No botheration. The probable cause is Sebaceous Cyst - which is nothing but swollen hair follicle. Skin injury
make the hair follicle (sac) to grow in size by a collection white material (a type of protein). When infected the white material turns very thick and sometimes foul smelling. Usually it is easily diagnosed by a center punctum. It is an ordinary tumor
arising from skin which can easily be removed by General Surgeon
under local anesthesia
. Recurrence is very rare.