True about the lesions of lichen planus -

Ans. is 'd' i.e., All the above Lichen planuso It is a common inflammatory disease affecting the skin, mucous membrane, nails, hair. The atypical lesion is characterized by following characteristics (5Ps)Pruritic (Itching)PolygonalPurple (violaceous)Plane (flat-topped)Papule or plaqueo Exact etiology is not known, but histology suggests an immunological response to an antigen present in the basal cell layers of the epidermis, so it is considered to be an autoimmune disease.Following factors have been implicated:-Drugs thiazides, gold, antimalarials, penicillamines, phenothiazines, quinidine, ACE inhibitorsInfections hepatitis 'C1 virus infection and chronic active hepatitis.Immunological diseases graft versus host disease, primary biliary cirrhosis.Clinical features:-o LP is characterized by shiny, violaceous, flat-topped polygonal papules which retain the skin lines.o White lines, known as Wickham's striae, may traverse the surface of the papules.o Linear lesions often appear along scratch marks or in scars (Koebner phenomenon).o In most cases, the papules eventually flatten after 6 months to 2 yrs, often to be replaced by an area of hyperpigmentation.o LP can affect any part of the body surface but is most often seen on the volar aspect of the wrists, the lumbar region and around the ankles.o Mucous membrane lesions are very common, buccal mucosa and tongue are most often involved.o White streaks, often forming a lacework, on the buccal mucosa are highly characteristic.o Broca phenomenon despite severe pruritus, the patient is don't scratch, because scratching may lead to pain.Nail changes:-Pterygium unguis-most characteristic - Adhesion between the epidermis of the dorsal nail fold and the nail bed may cause partial destruction of the nailExaggeration of the longitudinal lines and linear depressions (MC)Onychorrhexis - splitting of nail tv) Nail atrophy (thinning)Anychia complete loss of nail plate.Longitudinal red lines (red lunula)Pitting.Twenty nail dystrophy of childhood (idiopathic trachyonychia).Longitudinal melanonychiaHyperpigmentation,Subungual hyperkeratosisOnycholysis.o The scalp may lead to cicatricial alopeciao Very rarely ulcerative lesions may lead to squamous cell carcinoma.Treatmento The first line of management is topical corticosteroids. The second choice would be systemic steroid for symptom control and more rapid resolution. Oral antihistamines for pruritus. PUVA for extensive lesions. Acitretin can be used for mucosal lesions.LesionsTreatment of choiceLocalized LPTopical corticosteroids + oral antihistaminicsExtensive LPOral corticosteroids/PUVA/AcitretinLP nail & scalpOral corticosteroidsMucosal LPOral corticosteroids + acitretin or Dapsone