All are true/ except regarding patch test
C. i.e. Angry back lit false negative test The gold standard method for the diagnosis of allergic dermatitis resulting from type IV delayed hypersenstivityQ. Such as allergic contact dermatitis (ACD) & air borne contact dermatitis (ABCD)Q remains the patch test. It is read after 48 hours (2 days)Q Type 1 hypersensitivity (eg atopic dermatitis) is detected by prick test (of debatable significance). And type IV delayed hypersensitivity (eg contact dermatitis) is diagnosd by patch skin test (gold standard). So skin test can be done for Type I (atophy) & type IV (contact dermatitis). Type of hypersensitive reaction Clinical Syndrome Type I : IgE type AnaphylaxisQ AtopyQ (prick test) Type II : Cytolytic & Antibody mediated damage? Cytotoxic Thrombocytopenia- agranulocytosis, hemolytic anemia etc. Type III : Immune Ahrus reaction complex Serum sickness Type IV : Delayed Tuberculosis Hypersensitivity Contact dermatitis (patch test)Q
Diagnose ABCD
Read after 48 hours
Angry back IA false negative test
T.R.U.E test