ärritäjä

An irritant is a substance that causes a local inflammatory reaction or other adverse effect upon contact with a body surface such as the skin, eyes, or respiratory tract. This reaction is typically a response to the substance's ability to interact with tissues and trigger a defense mechanism. Irritants can be chemical, physical, or biological in nature.

Chemical irritants include a wide range of substances. Acids and bases, for example, can denature proteins in tissues, leading to burns and inflammation. Solvents can dissolve lipids in cell membranes, disrupting tissue integrity. Some chemicals cause irritation through specific receptor interactions, triggering pain or itching sensations. The severity of irritation depends on the concentration, duration of exposure, and the specific chemical properties of the irritant.

Physical irritants are non-chemical agents that can cause damage. Examples include rough surfaces that cause friction or abrasion on the skin, extreme temperatures (both heat and cold) that can damage cells, and particulate matter like dust or sand that can physically scratch or block airways. Radiation, such as ultraviolet light, can also act as a physical irritant, causing sunburn and other tissue damage.

Biological irritants are living organisms or their products that can provoke an inflammatory response. Certain plants, like poison ivy, contain oils that cause allergic contact dermatitis. Some microorganisms can release toxins that irritate tissues. Even certain animal venoms or secretions can be irritants.

Symptoms of irritation vary depending on the site of contact and the nature of the irritant. Skin irritation may manifest as redness, itching, burning, swelling, or rash. Eye irritation can cause redness, watering, stinging, and light sensitivity. Inhalation of irritants can lead to coughing, wheezing, shortness of breath, and inflammation of the airways. Prompt removal of the irritant and appropriate treatment are often necessary to alleviate symptoms and prevent further damage.