Question: Can you identify this condition?

A 42-year-old woman, who works as a dishwasher at a restaurant, has a 6-month history of a greenish nail on her left toe. The discoloration is an isolated clinical finding. She is not taking any medications and her medical history is unremarkable.

The most likely diagnosis is

1. Pseudomonas aeruginosa infection

2. Chronic nail trauma

3. Tinea unguium

4. Malignant melanoma

5. Subungual hematoma

Answer on page 1104