Differential Diagnosis for Nail Linear Dark
- Single most likely diagnosis
- Melanonychia: This condition is characterized by a linear dark streak in the nail, often caused by an increase in melanin production. It can be benign or associated with melanoma.
- Other Likely diagnoses
- Nail trauma: Trauma to the nail can cause linear dark streaks due to bleeding or inflammation under the nail plate.
- Nail fungus (onychomycosis): Certain types of fungal infections can cause dark discoloration of the nail, including linear streaks.
- Vitamin deficiencies: Deficiencies in vitamins like B12 or vitamin C can cause changes in nail color, including linear dark streaks.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Subungual melanoma: A type of skin cancer that can present as a linear dark streak under the nail. Early detection is crucial for treatment and survival.
- HIV-associated nail changes: Certain nail changes, including linear dark streaks, can be associated with HIV infection.
- Rare diagnoses
- Addison's disease: A rare endocrine disorder that can cause hyperpigmentation, including linear dark streaks in the nails.
- Peutz-Jeghers syndrome: A rare genetic disorder characterized by intestinal polyps and mucocutaneous melanin deposits, which can cause linear dark streaks in the nails.
- Laugier-Hunziker syndrome: A rare condition characterized by hyperpigmentation of the nails, lips, and oral mucosa, which can cause linear dark streaks in the nails.