<prompt> Dermatitis herpetifomis is associated with:HLA DR4HLA DQ2 and HLA DQ8HLACW6HLADR2  <response>: Ans: b HLA DQ2 and HLA DQ8HLA Associations in Bullous DisordersDiseaseAutoantibodiesHLA AssociationPemphigus vulgarisDg IIIHLA DR4HLADR6HLADQ8HLADR14Pemphigus foliaceusDglHLA DR1HLA DR4HLADR14Epidermolysis bullosa acquisitaCollagen type VIIHLA DR2Dermatitis herpetiformisUnknownHLA DQ2HLA DR3HLA DQ8HLADR7DERMATITIS HERPETIFORMIS DHEpidemiologyAge-20 to 40 years, MF, WhitesBlacksAsians EtiologyGenetics: HLA B8, DRw17 and DQw2External factors: Gluten containing diet like wheat, barley, oats and ryeAntigen: Gut epithelial antigen that cross reacts with skinAntibodies: IgA directed against gliadin and autoantigens like reticulin and endomysium PathogenesisGluten or its fragments are taken up by antigen presenting cells like lymphocytesActivation of cytokines and inflammatory cellsPlasma cells release lgA2 directed against gliadinCross-reacts with autoantigens of skin and gut like reticulin, endomyosiumClinical FeaturesIntensely pruriticMost vesicles have been scratched awayChronic recurrent grouped papulo vesicles, symmetricallyMost common on extensor surfaces, back of neck and sacrum, buttocksAssociated with gluten-sensitive enteropathyDiagnosisTzanck smear: Plenty of neutrophilsHistopathology: Neutrophilic microabscesses at the tips of dermal papilla with sub-epidermal vesicleImmunopathology: Clinically normal skin on forearm or buttock shows granular IgA deposits in the dermal papilla.TreatmentStrict gluten free dietSystemic steroids not the mainstay of therapyDapsone 100-200 mgdaySulphapyridine 1.5 gdayTetracycline with nicotinamideColchicine when the above drugs are contraindicated 