WHEAL RESPONSE Meaning and
Definition
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The "wheal response" is a physiological reaction of the human body to certain stimuli. More specifically, it refers to the formation of a localized area of raised and reddened skin, also known as a wheal, as a result of a specific triggering factor.
This response is commonly observed in allergic reactions, particularly in the context of skin testing for allergies. When the body is exposed to an allergen such as pollen, pet dander, or certain foods, it recognizes the substance as foreign and initiates an immune response. As part of this response, the body releases specific chemicals, such as histamine, which cause blood vessels in the affected area to dilate and become more permeable.
The dilation and increased permeability of the blood vessels allow fluid to leak into the tissues, resulting in the appearance of a wheal. This raised, reddened area often itches and can vary in size. The wheal response is typically observed within minutes after exposure to the allergen and may persist for a variable duration depending on the individual's sensitivity and immune system's response.
The wheal response is commonly used as a diagnostic tool in allergy testing. By introducing small amounts of potential allergens into the skin through scratching or injection, healthcare professionals can assess an individual's immune response and identify specific allergens to which they may have sensitivity.
In summary, the wheal response refers to the formation of a localized raised and reddened area of the skin, commonly seen in allergic reactions as a result of increased blood vessel permeability.
Etymology of WHEAL RESPONSE
The term "wheal response" is derived from the Middle English word "whele" and the Old English word "hwēol". Both words referred to a raised, swollen, or puffy area on the skin. In the context of medicine, the word "wheal" specifically denotes a raised area that appears after the skin has been pricked or scratched. The term "response" is added to indicate that it is an indication or reaction of the body's immune system to allergens or irritants. Therefore, the etymology of "wheal response" can be traced back to Old English and Middle English terms referring to a raised skin reaction.
