[Campbell Biology P.1019] A snake handler is bitten by a venomous snake and treated with anti... | Practice Question

A snake handler is bitten by a venomous snake and treated with antivenin. If the same handler is bitten again by the same species and receives the same antivenin, why might a harmful side effect occur during the second treatment, even if the antivenin effectively neutralizes the venom?

  • A: The antivenin becomes less potent after the first exposure, leading to a weaker therapeutic effect.
  • B: The snake handler's immune system may have developed an allergic (hypersensitive) response to components of the antivenin from the first exposure.
  • C: The venom from the second bite is likely stronger, overwhelming the antivenin's capacity.
  • D: Antivenin always causes kidney malfunction, and the effect is cumulative with repeated doses.

Explanation

Antivenin is typically produced in animals e.g., horses and contains foreign proteins. Upon the first exposure, the snake handler's immune system may recognize these foreign proteins as antigens and produce antibodies, including IgE. A subsequent exposure to the same antivenin can then trigger an IgE-mediated allergic reaction hypersensitivity because the immune system is now 'sensitized' to the antivenin components, leading to harmful side effects like those seen in hay fever or more severe reactions.