Redness of the skin, known as erythema, often occurs due to the dilation of blood vessels in response to an irritant or allergen. In the context of toxicology, this can be triggered by exposure to chemical irritants, such as acids or bases, which can disrupt the skin barrier and cause inflammation. Additionally, allergic reactions to specific substances can also lead to erythema, mediated by the release of histamines and other inflammatory mediators.
