This form of discoloration is mostly seen in accident cases, where death was due to mechanical causes.
In ecchymosis the blood capillaries being ruptured, the blood permeates the bruised tissues surrounding the ruptured vessels and thus gives the characteristic color of venous blood. There seems to be no positive treatment, but in some cases it can be remedied to some degree by a hypodermic injection of a good bleacher, and then massaging the part with a strong bleaching solution. Spots of this kind can sometimes be covered with flesh tints.
It is often important to determine whether violence has been inflicted on a body before death. In regard to this point, we must remember, first, that blows and falls of sufficient violence to fracture bones and rupture the viscera may leave no marks on the skin, even though the person has survived for several days; and, second, that there are postmortem appearances which simulate antemortem bruises. A severe contusion during life may present, at first, no mark or only a general redness. After a short time the injured part becomes swollen and of a red color, this color may be succeeded by a dark blue, and this in turn fade into a greenish yellow or yellow; these later appearances are due to an escape of blood from the vessels and to a subsequent decomposition of the hemoglobin. If, therefore, we cut into such an ecchymosis after death, we find extravasated blood or the coloring matter of the blood, in the form of pigment granules, free in the tissues. Postmortem discolorations, on the other hand, although their external appearance may resemble that of antemortem ecchymosis, are not formed by an extravasation of blood, but by a circumscribed congestion of the vessels or by an escape of blood stained serum. If you cut into such discolorations, therefore, we find no blood outside the vessels. Care should be taken not to mistake the lesions of hemorrhagic infection for traumatic ecchymosis.
Blows on the skin of a body which has been dead for not more than two hours may produce true ecchymosis with extravasation of blood, such as can be distinguished with great difficulty or not at all from those formed during life. If putrefactive changes be present, the difficulty of distinguishing between antemortem and postmortem bruises is greatly enhanced.
Hanging and strangulation are attended with the formation of marks on the neck which are described in works on forensic medicine. These marks must not be confounded with the natural creases of the skin of the neck. Many adults during life have creases of the skin of the neck, one or more in number, running downward from the ear under the chin or encircling the neck. After death these creases may be much more evident than during life, and may be rendered more decided by the position of the head, or if the body be frozen. They usually persist until the skin putrefies.
(f)
Wounds.
—The embalmer should notice the situation, extent and the direction of a wound, the condition of the edges, and the surrounding tissues. If it be a deep, penetrating wound, its course and extent should be ascertained by careful dissection rather than by the use of a probe.
If the edges of a wound be inflamed and suppurating, or beginning to heal, it must have been inflicted some time before death. In a wound inflicted a short time before death the edges are usually everted; there may be more or less extravasation of blood into the surrounding tissues, and the vessels contain coagulated blood; but sometimes none of these changes occur. The chief characteristics of a wound inflicted after death are absence of a considerable amount of bleeding, non-retraction of edges, and the absence of extravasation of blood into the tissues. But a wound inflicted within two hours after death may resemble very closely one received during life. In general, unless a wound is old enough for the edges to present inflammatory changes, the embalmer must be very careful in asserting its antemortem or postmortem character.
(g)