Table 4.

Selected important nail signs of systemic disease

NAIL SIGNCOMMONLY ASSOCIATED SYSTEMIC DISEASE
Koilonychia (flat- and spoon-shaped nail plate)Severe iron deficiency anemia
Proximal splinter hemorrhagesBacterial endocarditis
Antiphospholipid syndrome
Arterial emboli
Thrombocytopenia
Vasculitis
Trichinosis
Apparent leukonychia (white nails, the colour of which fades with pressure)Half and half nails (white proximal half)

  • renal disorders


Terry nails

  • hepatic disorders,

  • chronic congestive heart failure, and

  • adult-onset diabetes mellitus


Muehrcke lines (multiple transverse whitish bands)

  • systemic chemotherapy and

  • hypoalbuminemia

Ventral pterygium (adhesion of the distal nail plate to the hyponychium)Scleroderma
Clubbing (enlarged and excessively curved nail plate, causing more than 180° widening of the angle between the proximal nail fold and the nail plate)If unilateral, neurologic (hemiplegia) and vascular disorders
If bilateral, pulmonary, cardiac, gastrointestinal, infectious, and endocrine diseases
Nail fold capillary abnormalities (reduced capillary density and avascular areas alternating with dilated capillary loops)Dermatomyositis
Scleroderma