Melanonychia

Table 1

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

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Melanonychia

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Melanocytic activation

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Physiologic causes

 Racial melanonychia

 Pregnancy

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Local and regional causes

 Repeated local trauma from poor footwear or overriding toes

 Onychotillomania

 Nail biting

 Occupational trauma

 Carpal tunnel syndrome

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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

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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

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Iatrogenic causes

 Phototherapy

 X-ray exposure

 Electron beam therapy

 Drug intake^*—please see Table 2

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Syndromes

 Laugier-Hunziker syndrome

 Peutz-Jegher syndrome

 Touraine syndrome

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Melanocytic hyperplasia

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Lentigo

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Nevus

 Congenital nevi

 Acquired nevi

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Nail apparatus Insitu and invasive melanoma

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