Max. Joseph's space is a histopathological feature of

Max Joseph space/cleft is a histological feature of lichen planus . It is an idiopathic chronic inflammatory condition affecting the skin, mucous membrane and appendages. The 6Ps of lichen planus are purple, papule, pruritic, polygonal, plaque, plane/flat-topped. Delicate white striae - Wickham's striae seen due to focal thickening of granular cell layer. The finding is enhanced by applying oil or by using dermoscopy. Positive Koebner's phenomenon -linear distribution of lesions following trauma. Classic form is the most common variant Nail findings- diffuse nail ridging and dorsal pterygium twenty nail syndrome (trachyonychia)-nail roughness caused by excessive longitudinal ridging may involve all 20 nails Diagnosis: Histological features -compact hyperkeratosis,wedge-shaped hypergranulosis,irregular acanthosis,sawtoothing of rate ridges and vacuolar damage to basal cell layer, degenerated keratinocytes in the upper dermis called civatte bodies or colloid bodies. Interface inflammation causes a small separation between epidermis and dermis called max joseph space/cleft Associated conditions -HCV association is very impoant alopecia areata vitiligo DLE Diabetes mellitus Ulcerative colitis First line therapy is topical coicosteroids Ref Harrison 20th edition pg 1278