# Nail Signs in Systemic Disease > Nail signs in systemic disease — clubbing, Terry, Lindsay, Muehrcke, Beau lines — high-yield NEET-PG Medicine revision notes. - Canonical URL: https://prepelephant.com/topics/neet-pg/medicine/nail-signs-systemic-disease - Exam / course: NEET-PG · Subject: Medicine - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-02 - Last updated: 2026-10-02 - How to cite: "Nail Signs in Systemic Disease", PrepElephant, https://prepelephant.com/topics/neet-pg/medicine/nail-signs-systemic-disease ## Direct answer Clubbing, leukonychia and splinter haemorrhages turn a nail examination into a systems screen: Schamroth's positive window and a Lovibond angle above 180 degrees flag clubbing of cardiac, pulmonary or gastrointestinal origin; Terry's proximal white nails accompany cirrhosis in up to 80% of cases in classical series; the half-and-half (Lindsay) nail belongs to chronic renal failure; and paired Muehrcke bands track serum albumin below roughly 2.2 g/dL. For NEET-PG Medicine, the decisive viva skill is separating true nail-plate signs, which migrate as the nail grows, from nail-bed signs, which stay put. ## What you must remember - Clubbing: loss of the diamond-shaped Schamroth window; Lovibond angle greater than 180 degrees; causes include lung cancer, bronchiectasis, cyanotic congenital heart disease, infective endocarditis, inflammatory bowel disease and cirrhosis. - Koilonychia (spoon nails): iron deficiency anaemia and Plummer-Vinson syndrome; a degree is physiological in infants. - Terry's nails: proximal 80% white with a distal pink band — cirrhosis (reported in up to 80%), chronic cardiac failure, diabetes and ageing. - Lindsay half-and-half nails: proximal white, distal reddish-brown band over about 20–60% of the nail — chronic renal failure, seen in a substantial proportion of dialysis patients. - Muehrcke's nails: paired, parallel white transverse bands of the nail bed that do not move with growth; classically with serum albumin below about 2.2 g/dL in nephrotic syndrome. - Beau lines: transverse depressions in the plate itself after high fever, chemotherapy or severe illness — they migrate distally at roughly 3 mm per month for fingernails. - Mees lines: true plate leukonychia after arsenic or thallium exposure, also migrating with growth. - Splinter haemorrhages: linear red-brown streaks; proximal or multiple lesions raise endocarditis, though distal single lesions are usually traumatic. - Pitting with oil-drop discolouration and onycholysis means nail psoriasis; trachyonychia and geometric pitting suggest alopecia areata. - Yellow nail syndrome triad: slow-growing yellow nails, lymphoedema and pleural effusion. - Pterygium — scarring wing from proximal nail fold — marks lichen planus. ## How to reason through the examination A 54-year-old alcoholic with distension of the abdomen extends his hands: all ten nails are white in their proximal four-fifths with a narrow distal pink rim, and the index fingers show faint paired transverse pale bands. Step one: name the signs — Terry's nails first; the paired bands need one decisive test: bands that stay fixed while the plate grows over months are Muehrcke bands of the bed, explained by his ascites and heavy proteinuria through hypoalbuminaemia. Step two: contrast the mimics in one sentence for the examiner — a Beau line or Mees line sits in the plate and marches distally, whereas Muehrcke's lines are bed phenomena that stay still; mixing them is the classic penalty. Step three: complete the systemic sweep that the nails provoke — examine for clubbing and spider naevi, completing the cirrhotic's hand; look for splinter haemorrhages with a new murmur to prompt blood cultures for endocarditis; note half-and-half discolouration and ask about uraemia and dialysis. Step four: localise before systematising — distal onycholysis with oil-drop salmon patches points to psoriasis; proximal whitening with pterygium points to lichen planus and warrants a mucosal examination for the reticular rash. Step five: use growth kinetics prospectively — a Beau line dated from a dengue admission lets you estimate nail growth and reassure the patient that the furrow will grow out. ## Where students slip The commonest slip is presenting every white line as "leukonychia due to calcium deficiency" — true leukonychia reflects keratinisation and trauma, not calcium, and the exam expects the protein-related nail-bed bands instead. The second is failing the fixed-versus-mobile test between Muehrcke and Mees/Beau. Third, quoting Terry's nails for "anaemia" rather than cirrhosis, cardiac failure and diabetes loses the association mark. Fourth, single distal splinter haemorrhage treated as proof of endocarditis — the stem will say "multiple, proximal, with fever and murmur" when it wants the blood cultures. Finally, forgetting yellow nail syndrome's triple presentation when a stem pairs pleural effusion with lymphoedema. ## Frequently asked questions ### How is clubbing confirmed at the bedside? Schamroth's window test — opposing the dorsal surfaces of two fingers from the same hand normally leaves a diamond-shaped gap; obliteration of this window, with Lovibond angle exceeding 180 degrees, confirms clubbing. ### What is the difference between Muehrcke and Mees lines? Muehrcke's lines are paired white bands in the nail bed that do not migrate with nail growth and classically accompany hypoalbuminaemia; Mees lines are in the nail plate itself, migrate distally, and follow arsenic or thallium exposure. ### Which nail sign is associated with chronic renal failure? The half-and-half (Lindsay) nail — proximal white discolouration with a distal reddish-brown band — common in uraemia and dialysis. ### What causes Beau lines? Transient arrest of nail matrix activity during severe systemic illness, high fever or chemotherapy, producing transverse plate depressions that grow out at about 3 mm per month. ### Which nail features characterise psoriasis? Pitting, oil-drop salmon discolouration, onycholysis beginning distally, and subungual hyperkeratosis — distinguished from onychomycosis by KOH negativity and asymmetry.