Differential Diagnosis for Linear Hyperpigmentation of the Nail
Single Most Likely Diagnosis
- Melanonychia: This is the most common cause of linear hyperpigmentation of the nail, often resulting from activation or proliferation of melanocytes in the nail matrix. It can be caused by various factors, including trauma, infection, or systemic diseases.
Other Likely Diagnoses
- Nail trauma: Trauma to the nail can cause linear hyperpigmentation due to the disruption of melanin production.
- Infection: Fungal or bacterial infections, such as onychomycosis or paronychia, can lead to linear hyperpigmentation of the nail.
- Systemic diseases: Certain systemic diseases, such as Addison's disease or vitamin B12 deficiency, can cause linear hyperpigmentation of the nail.
Do Not Miss Diagnoses
- Subungual melanoma: Although rare, subungual melanoma is a potentially deadly condition that can present with linear hyperpigmentation of the nail. It is essential to consider this diagnosis to ensure prompt treatment.
- Hutchinson's sign: This is a specific type of subungual melanoma that presents with pigmentation of the nail and surrounding skin.
Rare Diagnoses
- Laugier-Hunziker syndrome: A rare condition characterized by linear hyperpigmentation of the nails, lips, and oral mucosa.
- Peutz-Jeghers syndrome: A genetic disorder that can cause linear hyperpigmentation of the nails, as well as other mucocutaneous lesions.
- Nail pigmentation due to medication: Certain medications, such as minocycline or hydroxychloroquine, can cause linear hyperpigmentation of the nail as a side effect.