chemical burns

 

Corrosive substance warning label

Source: Wikipedia

 

The severity of chemical burns relates to:

  • the chemical itself
  • it’s concentration
  • the amount and duration of contact

Acids produce coagulative necrosis, and the eschar formed helps to prevent further penetration. However, alkalis cause liquefaction and the penetration of the chemical burn is deeper.

Other chemicals such as hydrocarbons may produce damage by their organic solvent actions. (For a review of the use of chemicals in assaults, see Mannan et al (2007)).                                

Treatment of chemical burns includes the irrigation with water to remove the agent, and there are specific treatments available for others:

 

(Greaves et al 2001 pp. 212-213, Wardrope et al 1992 p.187, Britto et al 1999 p.112, US Naval Flight Surgeon Handbook 1998).

 

chemical burns in literature

 

The Sisters Brothers. DeWitt P 2011

Buy it here ...

 

Set in 1851, in the Ameican 'wild west', Charlie and Eli Sisters - killers for hire - travel to San Francisco in search of Hermann Kermit Warm, the inventor of a chemical that can create a 'River of Light'; they have been hired by the Commodore to kill Warm, and are due to meet their colleague - Henry Morris, a spy also paid by the Commodore - prior to completing their task.

On their arrival in San Francisco, however, they find that Morris and Warm have taken off into the woods close-by; the Sisters Brothers follow, and discover that the 'River of Light' refers to the unmasking of hidden gold fragments in the rivers worked by prospectors in the 'gold rush'. Warm and Morris have successfully used their chemical, but its use has had unexpected consequences. It is caustic, and has burned their arms and legs from contact with the solution in the water.

The would-be assasins decide to koin the two prospectors, but see the chemical burns develop: at first they are represented by purple-stained skin that itches, followed by darkening of the skin and blister formation. The flesh was 'agitated and raw'. Warm 'fairly shredded his own flesh with his fingernails"'. The extent of chemical burn spread up to the thighs, and the blisters filled with brownish liquid.

Charlie accidentally spills undiluted solution on his 'shooting hand', which causes immediate pain and 'blooming blisters accross his knuckles', which spread up to his wrist.

I could actually see the blisters rising and falling, as though they were breathing, the way a bullfrog takes air over its throat.

Soon his purple fingers became swollen, and 'threatened to burst they were so swelled up'. His flesh came away, and began to rot, requiring him to have his hand amputated.

electrical burns

 

Source: Gloucester City Council

 

 Electrical burns can be usefully divided into;

  • Flash burns – typically superficial
  • Contact burns – may be negligible surface burning but deeper tissue damage due to the conduction of electricity through tissue plains. These burns can be further divided into high tension or voltage and low tension/ voltage burns.

Electrical conduction through tissues causes damage due to the conversion of electrical energy to thermal energy, the amount of which is dependant upon tissue resistance and the potential difference across it.

Local injury is seen at the points of current entrance and exit (often the hands and the feet, where the body has been ‘earthed’ or grounded). In the case of high voltage injuries the burn may be caused by the conversion of electrical to thermal energy at the air interface adjacent to the body (Cooper 2003 p.191).

 

Electrical burn to the foot

Source: Dr Ken Harrison, Careflight

 

The passage of current through the body may also induce cardiac arrhythmias, hence the need to admit and observe all victims of electrical injury (Britto et al 1999 pp.112-113).

Low voltage/ tension burns are caused by domestic and light industrial supplies of 240V and 415V respectively. Contact skin burns are seen at both entrance and exit points, and should be closely looked for. Full thickness burns with deeper structure involvement may be seen ( Greaves et al 2001 p.214, Barret and Herndon 2001 pp. 14-16).

High voltage/ tension burns may be associated with massive tissue destruction at entry and exit points leading to muscle contractures requiring fasciotomies and possibly amputations. There can also be secondary ignition of clothing resulting in extensive cutaneous burns of a lesser degree.

 

Current

Thermal energy generated is proportional to the square of the current, the resistance and the duration of exposure (Joules Law). As the current is increased there is the sensation of tingling (<0.5 mA), pain (5 mA), involuntary muscle contraction/ hand spasm etc (10 - 16 mA), loss of consciousness (40 mA), and death (50 - 80 mA).

Voltage

Skin provides resistance to current flow, causing electrical energy conversion to thermal energy. The greater the thickness of keratin the greater the resistance. Sweating however reduces resistance.

Time

1st degree burns may occur with low voltage contact of a few seconds, whilst the longer the contact, the more severe the burn and the greater the risk of arrhythmias developing

Type of current

AC is more dangerous than DC (at the same voltage)

Route of the current

Passage of current through the chest is associated with an increased mortality (arrhythmias) compared with passage through the limbs

  Summary of the factors determining electrical burn severity

 

Low voltage electrical injuries are typically shallow craters with blistering (often surrounded by a rim of hyperaemia). Prolonged contact can result in higher degrees of injury.

At higher voltages, more extensive burn wounds are seen, and often no contact is required due to the phenomenon of ‘arcing’. Temperatures can reach 2500°C and this causes keratin to melt, producing a brown nodule (Cooper 2003 p.193, Knight 1999 p.322, Family Practice Notebook 2003).

Severe ‘flashover’ burns can also result from high voltage sources.

 

 

 

lichtenberg figures

 

Lightening strikes can characteristically give rise to a patterned surface burn, resembling a feather or a fern ('Lichtenberg figure'). However, they are frequently absent, and so collateral evidence is often required when diagnosing this type of injury.

 

Lichtenberg figure generated in acrylic using a particle generator @ Stoneridge Engineering

Read more about how these are formed here...

 

Watch Todd Johnson create a Lichtenberg figure ...

Lichtenberg figures can also be seen on the skin surface, as the following photographs illustrate nicely ...

Source: impactednurse.com via Geardiary

These were caused when a 24-year-old man, Winston, was struck by lightening.

references

  • Barret J.P., Herndon D.N. (Ed)(2001), ‘Colour Atlas of Burn Care’, W.B. Saunders
  • Britto J.A., Moganasundram S., Phipps A.R. (1999), ‘Thermal, chemical and explosive injuries’, Chapter 10 in ‘Trauma : A Scientific Basis for Care’, Alpar E.K., Gosling P. (Ed) Arnold Publishing
  • Cherington M, Olson S, Yarnell PR (2003), 'Lightening and Lichtenberg figures', Injury 34:267-271
  • Cooper P.N. (2003), ‘Injuries and death caused by heat and electricity’, Chapter 14 in ‘Forensic Medicine: Clinical and Pathological Aspects’, Payne-James J.J., Busuttil A., Smock W. (Ed) 2003 Greenwich Medical Media
  • Family Practice Notebook (2003), ‘Electrical Injury/ Burns’, (http://www.fpnotebook.com/ER35.htm)
  • Greaves I., Porter K.M., Ryan J.M. (2001), ‘Trauma Care Manual’, Arnold Publishing
  • Knight B. (1999), ‘Forensic Pathology’, 2nd Ed Arnold Publishing
  • Mannan A, Ghani S, Clarke A, Butler EM (2007), 'Cases of chemical assault worldwide: A literature Review', Burns 33:149-154
  • US Naval Flight Surgeon Handbook (1998)(2nd Ed), ‘Burn Management’
  • Wardrope J., Smith J.A.R. (1992), ‘The management of Wounds and Burns’, Oxford University Press

 

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