Nails

Nail Discoloration

Nail Discoloration, Leukonychia, Melanonychia, Chromonychia, White Nails, Yellow Nails, Black Nails, Red Nails, Blue Nails

Anemia (most common)
Congenital (Autosomal Dominant)
1. Abnormal keratinization of underlying nail matrix
2. Results in nail plate white discoloration of one or multiple nails with all or partial nail involvement
3. No Clinical Significance (normal variant in adults and children)
Terry's Nails (all White Nails except the distal 1-2 mm nail edge)
1. Chronic Liver Disease
2. May also occur with Diabetes Mellitus, Congestive Heart Failure, Hyperthyroidism, Aging
Half and Half Nails (Lindsay's Nails, white proximal, pink/red distal)
1. Chronic Renal Failure
Transverse Linear Nail Lesions
1. Muehrcke's Lines
2. Mees' Lines
3. Transverse striate Leukonychia (white lines)
  1. Minor nail matrix or cuticle Trauma
Leukonychia punctata (white spots)
1. Minor Trauma to Nail Cuticle or matrix

See Nail Abnormality for other longitudinal striations
Nail Hyperpigmentation is common
1. Black patients have a 75% Prevalence of benign nail Hyperpigmentation
2. However, involvement of a single nail (esp. first), and esp. in a linear arrangement is concerning
  1. Represents Subungual Melanoma in 5% of caucasian and 15-20% of black, asian
Subungual Melanoma
1. Most important diagnosis to exclude
Vertical Nail Bands (Longitudinal Melanonychia)
1. Hyperpigmented bands occur as normal variant in 90% of black patients
2. Distinguish from Subungual Melanoma (see below)
Medication Side Effects
1. Cyclophosphamide (Cytoxan)
2. Excessive Fluoride Supplementation (Fluorosis)
Melanonychia striata
1. Common in dark skinned persons
2. Spontaneous or secondary to Trauma or Chemotherapy
Benign Nevus
1. Uniform brown longitudinal streak localized to nail
Chronic Renal Failure
1. Distal nail bed discolored brown