Contact dermatitis is a type of Hypersensitivity: (A) Type I, (B) Type II, (C) Type III, (D) Type IV
Answer is D. Table 74.1 CLASSIFICATION OF ADVERSE DRUG REACTIONS BASED ON IMMUNE PATHWAY Type Key Pathway Key Immune Mediators Adverse Drug Reaction Type Type I IgE IgE Uicaria, angioedema, anaphylaxis Type II IgG-mediated cytotoxicity IgG Drug-induced hemolysis, thrombocytopenia (e.g. penicillin) Type III Immune complex IgG + antigen Vasculitis, serum sickness, drug-induced lupus Type IV a T lymphocyte-mediated macrophage inflammation IFN-g, TNF-a TH1 cells Tuberculin, skin test, contact dermatitis Type IV b T lymphocyte-mediated eosinophil inflammation IL-4, IL-5, IL-13 TH2 cells Eosinophils Drug-induced hypersensitivity syndrome (DIHS)Morbilliform eruption Type IV c T lymphocyte-mediated cytotoxic T lymphocyte inflammation Cytotoxic T lymphocytes GranzymePerforin Granulysin (Stevens-johnson syndrome (SJS)/ toxic epidermal necrolysis (TEN) only) SJS/TEN Morbilliform eruption Type IV d T lymphocyte-mediated neutrophil inflammation CXCLB, IL-17, GM-CSF Neutrophils Acute generalized exanthematous pustulosis (AGEP)