The<unk><unk>  is caused by firm stroking of the skin with a pointed object. but some time at caused by capillary vasodilation. The<unk>  is particularly sensitive in people with dermatographia urticaria. Some form of dermatographia is present in around 5% of the population.
Triple response of Lewis
Junior blood group system
Indian blood group system
Vel blood group
Augustine blood group system
P1PK blood group system
Rh blood group system
Hh blood group