Nonbite Exposures to Rattlesnakes: A Retrospective Review From a Statewide Poison Control System

To the Editor:

Although the majority of rattlesnake venom exposures involve bites, some cases that are referred to poison control centers concern nonbite exposures. We analyzed all nonbite exposures that were called into a statewide poison control system during a 4-year period. Calls made to the California Poison Control System from the years 2000 to 2003, inclusive, were retrospectively reviewed for rattlesnake exposures where the route of exposure was coded as something other than a bite. Miscoded cases (ie, cases where a bite actually occurred) were excluded. Patient route of exposure, symptoms, interventions, and outcome were recorded.

A total of 53 cases of nonbite exposures to rattlesnakes were identified. Patient ages ranged from 7 months to 64 years. The majority of exposures (62%) occurred in adult patients during killing, skinning, decapitation, or transfer of animals or parts. The predominant nonbite exposure route for rattlesnake venom was dermal (23 cases), followed by ocular (10 cases), oral (2 cases), and a combination of dermal and ocular (3 cases). Additionally, there were also a few calls regarding contact with other snake components, such as snake skin and rattles (10 calls), blood and secretions (5 calls), viscera (2 calls), and dried skeletal parts (1 call) (see Table).

Ten patients (19%) were evaluated in a health care facility; the remaining 43 (81%) were managed on site. Recorded interventions were irrigation and washing only. Only the 38 patients exposed to venom reported any symptoms. Transient irritation or tingling was noted in 3 of the 10 patients with ocular exposures and 6 of the 26 patients (23%) with dermal exposures. Of the 2 patients with oral exposures, 1 reported irritation.

Poison centers may be called about a variety of nonbite exposures to rattlesnakes. These data may help poison centers develop guidelines to address unusual exposures from rattlesnake parts and nonbite venom exposures. None of our patients developed any symptoms more severe than transient discomfort and did not require any interventions other than irrigation or washing, which is consistent with the few similar reports pub

Routes of exposure for nonbite exposures to rattlesnake venom and tissues

lished previously.^1,2 Our study supports published reports that suggest that ocular exposures from Crotaline venom does not appear to result in clinically significant symptoms, unlike ocular exposures from the spitting cobras (eg, Naja nigricollis). ³ It is unclear whether this difference is due to the intrinsic toxicity of the venom, the venom quantity involved, differences in snake behaviors, or timing and technique of decontamination. Although none of our patients developed significant local tissue effects, the occurrence of true envenomation from dead and even decapitated snakes’ fangs has been reported,^4,5 thus warranting a cautious approach in any handling of killed rattlesnakes.

On the basis of this case series, nonbite exposures to rattlesnakes can be managed at home with basic decontamination, with referral to a health care facility reserved only for severe or persistent symptoms.