Snakebite Clinical Presentation

Updated: May 15, 2017
  • Author: Brian J Daley, MD, MBA, FACS, FCCP, CNSC; Chief Editor: Joe Alcock, MD, MS  more...
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Presentation

History

History usually can be obtained from the patient. Most cases result from attempting to handle snakes, so the genus usually is known. Knowledge of indigenous fauna also is important.

The time elapsed since the bite is a necessary component of the history. This allows assessment of the temporal effects of the bite to determine if the process is confined locally or if systemic signs have developed.

Obtain a description of the snake or capture it, if possible, to determine its color, pattern, or the existence of a rattle.

Most snakes remain within 20 feet after biting a human.

Assess the timing of events and onset of symptoms. Inquire about the time the bite occurred and details about the onset of pain. Early and intense pain implies significant envenomation.

Local swelling, pain, and paresthesias may be present.

Systemic symptoms include nausea, syncope, and difficulty swallowing or breathing.

Determine history of prior exposure to antivenin or snakebite.

Determine history of allergies to medicines because antibiotics may be required.

Determine history of comorbid conditions (eg, cardiac, pulmonary, and renal disease) or medications (eg, aspirin, anticoagulants such as warfarin [Coumadin] or GPIIb/IIIa inhibitors, beta-blockers).

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Physical

Follow the established routine for a complete comprehensive examination. Keep in mind that acute patients still need to be stabilized (ie, treat airway compromise or shock). See Table 1 in Medical Care for the Snakebite Severity Scale.

Note the following important tips:

  • Vital signs: Initial stabilization is same as in any acute patient and includes airway, breathing, and circulation.
  • Fang marks or scratches: Determine the coral snakebite pattern by expressing blood from the suspected wound.
  • Local tissue destruction: Soft pitting edema generally develops over 6-12 hours but may start within 5 minutes; not bullae, streaking, erythema or discoloration, and contusions.
  • Systemic toxicity: Note hypotension; petechiae, epistaxis, and hemoptysis; and paresthesias and dysesthesias, which forewarn neuromuscular blockade and respiratory distress (more common with coral snakes).

Effects from a copperhead bite are shown in the images below.

Snakebite. Copperhead bite day 3; initial wounds t Snakebite. Copperhead bite day 3; initial wounds to finger.
Snakebite. Copperhead bite day 3; initial wounds t Snakebite. Copperhead bite day 3; initial wounds to finger.
Snakebite. Copperhead bite day 3; initial wounds t Snakebite. Copperhead bite day 3; initial wounds to finger.
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Causes

In the United States, more than 40% of victims put themselves in danger by either handling pets or attempting to capture reptiles in the wild. The popularity of keeping exotic species has increased the number of envenomations by nonnative species.

UTMCK data support this by reporting that 15 of 25 patients were bitten handling snakes; 2 of these were involved in religious ceremonies.

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