Answer:
Nick observes thickening and discoloration of the nail of the index finger. Nick is most likely suffering from an onychomycosis infection.
Explanation:
Onychomycosis is a chronic and progressive infection of the nails caused by fungi. In most cases it is produced by dermatophytes, and less frequently by yeasts and molds. It is the most frequent nail disease.
Onychomycosis can affect the appearance, thickness and color abnormally, both in the nails of the hands and the feet, although the nail of the big toe is the most frequently affected.
