Chromonychia L60.8 L60.9

Discoloration of the nails (nail surface, nail plate and/or subungual tissue).

• Grey or grey-blue nail coloration:
  • Argyrie (slate grey; rare today)
  • Phenolphthalein
  • metastatic malignant melanoma
  • Mercury chloride.
• Red or red-blue nail colouring:
  • two-dimensional: fresh haematoma
  • fine linear from the free nail edge:
    • Splinter hemorrhage
    • Erythronychia, localized longitudinal.
• Blue or blue-brown (diffuse) nail colouring:
  • Blue discoloration in combination of cardiac vitium and cyanotic flail fingers and toes
  • Medicines: Minocycline, Mepacrin, Chloroquine, Doxyrubicin
  • Systemic diseases: M. Wilson.
• Green or green-black nail colouring:
  • Pseudomonas infections (green discoloration due to the fluorescent dye of the pathogens, pyoverdin)
  • Mould infection (see Tinea unguium below).
• Yellow or yellow-brown nail colouring:
  • Tinea unguium (filamentous fungi)
  • After application of nail polish
  • After application of potassium permanganate baths
  • Oil stain, psoriatic
  • Smoker (cigarette or cigar smoker)
  • Systemic drugs (tetracyclines possibly in combination with sunlight exposures; see below) onycholysis, drug-induced or light-induced)
  • Systemic diseases (e.g. Yellow-nail syndrome).
• Orange nail color:
  • After application of nail polish
  • Carrot Icterus ( Aurantiasis cutis)
  • After working with azo dyes.
• Brown or brown-black nail colouring:
  • narrow or broad band longitudinal linear
    • Melanin inclusions
    • Melanonychia striata longitudinalis (clarification of dignity!).
  • Bounded centrally or laterally (never embedded in the nail matrix in stripes (check at the free end of the nail)
  • Older nail hematoma.
• Diffuse homogeneous nail coloration:
  • M. Addison
  • Older nail hematoma: colour mostly deep black (especially on the big toe nail)
  • Medicines (cyclophosphamide; chlorpromazine)
  • Large malignant melanoma or large melanocytic nevus
  • In combination with onychogrypose and polyneuropathy in elderly people
  • Working materials (e.g. photo developer).
• White discolorations (see below Leukonychie).

• Colour anomalies depend on the nail bed, the transparency and adherence of the nail.
• Cause for a nail discoloration can be:
  • Overproduction of melanin (longitudinal or complete brown or black discoloration) (see below for an overview of melanonychia)
  • Formation of coloured new formations of the nail bed (e.g. glomus tumour).
  • Colour deposits (homogeneously large-area, circumscribed, striped lengthwise or crosswise) in the nail bed and/or the nail matrix e.g.:
    • Haematomas (see below haematoma, nail haematoma)
    • copper, silver or mercury (e.g. in the case of M. Wilson or the Argyrie)
    • various drugs (e.g. tetracyclines)
    • Infections (inclusions of coloured microbiological products, e.g. green-blue due to Pseudomonas aeruginosa infection = green nail syndrome).
  • Surface discolorations (e.g. chemicals, most frequently by coloured nail varnish); a preferential discoloration of the proximal nail wall can be caused by professional substances (e.g. potassium permanganate) or external agents (e.g. in smokers). A discoloration of the distal lunula border indicates an internal disease.
• White discoloration of the nails represents a polyätiological colour change of the nail plate (see below leukonychia).

1. Haneke E (2013) Nail diseases. dermatologist 54: 519-532
2. Hengge UE et al (2009) Green nails. New Engl J Med 360: 1125
3. Roh M et al (2007) A case of chromonychia with hyperbilirubinemia. J Eur Acad Dermatol Venereol 21: 127-128