Table 1.

Gell and Coombs classification of hypersensitivity reactions.

Type I	IgE antibody-mediated reactions, e.g., anaphylaxis
Type II	Antibody-mediated cytotoxic reactions, e.g., hemolytic anemia, thrombocytopenia, blood transfusion reactions
Type III	Immune complex-mediated hypersensitivity, e.g., serum sickness, vasculitis
Type IV	Delayed T cell-mediated responses, e.g., allergic contact dermatitis, maculopapular exanthema, erythema multiforme, toxic epidermal necrolysis, Drug-induced hypersensitivity syndrome (DiHS), hypersensitivity pneumonitis