Review Article
Melanonychia
Table 1
Classification of conditions associated with longitudinal melanonychia. Table adapted from J. Andre, N. Lateur. Pigmented nail disorders [
2].
| 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 |
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