpura
Generalized vasculitis involving the skin, joints,kidneys, GI tract, and, less commonly, the lungs.
Henoch-Schonlein Purpura
Frequently confused with ITP.
Henoch-Schönlein Purpura
Primarily a disease of children. (3-7 years of age)
Henoch-Schonlein Purpura
Twice as many boys are girls are affected.
Henoch-Schonlein Purpura
Clinical presentation:
○ Malaise, headache, fever, and rash.
Henoch-Schonlein Purpura
The skin lesions are urticarial and gradually become pinkish, then red, and finally hemorrhagic.
○ “Palpable purpura”
○ Most commonly found on the feet, elbows, knees, buttocks, and chest.
Henoch-Schonlein Purpura
Henoch-Schonlein Purpura
● Laboratory Findings:
○ Normal PLT count
○ Elevated WBC count
○ Elevated ESR
○ Normal Coagulation studies
○ Proteinuria and Hematuria
○ Anemia (only if hemorrhagic manifestation is severe)
Severe hemorrhagic manifestations as a result of a combination of hyperviscosity and platelet
dysfunction.
Dysproteinemia
Inhibits platelet aggregation, secretion, and
procoagulant activity.
Dysproteinemia
Coating of platelet membrane with paraprotein inhibits adhesion and activation receptor.
Dysproteinemia
Also inhibits assembly of clotting factors on the platelet surface.
Dysproteinemia
A disorder of women that presents with recurrent purpura on the lower extremities and resultant hemosiderin staining of the skin.
Waldenstrom Macroglobulinemia
● Is caused by production of cryoprecipitable serum proteins or protein complexes.
Cryoglobulinemia
Exposure to cold may cause purpura on the skin
of the extremities or face
Cryoglobulinemia
The purpura may cause blister or ulcerate.
Cryoglobulinemia
Autoimmune mechanisms
IgA Myeloma
IgG Myeloma
● Interact with platelet receptors.
● Interfere with platelet aggregation.
● Increases plasma viscosity.
IgA Myeloma
IgG Myeloma
refers to a misfolded, insoluble protein that accumulates in tissues and organs, forming deposits known
Amyloid protein
Resistant to normal protein degradation process.
Amyloidosis
Deposited extracellularly and may damage tissue.
Amyloidosis
Purpura, hemorrhage, and thrombosis maybe part of the clinical presentation.
Amyloidosis
Due to lack of collagen support for small blood vessels and loss of subcutaneous fats and elastic fibers
Solar purpura
More common in elderly men than women.
Solar purpura
Dark blotches are flattened and do not blanch with pressure. (Age Spots)
Solar purpura
The lesions are limited mostly to the extensor surfaces of the forearms and backs of the hands.
Solar purpura
Caused by a deficiency of vitamin C.
Scurvy
Causes defect in the synthesis of collagen in the walls of small blood vessels
Scurvy
May present with swelling, pain, or discoloration.
Scurvy
Gingival bleeding and hemarthrosis may also be
present.
Scurvy
Perifollicular hemorrhages with hyperkeratosis of the hair follicles and “corkscrew” hairs are characteristic.
Scurvy