Tuesday, January 22, 2008

Vol 2:3 Answer

The Question

The answer is c

This patient sustained an injury from a venomous marine animal. Approximately 50,000 such incidents occur yearly. Marine animals may be divided into two classes: stingers and nematocysts. Stingers include sea urchins, stingrays, catfish, cone shells, and starfish. Radiographs may be useful in delineating the calciferous material deposited in the skin for removal. Nematocysts are much more prevalent and account for the majority of envenomations and most likely account for this patient’s distress. This class includes jellyfish, fire corals, Portuguese man-o-war, and anemones. These creatures have spring-loaded venomous glands that discharge upon mechanical or chemical stimulation. The number of nematocysts on a tentacle can number in the thousands. These stinging cells can remain activated after weeks of the animal being beached. The venom contains various peptides and enzymes that may cause progression of symptoms including nausea, muscle cramps, dyspnea, angioedema, and anaphylaxis. The preferred treatment is vinegar, which deactivates the nematocyst. In cases where medical attention cannot be sought in a timely manner, urine has been shown to be just as efficacious. An attempt may be made to shave off nematocysts after proper analgesia. Patient should be given tetanus prophylaxis and anti-histamines as needed.

(a) Fresh water activates the nematocyst and should be avoided. (b, d, and e) Vegetable oil, toothpaste, and household window cleaners should also be avoided as they might cause further irritation and pain.

Don't forget to give this week's VizD a try.

quizzER is a weekly contest consisting of a question selected from various areas of emergency medicine that are central to the education of medical students and residents in training. For more information please refer to the following link.

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