ENVENOMATIONS - Medicine for Mountaineering and Other Wilderness Activities - page 496

The Mojave rattlesnake is small but has very potent venom with a high concentration
of neurotoxins. The effects of envenomation by this species tend to be delayed, may not
become fully apparent until twelve hours after the bite, and may be much more severe than
indicated by the initial reaction.
Diagnosis of Envenomation
Althoughidentifying thespecies ofsnakeinflicting abite isdesirable, itisnotessential.
In the United States catching or killing the snake is not advisable because the risks are
greaterthanthebenefits.Insomeareasoftheworld,broad-spectrumantiserumisnotavail-
able (for some species it is not effective), and specific antiserum must be administered. If
the snake cannot be precisely identified, specific therapy may be impossible.
Inspectingthebiteoccasionally helpsindeterminingthatthesnakeisvenomous.Typic-
ally the fangs of a pit viper produce two small puncture marks, which are a reliable indica-
tionthatthesnakewasamemberofthisfamily.However,characteristicfangmarksaredis-
tinctly uncommon. The target is usually moving, and the snake's strike is rarely accurate.
Only one fang may strike, or the fangs may only graze or scratch the skin. The snake may
be missing a fang, and occasional snakes have three or even four fangs. The fang marks
may be hidden among the marks from the other teeth if the snake has embedded its fangs
so deeply that the other teeth have also penetrated the skin. Although only the fangs have
entered the skin, a U-shaped row of teeth marks from the bottom jaw may be present.
Eventhoughanattackingsnakecanbepositivelyidentifiedasvenomous,theindividual
ithasbitten doesnotrequirespecific treatment unlessenvenomation hasoccurred.Venom-
ous snakes attack humans in sheer terror, not for food. Sometimes snakes strike without
opening their mouths or extending their fangs. Occasionally venom is only sprayed on the
surface of the skin or clothing. Even when the fangs pierce the skin, no venom or only a
verysmallquantityisinjectedinapproximately25percentofthebitesbyvenomoussnakes
occurringintheUnitedStates. Reportedly,forkingcobraandseasnakebitestheincidence
of nonenvenomation is about 80 percent, but reliable data are probably not available.
Iftheindividualhasbeenbittenbutnotenvenomated,thebiteshouldbetreatedlikeany
other animal bite to reduce the risk of infection. It must be thoroughly cleaned. Since the
woundisapuncturewound,bleedingshouldbeencouragedandtetanusprophylaxisshould
be administered.
Crotalid Envenomation
The reaction following the bite of a crotalid (pit viper) is one of the best indications
that the snake was venomous and is the only indication that envenomation has occurred
and treatment may be needed. This reaction begins within minutes after the bite, typically
is severe following an eastern diamondback rattlesnake bite, but may be less marked after