Dictionary

economy-class syndrome See deep vein thrombosis.

ecstasy 1 A state of rapture and trancelike elation. 2 A street name for 3, 4-methylenedioxymethamphetamine (MDMA), a synthetic, mind-altering drug with hallucinogenic and amphetamine-like properties—other street names include “Adam” and “XTC.” Its chemical structure is similar to two other synthetic drugs, MDA and methamphetamine. See also designer drug.

ECT Electroconvulsive therapy.

ectoderm The outermost of the three primary germ cell layers (the other two being the mesoderm and endoderm) that make up a very young embryo. The ectoderm differentiates (specializes) to give rise to many important tissues and structures, including the outer layer of the skin and its appendages (such as the sweat glands, hair, and…

ectodermal dysplasia A genetic disorder in which the skin and associated structures (the hair, nails, teeth, and sweat glands) develop abnormally. X-linked anhidrotic (nonsweating) ectodermal dysplasia is most common; because it is an X-linked trait, it mainly affects males. There is also an autosomal dominant form that affects both males and females. The term ectodermal…

-ectomy The surgical removal of something. For example, a lumpectomy is the surgical removal of a lump, a tonsillectomy is the removal of the tonsils, and an appendectomy is removal of the appendix.

ectopia cordis A birth defect that results in an abnormal location of the heart, usually outside the chest.

ectopic In the wrong place, out of place. For example, an ectopic kidney is a kidney that is not in the usual location.

ectopic pregnancy A pregnancy that occurs outside of the uterus. Usually, ectopic pregnancies occur because a fertilized egg settles and grows in a Fallopian tube. However, ectopic pregnancies can occur in other locations, such as the ovary, cervix, and abdominal cavity. An ectopic pregnancy is usually due to the inability of a fertilized egg to…

eczema An inflammatory reaction of the skin in which there are tiny blister-like raised areas in the early stage followed by reddening, swelling, bumps, crusting, and thickening and scaling. Eczema characteristically causes itching and burning. Also known as atopic dermatitis. Eczema is a very common skin problem that may start in infancy, later in childhood,…

eczema, allergic contact A red, itchy, weepy reaction that occurs where the skin has come into contact with a substance that the immune system recognizes as foreign, such as poison ivy or certain preservatives in creams and lotions. Also known as allergic contact dermatitis.

eczema, contact A localized reaction that involves redness, itching, and burning that occurs where the skin has come into contact with an allergen (an allergy-causing substance) or an irritant such as an acid, a cleaning agent, or another chemical.