<prompt> A male patient comes with recurrent vesicles and erosions on the groin and axilla ,what is the diagnosis ?PemhigusHailey-Hailey DiseaseTinea CrurisInverse Psoriasis  <response>: Hailey-hailey diseasechronic benign familial pemphigus - -recurrent flaccid vesicles develop over inter-triginous area flexors - groin, axilla - Occurs due to defect in ATP2C I gene - ATP2C I gene codes for SERCA Sarco Endoplasmic reticulum Ca2 ATPase. Therefore, in this disease Ca2 ATPase is defective. - Ca2 required for attachment of two desmosomes which doesnt happen in this disease resulting in separation of keratinocytes i.e. acantholysis. - Autosomal Dominant CF: - recurrent flaccid vesicles develop over inter-triginous area flexors - groin, axilla - Dt friction at flexor region - rupture of these lesions occurs leading to erosion.- Nail: longitudinal white bands. Histology: Dilapidated Brick wall appearance Pemphigus - presents with blisters in mouth genitals Tinea crurisdhobis itch - fungal infection causing infection in groin region caused by Trichophyton. Inverse psoriasis - presents with red inflamed lesion in the skin folds of the body, therefore aka interiginous psoriasis. 