Type III Hypersensitivity (Immune Complex Hypersensitivity)

Type III hypersensitivity, also known as immune complex hypersensitivity, occurs when the immune system mistakenly forms large clusters of antibodies and antigens (foreign substances), called immune complexes. These complexes can accumulate in tissues and trigger inflammation, leading to damage in areas like joints, kidneys, or blood vessels. This type of reaction can result from infections, certain medications, or autoimmune diseases. Symptoms may include pain, swelling, and other signs of inflammation. Essentially, the body's attempt to fight off perceived threats can sometimes harm its own tissues instead.