Allergies, pre-existing conditions and antivenom

Allergies to antivenom components

Written by Dr. Spencer Greene and Dr. Nick Brandehoff

Allergies to pineapple, bromelain, papaya, papain, and similar substances, including latex, as well as allergies to sheep or horses, may increase your risk of an adverse reaction to antivenom. The potential risks and benefits must be weighed. There’s no absolute contraindication to antivenom.

Antivenom should not be withheld for an envenomation that warrants treatment. If you are at higher risk of having an adverse reaction, it may be prudent to pre-treat. Allergies and anaphylaxis can be treated. Venom-induced injuries cannot be fixed without antivenom.

Alpha-gal and antivenom

Written by Dr. Spencer Greene

I actually lectured on this for the American College of Medical Toxicology!

All antivenoms have alpha gal to some extent. We have two options when treating an AGS patient with antivenom. We can monitor really carefully and treat if/when signs and symptoms develop, or we can pre-medicate with antihistamines +/- steroids with epinephrine available. You never want to withhold antivenom when it is really necessary. We can treat an allergic reaction.

Pre-existing medical conditions

Per Dr. Brandehoff:

Each envenomation is unique. Any medical condition can increase the risk of complications in a snakebite. With that said, the assessment and treatment is the same. These are cases where a toxicologist experienced in snakebites should be consulted to guide treatment based on the nuanced clincial presentation.

If an evenomation requires antivenom, you treat with antivenom. There is no absolute contraindication.