Not a feature of postmortem staining

Not a feature of postmortem staining -
a) Occur immediate after death
b) Common in dependent part
c) Disappear with putrefaction
d) Margins are sharp
Correct Answer - A
Ans. is ‘a’ i.e., Occur immediate after death [Ref Reddy 30th/e
p.141,142]
Postmortem staining is an early sign (not immediate sign) of death.
It refers to discoloration of skin and internal organs after death due
to accumulation of fluid blood in toneless capillaries and small veins
of dependent part of the body.
It does not appear elevated above the surface but has sharply
defined (usually horizontal) margins.
It is an early sign of death. It starts at about 1 hour, becomes a
series of mottled patches within 1-3 hours and these pathces
increase in size to coalesce in about 3-6 hours. After 6-12 hours,
lividity is fully developed and fixed (unchangeable), i.e. primary
lividity. It ends when putrification sets in. Fixation of lividity is due to
stagnation of blood in distended capillaries and venules (not due to
coagulation of blood).