History
In some cases, it may be helpful to know where the bite occurred (geographically) and whether venom A populations are known to occur in the area. [12] Findings may include the following:
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Pain around the bite site
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Redness around the bite site
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Swelling (which may be less with Venom A Mojave rattlesnakes)
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Nausea, vomiting, or diarrhea
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Difficulty breathing
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Chest pain
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Weakness
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Paresthesias
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Syncope, near syncope
Physical Examination
Findings may include the following:
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Edema and erythema (Generally, local tissue effects are much less pronounced than typically observed after rattlesnake envenomation.)
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Tenderness surrounding bite site
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Tachycardia
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Hypotension/shock
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Myokymia (muscle movement, fasciculations)
Neurologic effects include the following:
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Cranial nerve palsies
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Ptosis
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Diplopia
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Dysphagia
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Dysphonia
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Motor weakness (severe, generalized)
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Respiratory paralysis
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Lethargy
Complications
Complications can include rhabdomyolysis, infection, respiratory difficulty, and death (rare).
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Mojave rattlesnake (Crotalus scutulatus). Note the diamond pattern fades into bands along the caudal third of the back and the white tail rings are wider than the black. Photo by Sean Bush, MD.
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This is the typical appearance of a southern California Mojave rattlesnake bite site. Photo by Sean Bush, MD.
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Mojave rattlesnake (Crotalus scutulatus). Photo by Sean Bush, MD.
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A red diamond rattlesnake (Crotalus ruber). The postocular light stripe extends above the angle of the mouth in Mojave rattlesnakes. Photo by Sean Bush, MD.
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This is a juvenile Mojave rattlesnake (postmortem). Note that the diamondback pattern fades into bands along the latter part of the snake's dorsum. Photo by Sean Bush, MD.
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A western diamondback rattlesnake (Crotalus atrox). Photo by Sean Bush, MD.