Harrison’s Manual of Medicine 19th edition provides 600+ internal medicine topics in a rapid-access format. Download Harrison’s App to iPhone, iPad, and Android smartphone and tablet. Explore these free sample topics:
-- The first section of this topic is shown below --
- Epidemiology: Worldwide, 1.2–5.5 million snakebites are sustained each year, with 421,000–1,841,000 envenomations and 20,000–94,000 deaths.
- Bite rates are highest in temperate and tropical climates where populations subsist by manual agriculture and fishing.
- Differentiation of venomous from nonvenomous snake species can be difficult; color pattern is notoriously misleading.
- Clinical features: Snake venoms are complex mixtures of enzymes and other substances that promote vascular leaking, cause tissue necrosis, affect the coagulation cascade, and impair organ function.
- Specific presentations differ somewhat with the particular snake species.
- Systemic symptoms may include hypotension, pulmonary edema, hemorrhage, altered mental status, or paralysis (including muscles of respiration).
- Prognosis: The overall mortality rate for venomous snakebite is <1% among U.S. victims who receive antivenom; the incidence of permanent functional loss in a bitten extremity is substantial.