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What is Characteristic nail finding in lichen planus? and explain in detail?
The nail changes in Lichen planus include: - Irregular longitudinal grooving and ridging of the nail plate. - Pterygium formation(Most characteristic) - Shedding of the nail plate with atrophy of nail bed. - Subungual hyperkeratosis. - Subungual Hyperpigmentation. Pterygium: Loss of small area of the nail plate with proximal nail fold epidermis adherent to the nail bed epidermis (pterygium unguis). Inverse pterygium is seen in systemic sclerosis. 1. Pitting- (i) Psoriasis- Irregular deep pits (Thimble pitting)(ii) Alopecia- Superficial regular pits (iii) Eczema 2. Beau's lines- trauma, hypocalcaemia, malnutrition3. Hyperpigmentation of nails- infection,drugs, dyes, melanoma, etc