<prompt> The characteristic Nail finding in lichen planus is :PittingPterygiumBeaus linesHyperpigmentation of the Nails  <response>: Ans. is b Pterygium?e. Page 191, 4e, Pasricha Nail Findings in lichen planusNail involvement is seen in 10 of pts with lichen planusMild form of Nail involvement Onychorrhexis - Slight roughness of Nail plate with longitudinal ridging and brittleness.Severe form of Nail involvement: Anychia-Complete absence of nail plate Pterygium-Skin fold from post nail fold starts overgrowing the nail plate to form pterygium.Other Disorders of Nail 1 Beaus Line-Any severe systemic illness.2 Oncholysis-Psoriasis Fungal infection Thyrotoxicosis Tetracycline Trauma3 Pitting-Psoriasis Alopecia Areata Lichen Planus Eczema4 Ridging-Lichen Planus5 Koilonychia-Iron deficiency Anaemia Lichen planus Repeated exposure to detergents.6 Muehrckes nail-Severe hypoalbuminemia as in Nephrotic syndrome.7 Blue nails-Wilsons disease Hemochromatosis Antimalarial drug8 Brown nail-Addisons disease Arsenic poisoning9Leukonychia-Liver disease10 Mees Line-Arsenic poisoningNote : Nail involvement is not seen in DLE. 