Why does my wife have blue patches on her skin?

Q: My wife gets blue / purple patches on her body. Sometimes she gets them when her skin gets rubbed against a table / chair while cleaning the house; at other times, it is without any apparent reason. The smear goes away with time and it does not hurt. What could be the reason? Are there any precautions that she should take? She is taking medicine for BP and thyroid.

A:A. Blue patches on the skin are due to bleeding under the skin. It could be due to pressure on skin capillaries or due to bleeding problem because of low platelets. In your case since it has been for many years, chances of a major underlying cause are remote. You will need to keep note of the following: bleeding time (BT); clotting time (CT) and platelet count. If these are normal, take vitamin C tablet 1000 mg daily.