Thrombocytosis

Plts > 500
1ry vs 2ry

1ry
'Essential thrombocythaemia'
Myeloproliferative D/O
Dx of exclusion
25% prolonged BT with abn plt function
25% vascular thromboses (thrombotic and bleeding probs)

Tx
Cytotoxic agents = decreases plt count
(hydroxyurea/radioactive 32P)

2ry
Rarely plt count >1000

Chronic bleeding
Low Fe
Trauma
Inflammation - neoplasm/chronic infection (TB)/Chronic collagen disorders (RA)