• Clinical science

Environmental pathology

Summary

Exposure to cold, heat, and electrical currents produces characteristic changes in and on the body. Evaluation of these findings allows conclusions to be drawn about the type of damage and when it may have occurred. In the case of exposure to extreme heat, for instance, ante mortem vital signs may be distinguished from post mortem changes. These findings shed light on whether the individual was alive at the time of the fire or already deceased. A typical characteristic of death caused by hypothermia is hemorrhagic necrosis of the gastric mucosa (Wischnewski spots). Death caused by an electric shock may be manifested differently based on the current, voltage, and level of resistance. While a high level of resistance is associated with burns and electrical marks, a lack of characteristic findings is typical in low resistance shock.

Heat

For tissue damage caused by burns see burns.

Cold

For tissue damage caused by hypothermia see hypothermia and frostbite

Electrical injury

Lightning strike

  • Fatal in up to 30% of cases; cardiac arrest due to arrhythmias is the most common cause of death
  • 70% of survivors have permanent damage (e.g., chronic pain syndromes).
  • Lightning strikes can be demonstrated as a cause of death based on the following:
    • Lichtenberg figure: branching (fern‑like) patterns on the skin
    • Large burns or groups of small burns that appear similar to gunshot wounds
    • Scorched hair on the scalp
    • Findings on clothing
      • Grouped holes in the individual's clothes
      • Laceration of leather and shoe soles
      • Traces of melting on the body from metal (belt buckles, wrist watches)
    • Metalization of the skin: At the point of electrical contact, there is evidence of volatilization and deposition on the skin from metal that was located at the time on the body (evidence via histochemistry or atomic absorption spectrometry).

[1][2]

Snake and spider bites

Snake bites

Spider bites

  • Rare medical events; only a few species of spider are harmful
  • Most commonly result in a solitary papule, pustule, or wheal
  • Systemic manifestations (e.g., respiratory distress, pulmonary edema, hypertension) occur if sufficient amounts of venom enter the circulation.

For management of animal bites, see bite wounds.

[3][4][5]