blister

blister, puffy swelling of the outer skin (epidermis) caused by burn, friction, or irritants like poison ivy. A response of the body to protect deeper tissue, blisters generally contain serum, the liquid component of blood. The so-called blood blister, however, forms over ruptured capillaries and therefore contains whole blood.

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blister

Rounded skin elevation in which fluid fills a separation between layers of epidermis or between the epidermis and the dermis. The fluid is usually clear; yellowish fluid contains pus, and red fluid contains blood. Blisters often occur on the palms or soles when pressure and friction cause an upper skin layer to move back and forth over the one under it. A small gap opens between them and becomes filled with fluid. This type generally heals spontaneously, sometimes leaving a thickened callus. Blisters that occur as symptoms of contact dermatitis, viral infection, or autoimmune disease can appear anywhere on the body and may leave scars.

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blister

1. a small bubble-like elevation of the skin filled with serum, produced as a reaction to a burn, mechanical irritation, etc

2. a transparent dome or any bulge on the fuselage of an aircraft, such as one used for observation

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blister [′blis·tər]

(engineering)

A raised area on the surface of a metallic or plastic object caused by the pressure of gases developed while the surface was in a partly molten state, or by diffusion of high-pressure gases from an inner surface.

(geology)

A domelike protuberance caused by the buckling of the cooling crust of a molten lava before the flowing mass has stopped.

(graphic arts)

A damaged area on a photographic material where the emulsion has separated from the base.

(materials)

A roughly circular or elliptic unbonded area between plies of a laminated material; usually caused by trapped moisture. Also known as steam blow.

(medicine)

A local swelling of the skin resulting from the accumulation of serous fluid between the epidermis and true skin.

(mining engineering)

A protrusion, more or less circular in plan, extending downward into a coal seam.

(nucleonics)

A protuberance that sometimes develops on the surface of a nuclear-reactor fuel element during use, generally because of entrapped gases.

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blister

1. A roughly circular or elongated unbonded area between plies of laminated constructions, as in wood veneer. Usually caused by entrapped moisture. Also called steam blow.

2. A spongy raised portion of a roofing membrane, where separation of the felts has occurred or the membrane is not bonded to the substrate as a result of the expansion of water and air trapped in the membrane.

3. A raised spot on the surface of the metal caused by expansion of gas in a sub-surface zone during thermal treatment.

4. A raised area on the surface of a molded plastic caused by the pressure of internal gases on its incompletely hardened surface.

5. See blistering

6. A convex, raised area on the surface of a pipe which indicates an internal separation.