Polycythemia

Question 1

Define polycythemia

Answer 1

Polycythemia means-increased number of RBC
polycythemia vera is a myeloproliferative neoplasm –clonal disorder with classical erythroctyosis, and thrombocytosis

Secondary Polycythemia (non vera) can also result from chronic hypoxia (COPD) or genetics
or tumours making erythropoietic

Question 2

Epidiemology and risk factors of polycythemia

Answer 2

Polycythemia vera is a neoplasm of RBC progenitors–95% have a JAK2 mutation. a driver of PV but unclear if actually what starts it
Secondary causes are often chronic tissue hypoxia causing physiological increase of erythropoetin, or renal tumours producing erythropoietin

Risk factors:
COPD/Smoking
Living in altitude (long term)

PV-age over 70
median age 61
Budd-chiari syndrome
Fhx

Question 3

Epidiemology of polycythemia

Answer 3

PV-about 2 in 100000 per year over 55
much higher over 70-24 in 100 000
10% are under 40

2ndary-unclear, but COPDis common

Question 4

Signs and Sx of polycythemia

Answer 4

Consider when a patient presents with thrombosis–inital PC in nearly always arterial or venous thrombosis

Other-headaches, generalised weakness, splenomegaly, pruritus, plethora, or erythromyelgia (painful, red extremities, palm, heels)
Facial redness is also common

splenomegaly

PV tends to be a lot more symptomatic than secondary polycythemia
secondary can be asymptote and just incidental from FBC-especialy if caused by COPD

Question 5

Investigations of polycythemia

Answer 5

FBC-HIGH RBC
High heamatocrit
MCV-low, IDA picture

in PV-leukocytosis, thrombocytosis
LFT-fine
JAK2 mutations-present

oxygen saturation-secondary causes
serum erythropoietin -raised in 2ndary