II. Definitions
- Chromonychia (dyschromia)
- Color changes of nails
III. Causes: White Nail - Leukonychia (partial or complete)
- Anemia (most common)
- Congenital (Autosomal Dominant)
- Abnormal keratinization of underlying nail matrix
- Results in nail plate white discoloration of one or multiple nails with all or partial nail involvement
- No Clinical Significance (normal variant in adults and children)
-
Terry's Nails (all White Nails except the distal 1-2 mm nail edge)
- Chronic Liver Disease
- May also occur with Diabetes Mellitus, Congestive Heart Failure, Hyperthyroidism, Aging
- Half and Half Nails (Lindsay's Nails, white proximal, pink/red distal)
-
Transverse Linear Nail Lesions
- Muehrcke's Lines
- Mees' Lines
- Transverse striate Leukonychia (white lines)
- Minor nail matrix or cuticle Trauma
- Leukonychia punctata (white spots)
- Minor Trauma to Nail Cuticle or matrix
IV. Causes: Miscellaneous Color Changes
-
Green Nails (Chloronychia)
- Pseudomonas pyocyanea or Pseudomonas aeruginosa infection
- Red Nails
V. Causes: Blue Nails
- Medication Side Effect
- Quinacrine
- Chloroquine
- Minocycline (Minocin)
- Doxorubicin (Adriamycin)
- Melphalan, Bleomycin, Daunorubicin
- Wilson's Disease (Azure lunula)
- Ochronosis
- Psoriasis
- Alopecia Areata
- Silver Poisoning (Argyria)
VI. Causes: Diffusely Black Nails (Melanonychia), Hyperpigmentation or Dark Longitudinal Streaks
- See Nail Abnormality (includes other longitudinal striations)
- See Hyperpigmentation
- Nail Hyperpigmentation is common
- Black patients have a 75% Prevalence of benign Nail Hyperpigmentation
- However, involvement of a single nail (esp. first), and esp. in a linear arrangement is concerning
- Represents Subungual Melanoma in 5% of caucasian and 15-20% of black, asian
-
Subungual Melanoma
- Most important diagnosis to exclude (esp. if isolated, single nail involvement)
-
Vertical Nail Bands (Longitudinal Melanonychia)
- Hyperpigmented bands occur as normal variant in 90% of black patients
- Distinguish from Subungual Melanoma (see below)
- Melanonychia striata
- Common in dark skinned persons
- Spontaneous or secondary to Trauma or Chemotherapy
- Benign Nevus
- Uniform brown longitudinal streak localized to nail
-
Chronic Renal Failure
- Distal nail bed discolored brown
- Melanoderma
- Diffuse skin Hyperpigmentation may also affect the nails
- Other Causes
- Hyperpigmentation in Pregnancy
- Nutritional Deficiency
- Miscellaneous Medication Side Effects
- Excessive Fluoride Supplementation (Fluorosis)
- Antimalarials
- Phenytoin
- Tetracycline
- Chemotherapeutics
- Connective Tissue Disease
- Endocrinopathy
- Addison Disease
- Cushing Syndrome
- Hypothyroidism
VII. Causes: Yellow Nails
VIII. References
- Jhun, Raam and DeClerck in Herbert (2015) EM:Rap 15(12): 3-4
- Fawcett (2004) Am Fam Physician 69(6):1417-24 [PubMed]
- Hashimi (2023) Am Fam Physician 107(3): 305-6 [PubMed]
- Mendiratta (2011) Indian J Dermatol Venereol Leprol 77(6):652-8 +PMID: 22016271 [PubMed]