Delayed hypersensitivity may be induced by?

Delayed hypersensitivity is a type of immune response that typically takes hours to days to develop after exposure to an antigen. It is mediated primarily by T lymphocytes (T cells) rather than antibodies, which are primarily involved in immediate hypersensitivity reactions.

Contact sensitivity to inorganic chemicals is a classic example of a mechanism that can induce delayed hypersensitivity. When an individual is exposed to certain inorganic chemicals—such as nickel or chromium—they may develop a sensitization after initial contact. Upon subsequent exposure, the immune system recognizes the foreign substances, leading to a cell-mediated immune response characterized by inflammation and tissue damage at the site of contact. This process can result in conditions like allergic contact dermatitis, which manifest as a delayed immune response.

The other options, while related to different types of immune processes, do not specifically align with the mechanism described for delayed hypersensitivity. Food allergies are typically associated with immediate hypersensitivity reactions, where antibodies (IgE) react rapidly to allergens. Immediate allergic reactions also refer to similar mechanisms involving IgE and mast cell degranulation, which is distinct from the T cell-mediated response of delayed hypersensitivity. Genetic factors can influence overall immune response and susceptibilities but are not specific in inducing delayed hypersensitivity in the absence of a triggering antigen