Petechial Hemorrhages in Suicide by Hanging: Possible Contributing Variables in Petechial Development.

Hemorrhagic petechiae in the conjunctiva and the skin have been related to type of suspension and body height of the victims of hangings. In 265 cases of hanging, we retrospectively examined whether petechiae relate to type of suspension, body weight and height, body mass index (BMI), age, sex, type and thickness of the ligature, and blood alcohol content. The type of suspension was divided into completely suspended, incompletely suspended, and found with feet touching the ground. There was no significant difference in the frequency of petechiae between the feet touching the ground and complete suspension, and they were therefore considered as one group (complete suspensions). Incomplete suspensions had more (58.7%) petechiae than the complete suspension group (30.2%). Statistical analysis showed that incomplete suspension was significantly stronger related to the development of petechiae than complete suspension. Body mass index was the only variable able to add information to the type of suspension. In victims of incomplete hangings, high BMI yielded 2.58 times higher probability of developing petechiae than low BMI. These findings suggest that body size may contribute to the development of petechiae in hangings.