Which hormone is released during allergic responses and causes inflammation?

Histamine is a key player in the body's allergic response. When the immune system encounters an allergen, it triggers the release of histamine from mast cells and basophils. This release leads to various physiological effects that are characteristic of allergic reactions, including inflammation, increased blood flow, and the dilation of blood vessels. These changes result in symptoms such as swelling, redness, itching, and mucus production in the affected areas.

The role of histamine is crucial because it is primarily responsible for the immediate hypersensitivity reactions that occur during allergies. It acts on different receptors in various tissues, which is why allergic reactions can manifest in diverse ways depending on the site of exposure (e.g., skin, respiratory tract).

Other hormones, such as cortisol, adrenaline, or substances like histognin, may have different functions in the body and are not primarily responsible for initiating or causing inflammation related to allergic responses. Cortisol, for instance, is a stress hormone with anti-inflammatory properties. Adrenaline, while involved in the body's fight-or-flight response, does not directly mediate allergic inflammation. Histognin is not recognized as a significant hormone in this context. Thus, histamine stands out as the primary substance involved in causing inflammation during allergic reactions.