Type III
These reactions are mediated by IgM and IgG antibodies. The antibodies react with an allergen to form an antigen-antibody complex or immunocomplex. Sometimes these complexes can settle on tissue surface and trigger inflammatory reactions. If the macrophages cannot reach them to phagocytize them, enzymes may be released to destroy the complexes. These enzymes damage underlying tissue while destroying the complex.
Depending on where this reaction takes place, it can lead to conditions such as [5]:
- Serum sickness
- Rheumatoid arthritis
- Lupus