Melanonichia

Melanonichia Melanonichia is brown or black pigmentation of the nail. Has two forms: diffuse and melanonichia melanonichia longitudinal. The most important cause of melanoma is melanonichiei subunghial, although other causes include melanochia longitudinal psychological cause systemic inflammatory diseases, fungal infections, drugs and benign hyperplasia melanocitice: nevi, lentigo.
Psychological Melanonichia is encountered especially in dark individuals, and people affected increases with age prevalent. Longitudinal bands tend to be multiple and poorly pigmented. In melanoma subunghial there was only one band. Morbidity and mortality associated with melanonichia depend on the underlying cause. Melanonichia subunghial secondary source of both melanoma, with survival rates at 5 and 10 years of 30% and 13% respectively.
If melanonichia is secondary to systemic disease or dermatologic treatment is important to them. If a secondary drug discontinuation is recommended. If one thinks in situ malanom indicate total excision or Mohs microsurgery. In the invasive melanoma phalanx amputation is recommended. Cases of advanced melanoma carries a poor prognosis.
Pathogenesis
Melanonichia occurs due to increased melanin production by melanocytes in the nail matrix. In healthy people the normal number is malanocite 200/mm2, most of which remain dormant. When they are activated melanosomii filled with melanin are transferred differentiated matrix cells that migrate distally and become onicocite, forcing a visible colored band.
Causes and Risk Factors
Hyperplastic cases: -Melanoma, lentigo, nevi melanocitici (band width is more than 3 mm in 50% of cases. Psychological causes: pregnancy (multiple bands), racial melanochia (multiple bands from African, Hispanic, Indian, Japanese).
Local and regional cases: -Trauma, narrow shoes, onicotilomania, insect bites Carpal-tunnel syndrome, foreign body subunghial, radiotherapy Ultraviolet-light, postinflamatorie hyperpigmentation.
Systemic causes: , Addison disease, Cushing syndrome, Nelson syndrome, hyperthyroidism -Hemosideroza, hyperbilirubinemia, alcaptonuria, porphyria, HIV infection Graft-versus host disease, malnutrition, vitamin B12 deficient.
Causes skin: -Psoriasis, Lichen Planus, radiodermatitis chronic scleroderma Lupus erythematosus-, fungal nail infections, basal cell carcinoma -Bowen's disease, fibrous histiocitomul subunghial, lichen streaked, mucous cyst.
Pharmacological Causes: -Bleomycin, busulfan, cyclophosphamide, dacarbazine, danuorubicina -Doxorubicin, etoposide, 5-fluorouracil, hydroxyurea, methotrexate. -Arsenic, cloroquina, cyclins, fluconazole, gold salts, ibuprofen, ketoconazole -Minocycline, phenytoin, phenothiazines, psoralen, mercury, lamivudine, tetracycline -Steroids, sulfonamides, timolol, zidovudine.
Signs and symptoms
Typically melanonichia is more common in older people, although it can occur in children. The number and width of the bands increases with age. Most asymptomatic patients have a history of pigmentation of the nail. Careful anamnesis should include medications, illnesses suffered, habits, family medical history and racial origin. In malignant melanoma patient describes a longitudinal melanonichie band who has recently changed. Changes include alterations characteristic of melanoma color, size and shape of the band or the appearance of pain or local ulcerarii.
Physical examination. Melanonichia is characterized by a brown or black discoloration of the nail. This can be affected only diffuse or longitudinally. Transverse melanonichia rarely reported. Can be involved one or more fingers.
The following factors raise the possibility of malignant etiology melanonichiei: -A-age-incidence in the seventh decade B-brown-black band over 3 mm wide C-change morphology -D-thumb toe is affected more often than E-extension of pigment from the matrix, nail bed, cuticle or nail folds of the lateral F-melanonichie positive family medical history.
Treatment
If melanonichia systemic or dermatologic diseases are due to be trying their treatment. If it is secondary to the administration of a drug can be stopped if it is not vital and melanonichia disappears. Surgery is indicated in cases of malignant malanom. The practice of excision of melanoma in situ nail apparatus or Mohs micrographic surgery. In the case of invasive melanoma is practiced Mohs surgery or amputation of the distal phalanx. Patients with idiopathic melanonichie unwilling longitudinal biopsy should be monitored and evaluated every 3 months for changes. You can use a dermatoscopy to differentiate benign from the malignant form. If the observed changes are suggestive of melanoma, and the index of suspicion is high lesion biopsy is indicated. The most common complication of surgery is nail dystrophy. Most cases are benign primary melanochie with limited morbidity and mortality. Melanoma prognosis is negative.