Webster's New World Medical Dictionary

eosinophilic granuloma
A disease in which
histiocytes multiply and attack the tissues, forming
solitary or multiple eosinophilic granulomas.
Eosinophilic granuloma predominantly affects chil-
dren and young adults. It is the most common type
of Langerhans cell histiocytosis. In patients with
eosinophilic granuloma, granulomas may develop
in bone, with overlying tender and sometimes warm
areas of swelling with an inability to bear weight.
ependymoma
A type of brain tumor that derives
from the glial cells that line the cavities within the
brain’s ventricles. Because cerebrospinal fluid nor-
mally flows through these ventricles, blockage due
to an ependymoma can cause buildup of fluid, pres-
sure on the brain, and hydrocephalus.
ephedrine
A vasoconstricting, bronchodilating
drug that is used to treat asthma and also found in
over-the-counter remedies for cold and flu symp-
toms and in some herbal remedies (in the form of
the ephedrine-containing herbs ephedra or Ma
Huang). Side effects of ephedrine can include jitter-
iness, racing heartbeat, nausea, sleeplessness, and
headache. Ephedrine misuse or abuse can be dan-
gerous and even life-threatening, especially for peo-
ple with heart conditions.
epicanthal fold
A fold of skin that comes down
across the inner angle of the eye. Epicanthal folds
appear most frequently in persons with Down syn-
drome and some other constellations of birth
defects. To the untrained eye, an epicanthal fold may
look similar to the eye fold found in peoples of
Asian origin, but the normal Asian eye fold is actu-
ally quite distinct, whereas an epicanthal fold is con-
tinuous with the lower edge of the upper eyelid.
epicardium
See 
pericardium, visceral.
epidemic
The occurrence of more cases of a dis-
ease than would be expected to occur in a commu-
nity or region during a given time period. A sudden
outbreak (as, for example, of cholera). See also
endemic; pandemic.