Biology Reference
In-Depth Information
be withheld. However, this very concerning consideration has not been well-docu-
mented and is less likely than the opposite, thoroughly documented scenario.
Although almost wholly relevant to only bites by captive specimens in private col-
lections, an additional consideration is the recognition of genetic variants or different
color phases of some colubroid species. There is a wide array of genetically selected
variants (“sunset,” albino, leucistic, melanistic, etc.) of selected snakes including elapid
species (e.g., monocellate, or monocled cobra,
Naja kaouthia
), crotaline viperids (e.g.,
western diamondback rattlesnake,
Crotalus atrox
; eastern diamondback rattlesnake,
C. adamanteus
;
Plate 4.91A
), and non-front-fanged colubroids such as the western
hognose snake (
H. nasicus
;
Plate 4.91B-F
). Therefore, victims of bites from venomous
or nonvenomous snakes may present with a snake specimen that is not readily recog-
nizable to those unfamiliar with genetic variants. The treating clinician must remain
aware of this possibility and, if unfamiliar with these variants, seek well-informed con-
sultation for accurate identification of the specimen.
Conclusions and Recommendations
When determining the medical importance of little-known ophidian species, docu-
mented and verified identification is an essential and fundamental necessity. Using
stringent safety precautions, and whenever possible, any specimen involved in a bite
should be procured and brought to a recognized institution for confirmation of identity.
This could allow precise documentation of the specimen, confirming attribution of the
case and aiding future study. If the specimen is not captured or sacrificed, photographs
(even cell phone photos) can sometimes establish the identification.
With the exception of a handful of toxinologists and specifically trained medi-
cal professionals, most clinicians should not attempt to identify specimens brought
by patients. This may include phase/pattern variants of common species that are
selectively bred for the commercial trade. Unfortunately, such identifications by
medical staff are frequently incorrect for snakes (Ariaratnam et al., 2009; Viravan
et al., 1992), and for spiders assumed to be responsible for skin lesions incorrectly
identified as necrotic araenism (Vetter, 2009). In a study examining the ability of a
cross-section of Australians to identify venomous and nonvenomous snakes, only
approximately 25% of medical students and physicians in the study could accurately
identify a given ophidian species (Morrison et al., 1983). Identification must be veri-
fied by a herpetologist or appropriately trained toxinologist.
4.5.1.2 Lack of Qualified Medical Assessment/Review
One of the most common flaws in reports of purportedly significant medically signifi-
cant non-front-fanged colubroid bites is lack of formal medical review. Any case of
snakebite with medical effects that are perceived as significant requires evaluation by a
medically qualified professional. This is important for the patient's care based on a care-
fully collected and analyzed history. This includes verification of identity of the snake
(see previous section); consideration of sympatric alternative species potentially respon-
sible for the bite if identity cannot be established; review of the medical history, aller-
gies, and any medications that might influence or account for the presentation; and, if
