Nail Discoloration


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

  • Definitions
  • Chromonychia
  1. Color changes of nails
  • Causes
  • White Nail - Leukonychia (partial or complete)
  1. Anemia (most common)
  2. 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)
  3. 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
  4. Half and Half Nails (Lindsay's Nails, white proximal, pink/red distal)
    1. Chronic Renal Failure
  5. Transverse Linear Nail Lesions
    1. Muehrcke's Lines
    2. Mees' Lines
    3. Transverse striate Leukonychia (white lines)
      1. Minor nail matrix or cuticle Trauma
  6. Leukonychia punctata (white spots)
    1. Minor Trauma to Nail Cuticle or matrix
  • Causes
  • Miscellaneous Color Changes
  • Causes
  • Blue Nails
  1. Medication Side Effect
    1. Quinacrine
    2. Chloroquine
    3. Minocycline (Minocin)
    4. Doxorubicin (Adriamycin)
    5. Melphalan, Bleomycin, Daunorubicin
  2. Wilson's Disease (Azure lunula)
  3. Ochronosis
  4. Psoriasis
  5. Alopecia Areata
  6. Silver Poisoning (Argyria)
  • Causes
  • Black Nails (Melanonychia) or dark longitudinal streaks
  1. See Nail Abnormality for other longitudinal striations
  2. 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
  3. Subungual Melanoma
    1. Most important diagnosis to exclude
  4. Vertical Nail Bands (Longitudinal Melanonychia)
    1. Hyperpigmented bands occur as normal variant in 90% of black patients
    2. Distinguish from Subungual Melanoma (see below)
  5. Medication Side Effects
    1. Cyclophosphamide (Cytoxan)
    2. Excessive Fluoride Supplementation (Fluorosis)
  6. Melanonychia striata
    1. Common in dark skinned persons
    2. Spontaneous or secondary to Trauma or Chemotherapy
  7. Benign Nevus
    1. Uniform brown longitudinal streak localized to nail
  8. Chronic Renal Failure
    1. Distal nail bed discolored brown
  • References
  1. Jhun, Raam and DeClerck in Herbert (2015) EM:Rap 15(12): 3-4
  2. Fawcett (2004) Am Fam Physician 69(6):1417-24 [PubMed]