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MelanonychiaL60.8
Synonym(s)
black nail; black nail discolouration; black nails; Melanonychia; Melonychia
DefinitionThis section has been translated automatically.
Polyätiological, mostly painless, localized - streaky or roundish - but also diffusely homogeneous, black or brown-black discoloration of the nail plate, the subungual tissue or the paro/perinychium (see nail below), which occurs on one or more nail organs and has a high diagnostic significance with regard to the development of a malignant melanoma. Melanonychia can be associated with or without nail dystrophy.
ClassificationThis section has been translated automatically.
Homogeneous even discolouration
- Tumor formations
- Malignant melanoma of the nail matrix
- Exogenous discolouration
- Potassium permanganate
- Dirt
- Tobacco discoloration
Striped discoloration
- Melanonychia striata longitudinalis
- Pigment-forming fungi (e.g. moulds, Trichophyton rubrum var. nigricans)
EtiopathogenesisThis section has been translated automatically.
Melanocytic, microbiological, traumatic, proliferative or exogenous factors:
- Melanocytic causes (Melaninonychia)
- Physiological in coloured people
- Melanocytic nevus of the nail root or nail bed
- Malignant melanoma of the nail root or nail bed
- Laugier-Hunziker syndrome.
- Exogenous causes:
- Antibiotics (e.g. tetracyclines)
- Antimalarials ( Chloroquine, Cyclophosphamide)
- Anticonvulsants ( phenytoin)
- Cytostatic drugs (Hydroxyurea)
- Virustatics
- Dithranol
- Silver nitrate
- Potassium permanganate baths(intensive brown discoloration).
- Metabolic diseases:
- Microbiological causes:
- Fungal colonization:
- Trichophyton soudanense
- Alternaria tenuissima
- Fusarium oxysporum
- Scytalidium dimidiatum
- Bacterial causes:
- Pseudomonas aeruginosa
- Proteus spp.
- Fungal colonization:
- Other:
- haematoma (important differentiation from subungual malignant melanoma)
- Lichen planus.
Differential diagnosisThis section has been translated automatically.
The most important differential diagnostic decision is the differentiation between melanocytic and non-melanocytic pigmentation. In case of melanocytic pigmentation of the nail matrix there is always a continuous striped pattern. This is never observed in subungual haematoma (most common differential diagnosis). Microbially caused nail discolorations are generally accompanied by dystrophic changes in the nail matrix (see Tinea unguium).
TherapyThis section has been translated automatically.
After differential diagnostic clarification, therapy according to etiology (e.g. melanoma, subungual).
LiteratureThis section has been translated automatically.
- Haneke E (2013) Nail diseases. dermatologist 64: 519-532