<prompt> Max Joseph space is related to -PsoriasisPityriasisLichen planusScabies  <response>: Ans. is c i.e., Lichen planus Histological feature of lichen planusThe earliest finding is an increase in epidermal Langerhans cells, associated with a superficial perivascular infiltrate of lymphocytes and histiocytes, impinging on the dermal-epidermal junction DEJ.Mild spongiosis is followed by vacuolar alteration and clefting along the DEJ, with accumulation of necrotic keratinocytes colloid bodies.Irregular acanthosis of the epidermis, irregular thickening of the granular layer, and compact hyperkeratosis.A focal increase in thickness of the granular layer and infiltrate corresponds to the presence of Wickhams striae. Degenerating basal epidermal cells are transformed into colloid bodies 15-20 im diameterThe rete ridges may appear flattened or effaced saw-tooth appearance, and focal separation from the dermis may lead to max Joseph spaces.In active L P, a band-like infiltrate of lymphocytes and histiocytes, rarely admixed with plasma cells obliterates the DEJ.Epidermal melanocytes are absent or considerably decreased in number, while pigmentary incontinence with dermal melanophages is characteristic. 