Differential Diagnosis for Green Color on Nail Bed
- Single most likely diagnosis
- Pseudomonas infection: This is a common cause of green discoloration on the nail bed, often seen in patients with onycholysis (separation of the nail from the nail bed) or those who have exposed their hands to water for prolonged periods, allowing Pseudomonas bacteria to colonize under the nail.
- Other Likely diagnoses
- Fungal infection: Certain fungal infections can cause discoloration of the nail, including greenish hues, although this is less common than other colors like yellow or brown.
- Trauma: A green color under the nail can also appear after trauma, due to the formation of a hematoma that changes color over time.
- Nail polish or dye: Sometimes, the green color can be due to staining from nail polish or dyes.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Malignant melanoma: Although rare, a greenish discoloration can be a sign of malignant melanoma under the nail, known as subungual melanoma. This condition is serious and requires prompt medical attention.
- Squamous cell carcinoma: Another type of skin cancer that can present under the nail, though less common than melanoma.
- Rare diagnoses
- Arsenic poisoning: Chronic exposure to arsenic can lead to various skin and nail changes, including pigmentation changes that might appear greenish.
- Wilson's disease: A genetic disorder that leads to copper accumulation in the body, which can cause a range of symptoms including nail changes, though green discoloration is not the most common presentation.