Type III allergy

Type III allergy is understood as an allergic immune complex reaction mediated by antibodies (IgG, IgA, IgM). Immune complexes of antibodies and antigens are formed after contact with an allergen. Special components of the complement system induce phagocytosis (active uptake) of the immune complexes by granulocytes by releasing tissue-damaging enzymes. The allergic reaction occurs after 6 to 12 hours. Other immune complexes are deposited in tissues, where they lead lead to allergic inflammatory reactions. A typical clinical profile of a type III allergy is exogenous allergic alveolitis, caused by microorganisms (bacteria, fungi) or poultry excrement (Farmer's lung, bird keeper's lung).