FORENSIC PATHOLOGY REVIEWS Volume 1 - Securimetric

6 Bohnert
2. EXTERNAL FINDINGS
2.1. General Aspects
Among the externally discernible changes, the dominant features are the
various stages of skin burns, the results of tissue shrinkage, and the consumption
by the fire. Destruction can be so extensive that the less experienced tend to
consider an autopsy pointless because, in their opinion, it will not produce any
findings anyway. But this opinion is definitely wrong: even in charred torsos
with general incineration, exposure of the body cavities, and partial amputation
of the extremities as a result of the fire, the organs of the thorax and abdomen
can usually still be assessed quite well. Moreover, sufficient amounts of body
fluids and tissue samples can be obtained for further investigations.
2.2. Burns
Skin burns are categorized into four degrees, with each degree characterizing
a certain depth of the skin lesion. The categories are: degree 1—
superficial burns, degree 2a—superficial partial-thickness burns associated
with necrosis of the upper layers of the epidermis, degree 2b—deep partialthickness
burns associated with necrosis of the entire thickness of the epidermis,
degree 3—full-thickness burns with necrosis involving the dermis
as well, and degree 4—charring in which the heat lesion reaches deeper
soft-tissue layers.
Skin burns are the result of temperature and duration of exposure: the
higher the temperature, the lower the duration of exposure necessary to achieve
a certain degree of burn. The lowest temperature considered necessary for
causing damage is an actual skin temperature of 44°C, although under this
condition no less than 6 hours are required to reach a second- to third-degree
burn (34–36). Between 44°C and 51°C, a rise in temperature by 1°C halves
the duration of exposure necessary to cause a certain degree of damage to the
skin. Above 51°C, the excess heat is no longer conducted away by convection
via the capillaries of the skin. The heat penetrates into the deeper layers of the
tissue. For the actual skin temperature the kind of transmitting of the heat to
the body is of major importance: the penetrating power of moist heat is considerably
higher than that of dry heat (34–37).
The usual staging of skin burns according to clinical symptoms is of
minor importance in the forensic evaluation of findings, because no conclusions
can be drawn from the degree of the burns to the intravital effects of the
heat. The question of whether skin burns occurred while the victim was still
alive is difficult to answer. Erythemas (first-degree burns) are characterized