Thanks for sending your Query to us.
Such sudden redness
without too much of pain indicates a rupture of small blood vessel leading to haemorrhage.
This blood resolves on its own and does not requie any treatment.
All you have to check that you are not taking any form of aspirin
XXXXXXX increases the tendency of such bleeding.
In the begining some cold
compress prevents prevents excessive bleed.
This takes about 10 to 15 days for the blood to gradually resolve.
Please do get back to me in case of any further query in this regard.