ihoherkistymistä

Ihoherkistyminen, also known as skin sensitization, is an immunological process where repeated exposure to a substance leads to an allergic reaction upon subsequent contact. This is distinct from simple skin irritation, which is a direct toxic effect on the skin. Sensitization involves the immune system recognizing a substance as foreign and initiating a specific response.

The process typically occurs in two phases. The induction phase involves initial exposure(s) to the sensitizing agent, called an allergen. During this phase, the allergen penetrates the skin and is processed by immune cells, leading to the development of specific T cells that are primed to recognize the allergen. This phase may not involve any visible signs of reaction. The elicitation phase occurs upon re-exposure to the same allergen. The primed immune cells recognize the allergen and trigger an inflammatory response, resulting in the characteristic symptoms of allergic contact dermatitis.

Symptoms of skin sensitization, when it manifests as allergic contact dermatitis, can include redness, itching, swelling, blistering, and dryness or cracking of the skin at the site of contact. The severity of the reaction can vary depending on the individual's immune system and the concentration and duration of exposure to the allergen. Common allergens include certain metals like nickel, fragrances, preservatives in cosmetics, and poison ivy. Identifying and avoiding the causative allergen is the primary method of managing skin sensitization.