Petechiae/Purpura

Question 1

Purpura definition

Answer 1

Non-blanchable red to purple lesions due to extravasaion of blood into skin/mucous membranes

Key is that these are NON-blanchable because the tissue cannot move…because extravasated red blood cells cannot move

Question 2

Nonpalpable vs. petechiae vs ecchymoses

Answer 2

Non-palpdable purpure is flat or macular

Petechiae are <3mm…ecchymoses are >5mm

Question 3

Source of nonpalpable purpura, petechia, eccynoses and necrotic ecchymoses

Answer 3

Bleeding into the skin without blood vessle inflammation due to a bleeding diorser or blood vessel fragility

Petechiae - thrombocytopenia

Ecchymoses - fragile blood vessels

Necrotic - DIC

Question 4

Palpable purpura source

Answer 4

Due to inflammatory damage to the blood vessel (vasculitis)

Lesions elevated due ot inflamation

Question 5

Appraoch to purpura

Answer 5

Sick or not sick…if not sick …then look at palable vs non

Question 6

Nonpalpable sick and palpable sick

Answer 6

Non - RMSF, spesis/DIC, minigococemia

Palp - vasculitis

Question 7

Not sick, nonpalb

Answer 7

Scurvye or senile purpura

Question 8

Scurvey etiology/epi

Answer 8

Vitmane C required for collagen synthesis…without it, fragiligty of skin

Loss of Vit C, dialysis, use of meds, smoking

MUst absorb Vitamin C…water soluble

Question 9

Scurvy pathology,

Answer 9

Needed to hydroxylation of proline on procollagen, allowing formation of HH bnding in triple helix of mature collagen…without Vit C, unable to form stbale helices…causes decreased collagen secretion from fibroblast and unstable collagen

Question 10

Scurvey signs and sx

Answer 10

Perifollicular purpura, large eccyhmoses on lower legs, IM and periosteal hemorrhage, heratotic plugging of hair follicles, hemorrhage gingivitis

Question 11

Senile purpura etiology, epidemiology, sings and sx, appearance and distribution

Answer 11

With age and sun damage, dermal tissue thins and increases fragility of BVs…epidermis thinned and dermis has reduced amounts of collagen replaced by abnormal fibers…vessels of dermis normal but supporting ittuse damaged

Over 50, steroid use, chronic sun exposure

Benign recuurent ecchymoses on extenosrs of forearms following minor trauam

Irregular macule shas 1-4 cm with well defined margins…no color change over time

Extensors of forearms

Question 12

RMSF Eiology
Appearance
Distribution
Asociated sx

Answer 12

NC, oklahoma, ark, tenn, mz…tick borne from rickettsia rickettsia…gram - intracellular coccobacillus…spring and early summer

Blanching erythematous rash with macules that becmes petechial

Begins on ankels and wrists and spreads to trunk…palsma and soles later

Fever, headache, nausea, and malaise…myalgia and arthralgia

Question 13

Sepsis etiology

Answer 13

Inflammatory response spills over to systemic symptoms

Endotoxin LPS of gram negative binds to LPS bdining protein..monos and macros recognize and activated…release inflam mediators that induce inflmaation, enodthelial damage, hypotension and organ dysfunction

Activate leukocysts and promote adhesion and damage…endothelial damage can leads to expression of tissue factor and trigger clotting cascade…this can trigger DIC

Question 14

DIC

Answer 14

Coagulation and fibrionlysis dysregulated with widesrpead clotting and resultant bleeding

Reelease of TF is key

Excess thrombin cleaves fibrinogen to fibrin which leaves fibrin clots…clots trap platelets…leads to ischemia

Clotting factors consumed and excess thrombin converts plasminogen to plasmin…results in fibrinolysis…brekadown results in fibrinogen split products which have anitcoagulatn properties and contribute to hemorrhage

Question 15

Signs and sx and appearance of spesis/DIC

Answer 15

Systemically ill…fever and schock

Stellate non-palpable purpura

Dark gray areas that will eventually slough

Central area nevrotic

Stellate shape classic for BV thrombosis and infarction

Question 16

Meningococcemia epi/etio

Answer 16

Neusseria meningitidies…gram - diploccoi…leading cause in children and young adults

Meningoccoal septicemia is a blood strwam infection resulting in damage to blood vessel

If occuring with DIC, then purpura fulminans

Question 17

Meningococcemia signs and sx, appearance, diagnosis, tx

Answer 17

Fever, headache, stiff neck, N/V, photophobia…if progression, then hypotension and schok

Early on there may be nonspecific rash…petechiae often develo…purpuric lesions with jagged edges progress to necrosis

Culture of blood and CSF

Empiric antibiotics…normally IV ceftriaxojone…may give usportive therapy with fluids

Question 18

Vasculitis etio/epui

Answer 18

Inflammation of BV by immune system

SMall vessels present with palpable purpura and medium sized with nodules and ulcers

Veell inflammation results in damage to vessel walls causing extravasation of RBCs into tissue

Lesions are elevation due to inflammation…purpiic because of leakage

Question 19

Vasculitis signs and sx, appearance, diagnosis

Answer 19

Constitutional sx, pain, other organs

Palpbale purpura with predileciton for lower extremities

Skin biopsy