Correspondence

Direction of a Lightning Strike

N Engl J Med 1994; 331:953-954October 6, 1994

Article

To the Editor:

The Image in Clinical Medicine entitled “Struck by Lightning” (May 26 issue)1 was interesting and beautifully presented. However, unless there is a recognized method of distinguishing the entrance and exit wounds caused by lightning, we believe the figure legend misleads the reader. The legend describes the lightning as entering the victim's body by the neck and exiting by her leg. Typically, lightning travels upward, not downward. During thunderstorms an excess negative charge of electrons accumulates in clouds. The earth below is positively charged. When the electromagnetic attraction between the cloud and the earth becomes great enough, electrons stream downward toward the positively charged earth. When this negatively charged leader nears the earth, a positively charged streamer ascends from the earth to meet it. When the descending leader meets the ascending streamer, an intense wave of positive charge, the lightning stroke, travels upward to the cloud. An excellent diagram and simple explanation of this can be found elsewhere2.

Denis L. Bourke, M.D.
Charles M. Harrison, M.D.
Juraj Sprung, M.D., Ph.D.
Veterans Affairs Medical Center, Baltimore, MD 21201-1566

2 References

1. 1

   Zehender M. Struck by lightning. N Engl J Med 1994;330:1492-1492
   Full Text | Web of Science | Medline

2. 2

   Williams J. The weather book. New York: Random House, 1992:111-29.
   

Author/Editor Response

The authors reply:

To the Editor: The description of the physical phenomenon of the discharge of lightning as given by Bourke et al. is correct as far as negatively charged lightning is concerned. In the case of a positive strike, the direction of the lightning will be opposite.

In the case of a negative strike, the partial lightning current through a person next to a tree goes from the leg to the neck, according to the physical definition. Because the polarity of the lightning strike is usually not known, people say colloquially that a partial lightning current “jumps” from the tree to the person in an arc, entering at the neck and leaving the body at the leg1.

In some patients, the orientation of the transient, fernlike, superficial skin markings2 may be helpful in defining the direction of the current better. In our patient3 these were oriented downward.

Manfred Zehender, M.D.
Universitatsklinik Freiburg, 79106 Freiburg, Germany

J. Wiesinger, Ph.D.
Universitat der Bundeswehr Munchen, 85579 Munich, Germany

3 References

1. 1

   Uman MA. The lightning discharge. International geophysics series. Vol. 39. Orlando, Fla.: Academic Press, 1987.
   

2. 2

   Bartholome CW, Jacoby WD, Ramchand SC. Cutaneous manifestations of lightning injury. Arch Dermatol 1975;111:1466-1468
   CrossRef | Web of Science | Medline

3. 3

   Zehender M. Struck by lightning. N Engl J Med 1994;330:1492-1492
   Full Text | Web of Science | Medline

Citing Articles (2)

Citing Articles

1. 1

   Jit-Kheng Lim, Eng-Hin Lee, Rethy Chhem. (2001) Journal of Pediatric Orthopedics 21:5, 608-612
   CrossRef

2. 2

   Jit-Kheng Lim, Eng-Hin Lee, Rethy Keith Chhem. (2001) Physeal Injury in a Lightning Strike Survivor. Journal of Pediatric Orthopaedics 21:5, 608-612
   CrossRef