Melanonychia

Melanonychia
Synonyms
Pronounce	N/A
Specialty	Dermatology
Symptoms	Brown or black pigmentation of the nail
Complications	Possible subungual melanoma
Onset
Duration
Types	Longitudinal melanonychia, diffuse melanonychia
Causes	Melanocyte activation, melanocytic nevus, melanoma, trauma, medications
Risks
Diagnosis	Clinical examination, dermoscopy, biopsy
Differential diagnosis	Subungual hematoma, onychomycosis, nail psoriasis
Prevention
Treatment	Depends on underlying cause; may include observation, surgical excision
Medication
Prognosis	Varies; benign in most cases, but can indicate malignancy
Frequency	Common
Deaths	N/A

Melanonychia is a medical condition characterized by a brown to black discoloration of a nail. This discoloration is caused by an increased amount of melanin in the nail. Melanonychia can affect both fingernails and toenails, and can occur at any age.

Causes

Melanonychia can be caused by a variety of factors, including:

• Trauma to the nail
• Infections, such as fungal infections
• Certain medications
• Certain diseases, such as HIV or Addison's disease
• Melanoma, a type of skin cancer

Symptoms

The main symptom of melanonychia is a brown to black discoloration of one or more nails. This discoloration may be uniform or irregular, and may affect the entire nail or only a portion of it. In some cases, the affected nail may also become thickened or distorted.

Diagnosis

Diagnosis of melanonychia typically involves a thorough examination of the affected nail and a review of the patient's medical history. In some cases, a biopsy of the nail may be necessary to rule out melanoma.

Treatment

Treatment for melanonychia depends on the underlying cause. If the discoloration is caused by a medication, for example, discontinuing the medication may resolve the condition. If the discoloration is caused by a disease, treating the disease may also resolve the melanonychia. In cases where melanonychia is caused by melanoma, treatment may involve surgery to remove the affected nail and underlying tissue.

See also

• Nail disease
• Melanoma
• Melanin