Final answer:
Chemical mediators of itching, particularly during allergic reactions, are released by mast cells and include substances like histamine and cytokines. Corticosteroid creams, such as those containing hydrocortisone, help alleviate symptoms like itching and inflammation by suppressing the production of these mediators. However, they may not treat the underlying cause of the allergy.
Step-by-step explanation:
The origin of chemical mediators of itching, specifically in relation to an allergic reaction, often involves the immune system. These chemical mediators are released by mast cells during an allergic response. Upon second exposure to an allergen, IgE antibodies on mast cells recognize the allergen, prompting these cells to release various mediators such as histamine, cytokines, and other compounds.
Histamine, for example, plays a crucial role in causing symptoms associated with allergies, including itching, swelling, mucus production, and inflammation. Eczema, which is characterized by itchy and inflamed skin, often involves an overactive immune response where too many mediators are released. Corticosteroid creams, like hydrocortisone, work by reducing the release of histamine and other mediators, thus providing relief from these symptoms.
In the specific context mentioned, a moisturizing cream, like a topical corticosteroid cream containing hydrocortisone, helps to alleviate the symptoms of allergies such as eczema by acting as an anti-inflammatory agent. This reduces the local production of histamine and other chemical mediators in the skin, suppressing the immune response to reduce inflammation and pruritus (itching).
It is important to note that while such creams can effectively relieve symptoms like itching and inflammation, they may not address the underlying cause of the allergic reaction. They generally provide temporary relief by suppressing the body's inflammatory response to the allergen rather than eliminating the allergen itself.