Smallpox (variola major). Worldwide eradi-
cation of smallpox was achieved in 1977; the
United States and Russia have the only known
storage sites of the virus. The virus is consid-
ered a potential agent for biological warfare.
Initial signs and symptoms include high fever,
malaise, prostration, severe headache, back-
ache, and abdominal pain. A maculopapular
rash develops on the oral mucosa, pharynx,
face, and forearms and then spreads to the
trunk and legs. Within 2 days, the rash becomes
vesicular and later pustular. The lesions develop
at the same time, appear identical, and are
more prominent on the face and extremities.
The pustules are round, firm, and deeply em-
bedded in the skin. After 8 to 9 days, the pus-
tules form a crust, which later separates from
the skin, leaving a pitted scar. Death may result
from encephalitis, extensive bleeding, or sec-
ondary infection.
◆ Spinal neoplasm (benign). Spinal neo-
plasm typically causes severe localized back
pain and scoliosis.
◆ Spinal stenosis. Resembling a ruptured in-
tervertebral disk, spinal stenosis produces back
pain with or without sciatica, which commonly
affects both legs. The pain may radiate to the
toes and may progress to numbness or weak-
ness unless the patient rests.
◆ Spondylolisthesis. A major structural disor-
der characterized by forward slippage of one
vertebra onto another, spondylolisthesis may
produce no symptoms or may cause low back
pain with or without nerve root involvement.
Associated symptoms of nerve root involvement
include paresthesia, buttock pain, and pain radi-
ating down the leg. Palpation of the lumbar
spine may reveal a “step-off” of the spinous
process. Flexion of the spine may be limited.
◆ Transverse process fracture. This type of
fracture causes severe localized back pain with
muscle spasm and hematoma.
◆ Vertebral compression fracture. A verte-
bral compression fracture may be painless