Ans. b. Suprabasal (Ref: Fitzpatrick 7/e p45-47, 349, 459-84, 1714, 1878, 1892; Rooks Textbook of Dermatology 8/e p40.3-40.64)Bulla on body and oral mucosa in a 50 years old male is suggestive of Pemphigus vulgaris.Pemphigus vulgaris:Characterized by cutaneous (thin walled, delicate and flaccid bullae)Q and mucosal blisters.Mucosal lesions are present in all patients, oral mucosa most frequently involved, painful erosions extend peripherally with shedding of mucosaQ.Bulla is intra-epidermalQ, the split being suprabasalQ.Presence of acantholytic cells (rounded keratinocytesQ present in the blister cavity and at the edge of the blister) with row of tombstone appearanceQ.A 30-year-old male presents with flaccid bullae on an erythematous base and erosions over the oral mucous membrane. The blisters developed painful erosions rupture. The clinical features point towards a diagnosis ofpermphigus vulgaris, which is characterized by fish net pattern of intraepidermal IgG deposition on immunofluorescence.DisorderImmunofluorescencePatternTarget antigenPemphigus vulgarisIntercellular, intraepidermalQIgG, fish netQDesmoglein 3QPemphigus foliaceusIntercellular, intraepidermalQIgG, fish netQDesmoglein 1QParaneoplastic pemphigusIntercellular and subepidermalQIgG, fish netQPlakins (desmoplakin, envoplakin, periplakin, BP 230)Bullous pemphigoidBasement membrane zoneQIgG, linearQBP230> BP180Herpes gestationalisBasement membrane zoneQIgG, linearQBP230 > BP 180Dermatitis herpetiformisDermal papillaeQIgA, granularQ(?) Epidermal tissue trnasgl utam inaseQLinear IgA diseaseBasement membrane zoneQIgA, linearQBP180PemphigusAutoimmune disease characterized by acantholysis induced by deposition oflgG antibodies in the intercellular area of epidermisQCommonest variant is Pemphigus vulgaris, seen in adults mainlyQMainly involve upper part of the bodyQCharacterized by cutaneous (thin walled, delicate and flaccid bullae)Q and mucosal blistersMucosal lesions are present in all patients, oral mucosa most frequently involved, painful erosions extend peripherally with shedding of mucosaQErosions are frequently secondarily infectedQ (by bacteria in skin and Candida in mucosa), extensive lesions are associated with water and electrolyte imbalanceQAssociated with Nikolsky signQ and Bulla spread sign or Asboe Hansen signQ.Histology (Biopsy is best taken from the edgeQ, from perilestonal skinQ)Bulla is intra-epidermalQ, the split being suprabasalQPresence of acantholytic cells (rounded keratinocytesQ present in the blister cavity and at the edge of the blister)Row of tombstone appearanceQDirect Immunofluorescence (DIF):Done on skin, shows intercellular deposits of IgG and C3 giving a fish net appearanceQTreatment:Systemic steroids and immunosuppressants.Types of BullaeIntra-EpidermalSub-Epidermal* PemphigusQ* Herpes simplex/zosterQ* Molluscum contagiosumQ* Variola/varicelia* Eczema* Darriers disease* Miliria rubra* Pompholyx* PemphigoidQ* Dermatitis herpetiformisQ* Herpes gestationalisQ* BurnsQ* Erythema multiformeQ* Epidermolysis bullosa* Lichen planus bullosa