The itch associated with eczema is a result of chronic irritation and the inflammation of your skin. It may be genetic in origin or be triggered by contact with a common allergen, such as poison oak or nickel. Eczema is usually located on areas of your skin that have thin epithelial barriers, allowing for irritants and allergens to promote inflammation. As a consequence, certain molecules get released that cause the sensation of itching. Scratching your skin only weakens the skin barrier more, resulting in more inflammation and eczema flares.
The best method to neutralise the eczema itch is help preserve the integrity of your skin barrier. This is done by moisturising your skin, often several times daily. Hypoallergenic creams and ointments are usually preferred. When moisturisers fail to neutralize itching, doctors often prescribe topical corticosteroids which reduce the inflammation when applied to your skin. They should be used sparingly, though, as they have the potential to thin out skin, especially when used on your face. Rarely, corticosteroids or other immunosuppressants taken by mouth may be used in severe cases. Antihistamines, such as diphenhydramine, do little to help the itching associated with eczema and accomplish more with their sedative properties to help a person with eczema get a good night's rest.