|
| Melanonychia |
|
| Melanocytic activation |
|
| Physiologic causes |
| Racial melanonychia |
| Pregnancy |
|
| Local and regional causes |
| Repeated local trauma from poor footwear or overriding toes |
| Onychotillomania |
| Nail biting |
| Occupational trauma |
| Carpal tunnel syndrome |
|
| Dermatologic causes |
| Onychomycosis |
| Chronic paronychia |
| Psoriasis |
| Lichen planus |
| Amyloidosis |
| Chronic radiation dermatitis |
| Systemic lupus erythematosus |
| Localized scleroderma |
| Onychomatricoma |
| Bowen’s disease |
| Myxoid pseudocyst |
| Basal cell carcinoma |
| Subungual fibrous histiocytoma |
| Verruca vulgaris |
| Subungual linear keratosis |
|
| Systemic causes |
| Endocrine disorders (Addison’s disease, Cushing’s syndrome, |
| Nelson’s syndrome, hyperthyroidism, and acromegaly) |
| Alcaptonuria |
| Nutritional disorders |
| Hemosiderosis |
| Hyperbilirubinemia |
| Porphyria |
| Graft versus host disease (lichen planus-type changes |
| accompanied by longitudinal melanonychia) |
| AIDS |
|
| Iatrogenic causes |
| Phototherapy |
| X-ray exposure |
| Electron beam therapy |
| Drug intake*—please see Table 2 |
|
| Syndromes |
| Laugier-Hunziker syndrome |
| Peutz-Jegher syndrome |
| Touraine syndrome |
|
| Melanocytic hyperplasia |
|
| Lentigo |
|
| Nevus |
| Congenital nevi |
| Acquired nevi |
|
| Nail apparatus Insitu and invasive melanoma |
|