Environmental Exposures Answers 483these cases, as it has been proven as the most effective means of lowering
the virulence of the organism and should be initiated quickly. For immu-
nizing against the rabies virus, it is important to give the immunoglobulin
in addition to the cell vaccine.As much of the initial dose should be infil-
trated around the wound site and then be given intramuscularly. Pregnancy
is not a contraindication to giving the vaccine. All patients should be mon-
itored for an antibody response. In the United States, the predominant threat
to humans is bats,which most commonly carry the virus. This should be con-
sidered in individuals who are cave spelunkers and present with hydrophobia
and neurologic symptoms. Small rodents (squirrels, rats, chipmunks) and
lagomorphs are herbivores and do not carry the virus.
(a)Reporting the incident to local health officials is also warranted,
but may be done later. Suturing the sustained lacerations in these types of
injuries is controversial, but should never be tight (c).Head and neck lacer-
ations may be sutured for cosmetic reasons. Given the adequate blood supply
to these areas, infection rates are low. Antihistamines (d)are not usually indi-
cated in cases of dog bites. Irrigation of the wound with Betadine solution
(e)should never be performed as it causes further maceration of the skin
edges and tissue necrosis.
436.The answer is c.(Rosen, pp 795-796.)This patient’s necrotic lesionand
travel to the south-central statesis classic for a brown recluse spider bite.
Theseinjuries may present with systemic symptoms of fever, chills, myalgias,
hemolysis, petechiae and eventually seizure, renal failure, and death. The brown
recluse spider can be distinguished by its violin-shaped cephalothorax.
Its venom contains hemolytic enzymes and substances that cause vasocon-
striction. Initial lesions may appear targetoid, as blood supply to the central
area is diminished and becomes necrotic. Lesions have been shown to cause
significant scarring and infection. Initial treatment should include the ABCs,
wound care, analgesia, and tetanus prophylaxis. Patients may be observed
in the ED for a period of 6 hours to see if envenomation occurred. Antibiotics
may become warranted if infection ensues. Loxosceles reclusa antivenin is
manufactured in Brazil, but is not currently available in the United States.
Although these bites may cause a coagulopathy, a DVT (a)and throm-
bocytopenia(e)are not the underlying causes but rather a manifestation of
envenomation. Scorpion stings (b)are not so subtle. Patients feel immediate
localized pain followed by neurologic symptoms that may include salivation,
fasciculations, and blurred vision. The venom of Black widow spiders (d)causes
pseudoperitoneal symptoms because of painful muscle spasm. Spasms may