II. Epidemiology
- Normal variant in 90% of black patients
- Uncommon in lighter skinned patients
III. Signs
- Hyperpigmented longitudinal band
- May involve entire length of nail and affect one or multiple nails
IV. Differential Diagnosis
- See Melanonychia
- See Nail Longitudinal Band
-
Subungual Melanoma (50% of Melanomas in dark skinned patients)
- Critical to distinguish from the benign Vertical Nail Bands
V. Evaluation
- Biopsy suspicious Longitudinal Melanonychia