Aplastic Anaemia 

Aplastic anaemia is a condition in which production of red cells in the bone marrow is reduced. It involves failure to produce adequate red cells, white cells, and platelets. 

Etiology 

This can be classified as: 

1)  Idiopathic aplastic anaemia: This constitutes 50 per  cent of  the cases. Its cause is unknown. 

2)  Acquired (secondary) aplastic anaemia: This is due  to drug  toxicity or sensitisation, e.g. chloramphenicol, sulphonamides, Phenylbutazone, and antimitotic  drugs. 

3)  Aplastic anaemia associated with multiple congenital defects: This  is hereditary and accompanied by skeletal, eye, heart, kidney, genital and other pigment abnormalities.