484 Emergency Medicine
resolve spontaneously or progress to hypertension and cardiovascular failure.
Black widow spiders have a signature hourglass bright-red marking on the
underside of the abdomen. The Brown recluse spider typically has a violin-like
marking on their abdomen.
437.The answer is c.(Rosen, p 911.)This patient has ultraviolet keratitis,
also known as snow blindness.This is essentially a radiation burn when
an individual comes in close contact with an ultraviolet-ray—containing
light source.It may be caused by sun lamps, tanning booths, or high-alti-
tudeenvironments. Patients usually present about 6 to 10 hours postexpo-
sure complaining of eye pain, blepharospasm, tearing, photophobia, and
foreign body sensation. Physical examination reveals an injected eye with
decreased visual acuity. Corneal examination reveals punctuate lesions that
are clearly demarcated by a protective covering from the ultraviolet rays,
such as the inferior conjunctiva. Treatment consists of a short-acting cyclo-
plegic agent for pain management and broad-spectrum ophthalmologic
antibiotics. Treatment is guided to assist in the quick, natural healing
capacity of the cornea, in which the patient should feel better in a couple
of days.
Although a corneal abrasion (a)is possible, given the patients’ symp-
toms, his history and lack of trauma or contact lens use suggests otherwise.
Regardless, the treatment is the same. Iritis (b)usually is an injury of blunt
trauma, resulting in ciliary spasm. Patients complain of photophobia and
eye pain. Physical examination reveals ciliary flush, cells and flare in the
anterior chamber and a small, poorly dilating pupil. Corneal foreign bodies
(d)and corneal lacerations (e)are usually traumatic injuries in which the
patient can recall a specific event. Corneal foreign bodies can be visualized
upon physical examination using fluorescent dye and may present with an
abrasion or ulceration. Small corneal lacerations may be difficult to diagnose.
A positive Seidel test in which fluorescent dye streams from a corneal wound,
indicates leaking aqueous humor, can be diagnostic. This is an ophthalmologic
emergency that may warrant surgical repair.
438.The answer is a.(Rosen, pp 2035-2048.)This patient is recovering
from acute mountain sicknesswith no signs of CHF or pulmonary
edema. The first-line treatment is descent and oxygen supplementation,
which is already accomplished in this patient. Other treatment considerations
include hyperbaric oxygen therapy, which improves hypoxemia for all altitude
illnesses. As for medication regimens, acetazolamideis indicated even in