Reference Terms
from Wikipedia, the free encyclopedia


Urticaria or hives is a relatively common form of allergic reaction that causes raised red skin welts.

Urticaria is also known as nettle rash or uredo.

These welts can be 5 mm (0.2 inches) in diameter or more, itch severely, and often have a pale border.

Urticaria is generally caused by direct contact with an allergenic substance, or an immune response to food or some other allergen.

Hives can be caused by stress.

Note:   The above text is excerpted from the Wikipedia article "Urticaria", which has been released under the GNU Free Documentation License.
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May 23, 2017

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