Can Histology Identify Hypersensitivity Reactions?
Yes, hypersensitivity reactions can be identified histologically. These reactions are classified into four types:
- Type I (Immediate Hypersensitivity): Characterized by mast cell degranulation and the presence of eosinophils, as seen in allergic reactions. - Type II (Cytotoxic Hypersensitivity): Marked by antibody-mediated cell destruction, observable in conditions like autoimmune hemolytic anemia. - Type III (Immune Complex-Mediated Hypersensitivity): Immune complex deposition leads to inflammation and tissue damage, typical of systemic lupus erythematosus. - Type IV (Delayed-Type Hypersensitivity): Involves T-cell-mediated responses, leading to granuloma formation, as seen in tuberculosis.
